1
Q
SUMMARY CARD:
What is a mycobacterium?
How does it stain?
Clue: AFB
A
Mycobacterium = non-motile rods, obligate aerobes, acid-fast bacteria (AFB)
Gram +ve (but does not take up the gram stain well) therefore, use AFB staining:
- Auramine = SCREENING test: flourescent stain –> yellow (more sensitive but less specific than ZN)
Ziehl-Neelson stain: carbol fuschin & methylene blue –> AFB goredon a blue background
2
Q
SUMMARY CARD:
What are the different types of mycobacterium?
TB, avium complex, abscessus, marinum, ulcer, leprae
A
- Mycobacterium tuberculosis:
caeseating granulomas(cottage-cheese central necrosis), Mx = RIPE - Mycobacterium avium complex: slow-growing, associated with
pre-existing lung disease(e.g.immunocompromised/structural lung problem), found in food / water/ soil; types = intracellulare, avium and chimaera - Mycobacterium abscessus complex: rapid-growing and more common in
CF, Mx =macrolide(e.g. clarithyromycin); types = abscessus, massilense, boleletii - Mycobacterium marinum: live in water; exposure to
fish–> swimming pool granulomas (subcutaneous nodules) - Mycobacterium ulcerans: more common in tropics / Australia –>
buruli ulcer(chronic progressive painless ulcer) - Mycobacterium leprae (
leprosy): more common in Africa, Sx =nervedamage (peripheral neuropathy),depigmentationof the skin
3
Q
SUMMARY CARD:
- Primary vs Latent TB
- Extra-pulmonary presentations of TB
- Ix?
- Mx?
- SEs of Mx?
A
- If infected with TB –> primary = symptomatic; latent = aymptomatic
- Primary:
caseatinggranulomas (‘cheese like’), fever, night sweats, weight loss, cough, haemoptysis - Latent:
Gohn focus= granuloma with necrosed centre created via macrohphages and phagocytosis
- Extra-pulmonary Sx:
Lymphadenitis(most common), pericarditis, peritonitis, renal- Subacute meningitis: headaches, personality change, meningism
- Spinal: Pott’s disease = back pain, discitis
- Miliary TB: disseminated haematogenous spread (CXR =
millet seeds)
- Ix:
ACTIVE TB:
- CXR: R upper lobe cavitation
- Sputum smear =
Ziehl-Neelson (red) - Sputum culture =
Lowenstein-Jensenmedium for 6wks = GOLD STANDARD –> shows acid fast bacili
LATENT TB:
- Tuberculin skin test (Mantoux) = shows exposure to TB (active/latent/
BCG) - IGRA (Interferon-Gamma Release Assays): shows exposure (active/latent -
NOT BCG)
- Management:
ACTIVE TB: 4 for 2, 2 for 4
RIPE:Rifampacin +Isoniazid (w/ pyridoxine) +Pyrazinamide +Ethambutol = all 4 for 2 monthsRifampacin +Isoniazid (w/ pyridoxine) = these 2 for further 4 months
NOTE: meningeal TB = RIPE for 12 months + steroids
LATENT TB:
- Isoniazid (w/ pyridoxine) for 6 months
- OR Rifampacin + Isoniazid (w/ pyridoxine) for 3 months
NOTE: prophylaxis = isoniazid 8-12 weeks (in children < 5 y/o)
- SEs of RIPE:
Rifampicin –> ‘pissing’ = orange secretions, hepatotoxicity
Isoniazid –> ‘I-so-NUMB-azid’ = peripheral neuropathy (that’s why given with B6), hepatotoxicity
Pyrazinamide –> hepatotoxicity, arthralgia, ↑ urea = goutEthambutol –> ‘Eye’ = optic neuritis
4
Q
SUMMARY CARD:
Mycobacterium leprae (leprosy)
1. Sx?
2. Mx?
A
Paucibacillary (tuberculoid): limited skin disease (hypoprigmentation), asymmetric nerve involvement, hair loss
Multibacillary (lepromatous): extensive skin involvement (hypoprigmentation) + symmetrical nerve involvement
Mx: rifampicin, dapsone + clofazimine (triple therapy)
5
Q
DISEASE:
What is the granuloma in latent TB called?
A
Gohn focus
6
Q
DISEASE:
What is spinal TB called?
A
Pott’s disease
7
Q
DISEASE:
What is seen on CXR for miliary TB?
A
Millet seeds
8
Q
DISEASE:
What are the investigations for active TB?
imaging; smears; medium
A
CXR: R upper lobe cavitation- Sputum smear =
Ziehl-Neelson (red) - Sputum culture =
Lowenstein-Jensenmedium for 6wks = GOLD STANDARD –> shows acid fast bacili
9
Q
DISEASE:
What are the investigations for latent TB?
A
- Tuberculin skin test (Mantoux) = shows exposure to TB (active/latent/
BCG) - IGRA (Interferon-Gamma Release Assays): shows exposure (active/latent -
NOT BCG)
10
Q
DISEASE:
What is the Mx for active TB?
BONUS: what is the Mx for latent TB?
A
RIPE:Rifampacin +Isoniazid (w/ pyridoxine) +Pyrazinamide +Ethambutol = all 4 for 2 monthsRifampacin +Isoniazid (w/ pyridoxine) = these 2 for further 4 months
NOTE: meningeal TB = RIPE for 12 months + steroids
BONUS: LATENT TB:
* Isoniazid (w/ pyridoxine) for 6 months
* OR Rifampacin + Isoniazid (w/ pyridoxine) for 3 months
11
Q
DISEASE:
Caseating granuloma, night sweats, haemoptysis, recently travelled to Asia
- What is the diagnosis?
- What are the SEs of the Mx?
A
- TB
- SEs:
- Rifam
picin–> ‘pissing’ = orange secretions, hepatotoxicity - Isoniazid –> ‘I-so-NUMB-azid’ = peripheral neuropathy (that’s why given with B6), hepatotoxicity
- Pyrazinamide –> hepatotoxicity, arthralgia, ↑ urea = gout
Ethambutol –> ‘Eye’ = optic neuritis
12
Q
DISEASE:
What is the BCG vaccine?
A
Bacille-Calmette-Guerin
Live-attentuated strain of M. bovis given to high-risk patients
CI = immunosuppressed patients (due to it being a live vaccine)
13
Q
DISEASE:
Depigmentation of skin + nerve thickening & peripheral neuropathy; ZN stain shows AFB
What is the causative organism?
A
Mycobacterium leprae –> causes leprosy
14
Q
DISEASE:
Disseminated infection in immunocompromised
Slow-growing
ZN stain shows AFB
What is the causative organism?
A
Mycobacterium avium complex
15
Q
DISEASE:
PMHx = CF, rapid-growing, ZN stain shows AFB
What is the causative organism?
BONUS: Mx?
A
Mycobacterium abscessus
Mx = macrolide e.g. clarithromycin
16
Q
DISEASE:
Australia / tropics, painless nodules progressing to ulceration, scarring, contractures
What is the causative organism?
BONUS: name of ulcers
A
Mycobacterium ulcerans
BONUS: Buruli ulcer
17
Q
DISEASE:
Aquarium owner, subcutaneous nodules
What is the causative organism?
A
Mycobacterium marinum
18
Q
SUMMARY CARD:
What are the different ways of classifying pneumonia?
A
1. CAP vs HAP:
- HAP =
>48hrsafter hospital admission - Common HAP = S. aureus, Klebsiella, Pseudomonas, Haemophilus
2. Typical vs Atypical:
- Typical =
classicrapid development of signs and symptoms, classic CXR changes (e.g. consolidation),responsive to penicillin Abx - Atypical = no / atypical signs e.g. dry cough,
does not respondto penicillin Abx (because no cell wall), more responsive to macrolides e.g. clarithromycin; extra-pulmonary Sx e.g. rashes, hepatitis, hyponatraemia
19
Q
SUMMARY CARD:
Typical pneumonia organisms:
A
- Strep. pneumoniae: most common,
rusty-coloured sputum; CXR = lobar; microscopy =+ve diplococci - Haemophilus influenzae: associated w/ pre-existing lung disease (e.g. COPD, bronchiectasis); CXR = bronchoalveolar pattern (lower lobes), “
glossy colonies”; microscopy = -ve cocco-bacilli - Moraxella catarrhalis: associated w/ smoking and underlying lung disease; microscopy = -ve cocci
- Staphylococcus aureus: recent viral infection, CXR = cavitatation; microscopy =
+ve cocci“grape bunchclusters” &coagulase +ve - Klebsiella pneumoniae: alcoholics & diabetics, haemoptysis (
red-currant jelly sputum), CXR = upper lobe cavitation; microscopy = -ve bacilli
20
Q
SUMMARY CARD:
Atypical pneumonia organisms (including fungal):
Clues: legionella, mycoplasma, chlamydia, Q fever, pertussis, TB, burkholderia, pseudomonas, aspergillus, PCP
A
Legionella pneumophilia:water/air conditioning, confusion, hepatitis,hyponatreaemia, urinary antigen +ve; charcoal yeastMycoplasma pneumoniae: uni students / boarding schools, dry cough, arthralgia, cold agglutination,erythema multiformeand target shaped lesions on palm; Mx: macrolideChlamydia pneumoniae: children and adolescentsChlamydia psittaci:birds, haemolytic anaemia, splenomegaly, rose spots- Coxiella burnetii: AKA
Q fever, exposure to farm animals; microscopy = -ve coccobacilli - Bordetella pertussis: AKA
whooping cough, unvaccinated (immigrant); microscopy = -ve coccobacilli - Mycobacterium tuberculosis: prolonged flu-like prodrome w/
TB symptoms; CXR = upper lobe cavitation or “millet seed” (miliary TB); microscopy =+ve bacilli - Burkholderia cepecia: associated w/ CF, persistent infection and
poor prognosis; microscopy = -ve bacilli - Pseudomonas aeruginosa: CF; Mx: Tazocin OR ciprofloxacin +/- gentamicin; microscopy = -ve coccobacilli
- Aspergillus fumigatus (fungi): fungal ball in pre-existing (usually TB) cavity, CXR =
Halo sign, neutropenia - Pneumocystis jiroveci (fungi): associated with HIV, CXR = Bat’s wing, HRCT =
bilateral ground-glass shadowing; silver stain +ve = cysts; histology = boat shapes; Mx: co-trimoxazole
21
Q
SUMMARY CARD:
Which organisms do the following immunosuppressions predispose you to:
1. HIV
2. Splenectomy
3. CF
4. Neutropenia
A
- HIV:
pneumocystitis jiroveci, TB - Splenectomy:
NHS= neisseria meningitidis, haemophilus influenzae, strep. pneumoniae - CF:
pseudomonasaeruginosa, burkholderia cepacia - Neutropenia:
aspergillus
22
Q
DISEASE:
Mx for pneumoniae:
1. What scoring system is used?
2. Typical (+ legionella + staph)
3. Atypical: PCP, pseudomonas, MRSA
4. HAP (+severe HAP)
3. Aspiration
4. Anaerobic
A
CURB-65 –> 1 point for confusion, urea >7, RR>30, BP < 90/60, > 64 y/o
- CURB-65 0-1 (
mild): outpatient –> amoxicillin PO 5 days; if pen allergy then macrolide PO 5 days - CURB-65 2 (
mod): consider admission –> amoxicillin PO 5-7 days + clarithyromyin PO 5-7 days - CURB-65 3-5 (
severe): admit +/- consider ITU –> co-amoxiclav IV 7 days + clarithromycin IV 7 days Legionella: Clarithromycin + RifampicinStaphylococcus: Flucloxacillin
ATYPICALS:
PCP(pneumocystitis jiroveci): co-trimoxazolePseudomonas: tazocin OR ciprofloxacin +/- gentamicinMRSA: vancomycin
HAP: ciprofloxacin + vancomycinSevere HAP: tazocin + vancomycin
ASPIRATION: tazocin + metronidazole
ANAEROBIC bacteria: clindamycin +/- metronidazole
23
Q
DISEASE:
rusty-coloured sputum
CXR = lobar consolidation
microscopy = +ve diplococci
Had a SPLENECTOMY
no confusion, urea < 7, RR < 30, BP > 90/60, age > 65
- Causative organism?
- Mx?
A
Strep pneumoniae (typical)
CURB-65 is 1 = mild –> amoxicillin PO 5 days
Note: splenectomy predisposes to NHS organisms (Neisseria meningitides, haemophilus influenzae, streptococcus pneumoniae)
24
Q
DISEASE:
PMHx = COPD
cough, haemoptysis
CXR = bronchoalveolar ‘glossy colonies’ in the lower lobes
- Causative organism?
- Microscopy?
A
- Haemophilus influenzae (typical)
- -ve coccibacilli
25
# DISEASE:
**recent URTI**
CXR = cavity
microscopy = `+ve cocci clusters`
1. Causative organism?
2. BONUS: which protein enzyme +ve?
3. Mx?
1. Staph aureus (typical)
2. coagulase +ve
3. Flucloxacillin
26
# DISEASE:
Diabetic + alcoholic
`redcurrant jelly sputum`
CXR = **upper lobe cavity**
1. Causative organism?
2. microscopy?
1. Klebsiella pneumoniae (typical)
2. -ve bacilli
27
# DISEASE:
recent trip from abroad, stayed in `air conditioned` hotel
confused
**hyponatraemia**
hepatitis
1. Causative organism?
2. Mx?
1. legionella pneumophilia
2. Clarithromycin + rifampicin
28
# DISEASE:
**Uni** student, lives in **halls** with many other students
**dry cough, arthralgia**
**cold agglutins**
`ethythema multiforme` (target shaped rash on palms)
No culture (with sputum or CSF) and nothing shows up on gram stain
1. Causative organism
2. Mx?
1. Mycoplasma pneumoniae
2. Macrolide e.g. clarithromycin
29
# DISEASE:
Works with `birds`
**haemolytic anaemia**
**splenomegaly**
rose spots
1. Causative organism?
1. Chlamydia psittaci
30
# DISEASE:
Exposure to farm animals
Histology: -ve coccobacilli
1. Causative organism (+ diagnosis)?
| hint: 1 letter
Coxiella burnetii (AKA Q fever)
31
# DISEASE:
Unvaccinated immigrant
Paroxysmal coughing w/ inspiratory whoop
1. Causative organism (+ diagnosis)?
2. Mx?
`Bordetella pertussis` (AKA **whooping cough**)
Mx = Abx if cough < 21 days of onset --> **macrolides**:
< 1 month old = `clarithromycin`
>1 month old = `azithromycin`
(if macrolides CI, consider co-amoxiclav)
Return to school 2 days after commencing abx Tx **OR** 21 days after cough onset
32
# DISEASE:
prolonged flu-like prodrome
`haemoptysis`
CXR = **cavitation** in upper lobe
**HIV +ve**
1. Causative organism (+ diagnosis)
2. What is seen on microscopy?
1. Mycoplasma tuberculosis (AKA TB)
2. gram +ve bacilli
33
# DISEASE:
PMHx: **CF**
`Persistent infection + poor prognosis`
histology: gram **-ve rod**
1. Causative organism?
1. Burkholderia cepecia
34
# DISEASE:
PMHx: **CF**
histology: gram `-ve coccobacilli`
1. Causative organism?
2. Mx?
| moan
Pseudomonas aeruginosa
Mx = Tazocin **OR** ciprofloxacin +/- gentamicin
35
# DISEASE:
**Neutropenia**
CXR = `halo sign`
1. Causative organism?
| (FUN GUY)
aspergillus fumigatus
36
# DISEASE:
PMHx: HIV
CXR = **Bat’s wing**
HRCT = `bilateral ground-glass shadowing`
Microscopy = '`boat-shapes`'
1. Causative organism?
2. What type of staining is +ve?
3. Mx?
1. Pneumocystitis jiroveci
2. silver stain +ve
3. co-trimoxazole
37
# DISEASE:
Pt develops pneumonia 8 days after being admitted to the hospital wards
1. Mx?
2. BONUS: Mx for severe HAP
HAP = develop pneumonia >2 days after being admitted to hospital
Mx = ciprofloxacin + vancomycin
Severe HAP Mx = tazocin + vancomycin
38
# DISEASE:
Elderly patient with altered mental status, fever, and cough, diagnosed with aspiration pneumonia
1. Mx?
tazocin + metronidazole
39
# DISEASE:
Anaerobic bacteria causing pneumonia
1. Mx?
clindamycin +/- metronidazole
40
# SUMMARY CARD:
How to differentiate between:
1. Bronchitis
2. Pneumonia
3. Lung abscess
4. Emphysema
| symptomatically
1. Bronchitis: affects normal sized vessels, `normal CXR`
2. Pneumonia: **unwell** pt + affects lung parenchyma
3. Abscess: `swinging fevers` + cavity in lung parenchyma, FLAWS, **unresponsive to abx + requires drainage**
4. Emphysema = infected pleural effusion
41
# SUMMARY CARD:
1. What is infective endocarditis?
2. Which valves are most commonly affected?
3. S&S?
4. Ix?
| Hint: Duke criteria
1. bacteria form vegetations on valve(s)
2. Usually affects the valves on the **L side** = `mitral` and aortic --> this is due to increased pressure on L side of heart which causes damage to those valves making it more susceptible to bacterial growth
NOTE: R sided (tricuspid) is most common in **IVDU** (as circulation returns to R side of heart first)
3. S&S: ACUTE = **fever** (pyrexia of unknown origin (PUO)); `new heart murmur` that changes day to day (usually regurgitant), non specific Sx (anorexia, weight loss, malaise, fatigue etc.); **HF, rapidly septic**
NOTE: in subacute infective endocarditis (develops over weeks-months) --> new heart murmur + FLAWS + **embolic phenomena** (e.g. `janeway lesions, splinter haemorrhages, splenomegaly`) & **immune phenomena** (e.g. `roth spots` in eyes, `osler's nodes` in hands, `haematuria due to glomerulonephritis`)
4. Ix: **Blood cultures** = ideally from 3 different sites before starting abx; **echocardiogram**; `DUKE'S CRITERIA`: need 2 major OR 1 major + 3 minor OR 5 minor
42
# SUMMARY CARD:
What are Duke's criteria?
Major:
* **Positive blood culture** growing typical organisms (>2x cultures >12 hrs apart)
* **New regurgitant murmur** OR evidence of vegetation on **echo**
Minor:
* **RFs**: long-term lines (e.g. in ITU), IVDU, poor dentician, prosthetic valve, rheumatic heart disease, immunosuppression
* **Fever** **>38°C**
* Embolic phenomena (e.g. `janeway lesions, splinter haemorrhages, splenomegaly`)
* Immune phenomena (e.g. `roth spots` in eyes, `osler's nodes` in hands, `haematuria due to glomerulonephritis`)
* Positive blood culture not meeting the major criteria
For infective endocarditis diagnosis: need **2 major** OR **1 major + 3 minor** OR **5 minor**
43
# SUMMARY CARD:
Infective endocarditis Mx?
`IV abx for 6 weeks`
Start empirically as soon as cultures taken, then change according to sensitivities
Rule of thumbs:
**ACUTE**: `flucloxacillin` (cause staph aureus most common)
**SUBACUTE**: `benzylpenicillin + gentamicin`
**Prosthetic** valve: `vancomycin + gentamicin + rifampicin`
Consider surgical debridement
44
# SUMMARY CARD:
What are the different pathogens that can cause infective endocarditis?
1. **ACUTE** (`high` virulence bacteria = rapid onset of symptoms):
* Streptococcus `pyrogenes` (Group A strep) = **rheumatic fever**
* `Staph aureus` (most common in **IVDU**)
* `Coagulase-negative staphylococci` (most common in **prosthetic valve**)
2. **SUBACUTE** (`low` virulence bacteria = slower onset of symptoms):
* `Staphylococcus epidermidis` (most common **post-valvular surgery**)
* Streptococcus `viridans` (more common in low resource countries, dental work)
* **HACEK** = do not grow on culture --> `h`aemophilus, `a`cinetobacter, `c`ardiobacterium, `e`ikinella, `k`ingella
45
# DISEASE:
PUO for last 8 weeks (>38°C)
Osler's nodes on hands
New regurgitation murmur
post valvular surgery with prosthetic valve
1. causative organism
2. Mx?
1. **staphylococcus epidermidis** (coagulase negative staphylococcus)
2. Mx = IV `vancomycin + gentamicin + rifampicin`
BONUS: fulfils 1 major and 3 minor of Duke's criteria
46
# DISEASE:
fever for past 4 days, now septic
IVDU
Blood culture grows gram positive diplococci in clusters
1. causative organism (+diagnosis)
2. Mx?
1. staph aureus (infective endocarditis)
2. IV `flucloxacillin`
47
# DISEASE:
Young patient with recent pharyngitis, fever, and new-onset murmur
1. causative organism (+diagnosis)?
1. Strep pyogenes AKA group A strep (AKA rheumatic fever)
48
# DISEASE:
Middle-aged patient with dental procedure history, fever, and new-onset murmur
1. causative organism (+ diagnosis)?
2. streptococcus viridans (causing infective endocarditis)
49
# SUMMARY CARD:
What are the different types of diarrhoea caused by GI infections?
BONUS: which organisms cause which?
1. **Secretory diarrhoea**: `watery diarrhoea, no fever`
* Toxin production causes Cl- to be secreted into the lumen which leads to diarrhoea = loss of water + electrolytes
* **Organisms**: vibrio **cholerae** (`rice water stool`), enterotoxigenic Escherichia Coli (**ETEC**; `traveller's diarrhoea`), Enteropathogenic Escherichia coli (**EPEC**), **bacillus cereus** (`reheated rice`), s**taph aureus** (`short incubation period`)
2. **Inflammatory diarrhoea**: `BLOODY diarrhoea w/ mucus (AKA dysentery)`, **fever**
* Inflammation + bacteraemia
* Organisms: **CHESS**
* `C`ampylobacter jejuni (complication = GBS), `h`aemorrhagic E. coli, `E`ntamoeba histolytica, `S`higella, `S`almonella
3. Enteric fever: unwell with fever, GI symptoms
* Organisms: **salmonella typhi** (typhoid fever), **yersinia** enterocolitica, brucella
50
# SUMMARY CARD:
What are the gram +ve organisms that cause GI infections / diarrhoea?
| 3 types of clostridium, bacillus, staph, listeria
1. **Clostridium botulinum**: toxin blocks Ach release from peripheral nerves = `DESCENDING paralysis`; toxin can be **inactivated by cooking**; from canned / vacuum packed `foods` (honey = kids, beans = students); Mx = antitoxin
2. **Clostridium perfringens**: from reheated meats; 8-16hr incubation and lasts **~24hrs**; **watery diarrhoea + cramps**; causes `gas gangrene` (alpha toxin in infected tissue necroses + releases foul smelling gas)
3. **Clostridium difficile**: causes `pseudomembranous colitis` (looks like **wet cornflakes** on colonscopy); caused by the **4 C's** (`c`ephalosporins, `c`lindamycin, `c`iprofloxacilin, `c`o-amoxiclav); Mx = `IV metronidazole or oral vancomycin`
4. **Bacillus cereus**: cereulide toxin; `reheated fried rice`; watery **non-bloody diarrhoea** + vomiting within **4hrs**; self-limiting
5. **Staphylococcus aureus**: S. aureus enterotoxin = vomiting + watery **non-bloody diarrhoea** with `SHORT incubation period` (< 2hrs); self-limiting
6. **Listeria monocytogenes**: microscopy shows tumbling motility; refrigerated food e.g. `CHEESE` (unpasteurised dairy); **perinatal** infection; severe infection in immunocompromised; Mx = **ampicillin**
NOTE: ALL are gram +ve bacilli except staph aureus (which is gram +ve diplococci in clusters)
51
# SUMMARY CARD:
What are the gram -ve organisms that cause GI infections / diarrhoea?
| 4 E. coli, 2 Salmonella, 3 vibrio, campylobacter, shigella, Yersinia,
1. (entero`t`oxigenic) Escherichia coli (**E`T`EC**): `t`oxigen, `t`raveller's diarrhoea
2. (entero`p`athogenic) Escherichia coli (**E`P`EC**): `p`athogenic, `p`aediatric/infantile diarrhoea
3. (entero`i`nvasive) Escherichia coli (**E`I`EC**): `i`nvasive; **bloody diarrhoea w/cramps** + N/V
4. (entero`h`aemorrhagic) Escherichia coli (**E`H`EC**): `h`aemorrhagic --> **haemolytic uraemic syndrome** (HUS) = triad of **thrombocytopenia**, MAHA (**anaemia**) and **AKI**; caused by `Shiga toxin`-producing E.coli (STEC) 0157:H7
5. **Salmonella typhi**/ paratyphi: typhoid (/ paratyphoid) fever; faecal-oral route; **rose spots**, `constipation > diarrhoea`, multiplies in Peyer’s patches; Mx = **IV ceftriaxone** then PO azithromycin; complication = osteomyelitis in SCA
6. **Salmonella enteritides**: contaminated poultry, eggs (`BBQ`); non-bloody diarrhoea, abdominal pain that comes and goes in waves; self-limiting (or ceftriaxone if required)
NOTE: **vibrio** = `comma-shaped` bacteria
7. **Vibrio cholera**: comma-shaped bacteria; **enterotoxin** A + B; `rice water stool`, severe dehydration that leads to weight loss; Mx: self-limiting (or doxycycline if required)
8. **Vibrio parahaemolyticus**: comma-shaped bacteria; cruise ships / Japan = **undercooked / raw seafood**; ~3 days of diarrhoea; Mx: **doxycycline**
9. **Vibrio vulnificus**: comma-shaped bacteria; ; causes `cellulitis` in **shellfish handlers**; if PMH of **HIV** = can cause **sepsis**, D+V; Mx: **doxycycline**
10. **Campylobacter jejuni**: also **comma**-shaped bacteria gram -ve, oxidase +ve; `unpasteurised milk and poultry (mainly chicken)`; prodrome of headache and fever; watery **diarrhoea** that turns bloody; complication = **Guillain-Barre syndrome**; Mx = if in first 5 days, **erythromycin or ciprofloxacin**
11. Shigella: Shiga toxin (inactivates 60S ribosome) ; bloody diarrhoea w/pain; Mx = if not self-limiting then **ciprofloxacin**
12. **Yersinia enterocolitica**: faecal-oral route, Peyer’s patches, enterocolitis; complication = **reactive arthritis**
`NOTE: ALL gram -ve bacilli`
52
# SUMMARY CARD:
What are the protozoa that cause GI infections / diarrhoea?
1. **Entamoeba histolytica**: `dysentery` --> mobile trophozoite w/ **4 nuclei**, main RF = **MSM**; if trophozoites enter portal vein it causes **liver** `cyst/abscess` (anchovy paste appearance); `flask-shaped` **ulcer**; Mx = **metronidazole + paromomycin**
2. Giardia lamblia: **pear-shaped** trophozoite w/ **2 nuclei;** prolonged smelly, explosive non-bloody diarrhoea; biopsy = `partial villous atrophy`; Mx = **Metronidazole**
3. **Cryptosporidium parvum**: severe diarrhoea in `immunocompromised`; **Kinyoun acid-fast stain** w/oocytes in stool; Mx = **Paromomycin**
53
# SUMMARY CARD:
What are the viruses that can cause GI infection / diarrhoea?
1. **Rotavirus**: most **common** cause in `children`; w/ **fever + vomiting**, watery diarrhoea
2. **Norovirus**: G2.4 predominant strain; `lots of vomiting`; can cause outbreaks in adults
3. **Adenovirus**: infants (often immunocompromised); non-bloody diarrhoea
54
# DISEASE:
Which is the most common cause of viral gastroenteritis in children?
| schedule
Rotavirus
55
# DISEASE:
45F - **severe vomiting** after family gathering
sudden onset nausea + watery diarrhoea
which cause of viral gastroenteritis is this?
norovirus
56
# DISEASE:
Uni student
Had **canned beans** for mexican food night
`descending paralysis` (+ dysphagia + blurred vision)
microscopy: gram +ve bacilli
1. causative organism?
2. BONUS: Mx?
Clostridium botulinum --> botulism toxin
Mx = antitoxin
57
# DISEASE:
reheated leftover sunday roast
**watery diarrhoea** and cramps for the past 10 hrs
complains of passing `gas` that is very **foul smelling**
microscopy: gram +ve bacilli
1. causative organism?
2. BONUS: what are the RFs?
1. clostridium perfringens
2. RFs = **reheated meat**; incubation period of 8-16hrs, Sx lasts 24hrs
NOTE: foul smelling gas suggestive of `gas gangrene`
58
# DISEASE:
Severe diarrhoea
colonoscopy shows '**wet cornflakes appearance**'
`recently finished a course of abx`
microscopy: gram +ve bacilli
1. causative organism?
2. 4 C's that can lead to overgrowth of this bacterium
3. Mx?
1. clostridium difficile --> causes `pseudomembranous colitis` (looks like **wet cornflakes** on colonscopy)
NOTE: other complications include toxic megacolon
2. 4 C's = `c`ephalosporins, `c`lindamycin, `c`iprofloxacilin, `c`o-amoxiclav
3. IV **metronidazole** or oral **vancomycin**
59
# DISEASE:
Pt `reheated` leftover chinese takeaway
**4hrs** later, sudden vomiting + non-bloody diarrhoea
microscopy: gram +ve bacilli
1. causative organism?
**bacillus cereus** --> self-limiting
RF = `reheated rice`, incubation period ~4hrs
60
# DISEASE:
Pt went out for a meal and developed vomiting and water diarrhoea in **< 2 hours**
1. causative organism?
2. microscopy?
1. **staphylococcus aureus** --> short incubation period + self-limiting
2. gram +ve diplococci in `clusters`
61
# DISEASE:
**unpasteurised cheese** in pregnancy
D&V
microscopy: gram +ve bacilli w/ `tumbling motility`
1. causative organism?
2. Mx?
listeria monocytogenes
Mx = ampicillin, ceftriaxone, co-trimoxazole
62
# DISEASE:
traveller's diarrhoea
e.g. watery diarrhea, abdominal cramps, and low-grade fever after consuming street food in SE asia
1. causative organism?
ETEC (enterotoxigenic E. coli) --> gram -ve bacilli
63
# DISEASE:
2 y/o child has severe watery diarrhoea and vomiting after attending daycare
microscopy: gram -ve bacilli
1. causative organism?
| type of E coli
E`P`EC (enteropathogenic E. coli) = `p`aeds
64
# DISEASE:
6 y/o w/ **bloody diarrhoea**, abdominal pain and decreased urine output
Lab tests show `haemolytic anaemia + thrombocytopenia + AKI`
1. causative organism (+diagnosis)
haemolytic uraemic syndrome (**HUS**) --> caused by **EHEC** `0157:H7` (enterohemorrhagic Escherichia coli) which releases **Shiga toxin**
65
# DISEASE:
**constipation** > diarrhoea
`rose spots`
**splenomegaly**
1. causative organism (+ diagnosis)?
2. complications?
3. Mx?
| causes osteomyelitis in SCA pts
1. **salmonella typhi** (AKA typhoid fever)
2. osteomyelitis in SCA pts
3. IV ceftriaxone then PO azithromycin
66
# DISEASE:
Recent **BBQ** (contaminated poultry)
fever, vomiting, malaise, followed by diarrhoea
`abdominal pain that comes and goes in waves`
1. causative organism?
2. Mx?
1. Salmonella enterides
2. self-limited, resolves in ~3 days (or ceftriaxone if required)
67
# DISEASE:
**comma-shaped bacteria**
`rice water` stool + **weight loss** (due to dehydration)
1. causative organism?
2. toxins?
3. Mx?
1. Vibrio cholera
2. enterotoxins A + B
3. self-limiting (if not doxycycline)
| NOTE: all vibrios are comma shaped
68
# DISEASE:
cruise ships / Japan = **undercooked / raw seafood**
~3 days of diarrhoea
1. causative organism?
2. Mx?
1. vibrio parahaemolyticus
2. doxycycline
69
# DISEASE:
Initially presented with `cellulitis`
As HIV +ve, quickly progressed to sepsis
Works as a **shellfish handlers**
1. causative organism?
2. Mx?
1. Vibrio vulnificus
2. Doxycycline
70
# DISEASE:
`Unpasteurised meat / milk products (esp. chickens)`
**bloody diarrhoea**, foul smelling
bloating + cramps
microscopy: S / comma shaped, **gram -ve, oxidase +ve**
1. causative organism?
2. complication?
3. Mx?
1. Campylobacter jejuni
2. complication = **Guillain-Barre syndrome**
3. Mx = if in first 5 days, **erythromycin or ciprofloxacin**
71
# DISEASE:
**abdominal pain and watery diarrhoea** after consuming undercooked pork
**Peyer's patches** in terminal ileum
`Complications = reactive arthritis`
1. causative organism?
Yersinia enterocolitica
72
# DISEASE:
`dysentry, flatulence, tenesmus`
**MSM**
microscopy = mobile trophozoite w/ **4 nuclei**,
**liver** `cyst/abscess` (anchovy paste appearance on USS)
`flask-shaped` **ulcer**
1. causative organism?
2. Mx?
1. Entamoeba histolytica (protozoa)
2. Mx = **metronidazole + paromomycin**
73
# DISEASE:
**pear-shaped** trophozoite w/ **2 nuclei**
flatulence, prolonged smelly, explosive non-bloody diarrhoea
RFs: travellers, MSM, campers, hikers
biopsy = `partial villous atrophy`
1. causative organism?
2. Mx?
1. giardia lamblia (protozoa)
2. Mx = oral **Metronidazole**
74
# DISEASE:
severe diarrhoea in `immunocompromised`
`oocytes` seen in stool w/ **Kinyoun acid-fast stain**
1. causative organism?
2. Mx?
1. Cryptosporidium parvum (protozoa)
2. Mx = **Paromomycin**
75
# SUMMARY CARD:
What are the different ways to classify UTIs?
Ix?
| complicated vs uncomplicated; lower vs upper
**Uncomplicated** = women
**Complicated** = `men`, `catheters`, `pregnancy`, functionally / structurally abnormal tract
**Lower** = affects only the `bladder`
**Upper** = affects `kidneys`, systemically unwell
* **Urinalysis** (not typically done in men, women > 65 y/o or catheterised): shows `↑` `nitrites` (specific for UTI) and ↑ leukocytes (founnd in any inflammatory condition of the urinary tract)
* **Urine culture**: >10^4 colony forming units / ml = `diagnostic` (note: mixed growth or squamous cells suggests contaminated sample)
NOTE: >10^3 colony forming units / ml is used for E. coli and S. saprophyticus
76
# SUMMARY CARD:
What is the management of UTIs?
1. Uncomplicated?
2. Complicated?
3. Pyelonephritis?
4. Pregnancy?
5. Catheter-associated?
BONUS: what is trimethoprim CI against?
1. **Uncomplicated**: `nitrofurantoin` (or trimethoprim) for `3` days
2. **Complicated** (e.g. male or previous Hx w/resistant organisms): `nitrofurantoin` (or trimethoprim / cefalexin) for `7` days
3. **Pyelonephritis**: admit + `IV co-amoxiclav` / amikacin / cefalexin
4. **Pregnancy**: `nitrofurantoin` (but congenital malformations at 3rd trimester), at term = `co-amoxiclav/cefalexin`/trimethoprim
NOTE: **nitrofurantoin** can increase the risk of `haemolytic anaemia in newborn` if administered close to term; and **trimethoprim** (`folate antagonist`) can cause neural tube defects if administered in the `first trimester`
5. **Catheter**-associated: `remove catheter` + aminoglycoside (e.g. `gentamicin`) **OR** if `candida`, then no antifungal unless awaiting renal transplant (then oral fluconazole)
BONUS: **trimethoprim is a folate antagonist**, therefore it is NOT prescribed if pt is on `methotrexate`!
77
# SUMMARY CARD:
What are the different organisms that can cause UTIs and their features?
Hint: 3 gram +ve, 4 gram -ve, 1 fungus
| 3 staph, E.coli, klebsiella, enterobacter, proteus mirabilis, candida
1. `Escherichia coli` (**most common**) = `lactose fermenting` gram -ve bacilli; classically **young women** who are `sexually active`);
2. `Staphylococcus saprophyticus` = gram +ve cocci in clusters; **2nd most common** in young women; `catalase +ve, coagulase -ve`; associated with catheters; has **p-fimbriae** (a protein) that allows adherence to the urinary tract
3. `Staphylococcus aureus` = gram +ve cocci in clusters; `catalase +ve, coagulase +ve`; most common cause of **haematogenous spread** so take blood cultures as likely to have bacteraemia
4. `Staphylococcus epidermidis` = gram +ve cocci; indwelling catheter; catalase +ve, coagulase -ve
5. `Proteus mirabilis` = gram -ve bacilli; associated with **kidney stones** --> struvite stones (`staghorn` calculi), **young boys**
NOTE: this is because proteus mirabilis produce urease, which converts ammonia to urea, which leads to alkaline urine pH and struvite crystals
6. `Klebsiella` = `lactose fermenting` gram -ve bacilli; associated w/ **immunocompromised + indwelling catheter**
7. `Enterobacter` = `lactose fermenting` gram -ve bacilli; associated w/ **immunocompromised**
8. `Candida albicans` = fungus; **catheter-associated**
78
# DISEASE:
Which 3 UTI organisms are lactose fermenting?
1. E. coli
2. Klebsiella
3. Enterobacter
79
# DISEASE:
`sexually active` **young woman** w/ **dysuria** + frequency
urine dip: haematuria ++, **nitrites** ++
1. causative organism?
2. microscopy?
1. E. coli
2. gram -ve bacilli (lactose fermenting)
80
# DISEASE:
**young women** w/ **dysuria** + frequency
urine dip: haematuria ++, `nitrites` ++
microscopy: gram +ve cocci
1. causative organism?
2. BONUS: coagulase & catalase?
3. Mx?
Staphylococcus saprophyticus
catalase +ve, coagulase -ve
Mx = 3 days nitrofurantoin
81
# DISEASE:
`young boy`
suprapubic tenderness, dysuria, foul smelling urine
`alkaline urine pH`
1. causative organism?
2. complication?
1. `proteus mirabilis` (-ve bacilli)
2. proteus mirabilis produces urease --> converts ammonia to urea, which leads to alkaline urine pH and **struvite crystals** (kidney stones - AKA staghorn calculi)
82
# DISEASE:
Elderly pt w/ **long-standing `catheter`**
signs of confusion / delirium
microscopy: **budding yeast cells**
1. causative organism?
2. Mx?
1. candida albicans
2. remove catheter, no Mx unless pt awaiting renal transplant (then oral fluconazole)
83
# DISEASE:
`immunocompromised` pt w/ `catheter`
suprapubic tenderness, cloudy urine
microscopy = **lactose fermenting gram -ve bacilli**
1. causative organism?
Klebsiella
NOTE: enterobacter also lactose fermenting gram -ve bacilli found in immunocompromised pts (not associated with catheters though)
84
# DISEASE:
30 y/o **man** with suprapubic tenderness, haematuria + dysuria
blood cultures: `bacteraemia`
microscopy: `gram +ve cocci, catalase +ve, coagulase +ve`
1. causative organism?
2. Mx?
1. Staph aureus
2. 7 days nitrofurantoin (because men = complicated = longer abx duration)
85
# DISEASE:
State the most likely causative organisms, RFs and Mx of the following wound / bone / joint infections:
1. Septic arthritis
2. Osteomyelitis
3. Prosthetic joint infection
4. Surgical site infection
1. **Septic arthritis**: `neisseria gonorrhoea` in young pts; `staphylococcus aureus`> strep > E. coli in older pts
* RFs: pre-existing arthritis, diabetes, CKD, liver failure
* S&S: pyrexia, swollen joint (knee most likely affected), red, hot and reduced movement
* Ix: joint aspirate
* Mx: drain joint + `IV cefotaxime` for N. gon; `IV fluclox` for staph
2. **Osteomyelitis**: `staphylococcus aureus`, or `salmonella if SCA`, or `pseudomonas if IVDU`
* S&S: lumbar most affected region = vertebral pain,
* Mx = `IV fluclox` for staph aureus, `IV piperacillin` for pseudomonas cover
* Radical debridement if chronic osteomyelitis
3. **Prosthetic joint infection**: `CoNS` (coagulase-negative staphylococci) e.g. staph `epidermis`
* Signs same as septic arthritis
* Radiology would show **loosening of the bone**
* Mx: remove prosthesis + `IV vancomycin` and `oral rifampicin`
4. **Surgical site infection**: `staph aureus` > E. col > strep
* 2nd most common HAI
* Mx = oral/IV `flucloxacillin` OR if (suspected) MRSA = IV `vancomycin/linezolid`
86
# DISEASE:
`28 y/o` sexually active man
severe **pain** and **swelling** in L `knee` joint + low-grade **fever**
Joint aspiration = **purulent** fluid
1. diagnosis + causative organism?
2. Mx?
Septic arthritis --> due to **Neisseria gonorrhoea** (gram -ve diplococci)
Mx = drain joint + `IV cefotaxime`
87
# DISEASE:
50 y/o man w/ poorly controlled **diabetes**
`Chronic lower back pain` + difficulty walking for past month
**Tenderness** over the lumbar spine + limited ROM. X-ray = **periosteal thickening** + bone destruction
1. diagnosis + causative organism?
2. Mx?
1. osteomyelitis (lumbar region most commonly affected) --> **staph aureus** = most common causative organism
2. Mx = `IV flucloxacillin`; chronic osteomyelitis = surgical debridement
88
# DISEASE:
1. osteomyelitis in SCA --> causative organism?
2. osteomyelitis in IVDU --> causative organism?
1. **salmonella typhi**
2. **pseudomonas aureginosa**
89
# DISEASE:
65F w/ PMHx of RA has worsening **pain + swelling** of R hip joint, where she had a `total hip replacement` 6 months ago
Imaging = `loosening of the prosthetic` components
1. diagnosis + causative organism?
2. Mx?
1. prosthetic joint infection --> **staphylococcus epidermis** (or other CoNS = coagulase neg staph)
2. remove prosthesis + `IV vancomycin` and `oral rifampicin`
90
# DISEASE:
45M - underwent elective abdo surgery for hernia repair
2 days post-op, develops increasing redness, warmth, and purulent discharge at the surgical incision site
1. diagnosis + causative organism?
2. Mx?
1. surgical site infection --> **staph aureus**
2. IV `flucloxacillin`
91
# SUMMARY CARD:
What is the difference between meningitis & encephalitis?
| definition, S&S
**Meningitis** = inflammation of `meninges`
* S&S = **meningism** e.g. stiff neck, photophobia, headache
* Ix = LP > abx; gram stain for bacteria, PCR for virus, India ink stain for cryptococcus, ZN stain for TB
VS
**Encephalitis** = inflammation of the `brain parenchyma`
* S&S = meningism + **altered mental status** e.g. confusion, fluctuating consiousness
92
# SUMMARY CARD:
Causative organisms for meningitis?
| bacterial, viral, fungal, TB
**1. Bacterial**: CSF = **very high** `neutrophils`, high protein, low glucose
* **Neisseria meningitidis** (gram `-ve`), **streptococcus pneumoniae** (gram `+ve`)
* **Ix = gram stain**
* Neonates: GBS, listeria monocytogenes, E. coli
* Elderly: GBS, listeria monocytogenes
* `RFs for N. meningitidis` = complement deficiency, hyposplenism (NHS), hypogammaglobulinaemia
* `RFs for strep. pneumoniae` = complement deficiency, hyposplenism (NHS), immunosuppressed (alcoholic), infection (pneumonia), previous head trauma w/ CSF leak
* Mx = `IV ceftriaxone + corticosteroids` (+ listeria cover for neonates / elderly w/ **ampicillin**)
**2. Viral:** CSF = **very high** `lymphocytes`, high protein, normal glucose
* `Enteroviruses` e.g. coxsackie, echovirus
* Mumps
* `HSV2`
* **Ix = PCR**
**3. Fungal:**
* Cryptococcus neoformans (chronic) --> **India ink stain**
**4. TB:** CSF = high `lymphocytes`, `VERY HIGH protein`, low glucose
* CHRONIC meningitis
* **Ix = Ziehl-Neelson stain**
* Mx: Dexamethasone w/anti-TB drugs
* MRI: **leptomeningeal enhancement**
93
# SUMMARY CARD:
Causative organism for encephalitis?
| BONUS: Ix + Mx?
Most commonly caused by `HSV 1`
Ix = temporal + inferior frontal lobes affected
Mx = **IV aciclovir**
94
# SUMMARY CARD:
Causative organisms and S&S of the following CNS infections:
1. myelitis
2. tetanus
3. brain abscess
| HINT: 1. paralysis; 2. tetanospasmin; 3. TRIAD
1. **Myelitis**: `poliovirus`; Sx = `paralysis` w/ preceding muscle fasciculations
2. **Tetanus**: `clostridium tetani`; RFs = IVDU; `tetanospasmin` prevents GABA + glycine release, which leads to **rigid spastic paralysis**, lockjaw (trismus), opisthotonos (arched back); Mx = `metronidazole`
3. **Brain abscess**: staph / strep; **TRIAD**: `headache` (dull, persistent), `swinging fever` + `focal neurology` (due to space occupying lesion); Ix = **ring-enhancing lesion**; Mx = **craniotomy** w/ `IV ceftriaxone + metronidazole`
95
# SUMMARY CARD:
What is prion disease and what are the 3 different types?
| sporadic (demented LAMB), genetic (2 types), acquired (moo)
**1. Sporadic**: codon 129 – MM polymorphism
* Demented `LAMB` =`l`ower motor neuron signs, `a`kinetic mutism, `m`yoclonic jerks and cortical `b`lindness)
* EEG = periodic **triphasic** sharp wave complexes
* LP = 14-3-3 + S100 **protein**
* Autopsy= spongiform vacuolation, `PrP` **amyloid plaques**
**2. Genetic**: PRNP P102L (GSS syndrome)/PRNP D178N (FFI) --> **TWO** types:
* **Gerstmann-Strausslet-Sheinker** syndrome: ADD = slowly progressive `a`taxia, `d`iminished reflexes, `d`ementia
* **Familial fatal insomnia**: `untreatable insomnia` (agrypnia excitata), dysautonomia, late cognitive decline, die from lack of sleep
**3. Acquired:** variant – Bohvine-Johne’s Disease in cows (`Mad Cow Disease`)
* Young patients
* `Psychiatric Sx` e.g. anxiety, paranoia and hallucinations, then dementia
* Ix: `tonsillar biopsy` (gold-standard), **pulvinar** sign (**nuclei in thalamus**)
* Autopsy = **florid plaques**
96
# SUMMARY CARD:
CSF analysis for the different causative organisms of meningitis:
1. appearance
2. glucose
3. white cells
4. cell type
5. other
| bacterial, partially treated bacterial, viral, TB
* **`Bacterial`**: turbid CSF, LOW glucose, HIGH WCC (polymorphs AKA `neutrophils`)
* **Partially treated** `bacterial`: turbid CSF, **NORMAL glucose**, HIGH WCC (polymorphs AKA `neutrophils`)
* **Viral**: `clear` CSF, NORMAL glucose, HIGH WCC (mononuclear AKA `lymphocytes`)
* **TB**: clear or turbid CSF, `VERY LOW glucose`, HIGH WCC (mononuclear AKA **lymphocytes**)
97
# DISEASE:
`2 month` infant w/ **fever**, **irritability**, **poor feeding**, and lethargy
LP = turbid, ↓ glucose, `↑ neutrophils`
1. diagnosis + possible causative organisms?
2. Mx?
BONUS: what test is done to identify the organism?
1. **bacterial meningitis** (due to `↑ neutrophils` in CSF) --> `< 3 months` so could be neisseria meningitidis, streptococcus pneumoniae OR listeria
2. Mx = `IV ceftriaxone AND ampicillin` (for **listeria** cover)
BONUS: gram stain for bacterial causes
## Footnote
meow
98
# DISEASE:
**Unvaccinated** child
recently recovered for `parotitis` (inflammed parotid glands)
S&S now = fever, headache, photophobia, lethargy
Kernig's sign +ve
CSF: lymphocytic pleocytosis (aka `↑ lymphocytes`)
1. diagnosis + causative organism?
2. Ix?
2. Mx?
1. `viral meningitis` (due to`↑ lymphocytes` in CSF) --> most likely due to **mumps** virus (unvaccinated, **parotitis**)
2. Ix = `IgM mumps detection`
3. Mx = supportive usually for viral
NOTE: could give IV aciclovir if herpes cause
99
# DISEASE:
22F went to subsaharan `africa` with friends 3 weeks ago
Cough + **haemoptysis**
Now S&S = fever, +ve Kernig's sign, headache, photophobia
CSF = clear, `↓↓↓ glucose, ↑ lymphocytes`
1. diagnosis + causative organism?
2. Ix?
3. Mx?
1. TB meningitis --> mycobacterium tuberculosis (due to `↓↓↓ glucose, ↑ lymphocytes`)
2. Ziehl-Neelson = stain carbol fuschin & methylene blue --> AFB go `red` on a blue background
3. Mx = **dexamethasone w/ anti-TB drugs**
100
# DISEASE:
45M - 3/7 seizures, confusion, fever, photophobia
MRI: temporal + inferior frontal lobe involvement
1. diagnosis + causative organism?
2. Mx?
1. encephalitis --> HSV1 (most common)
2. IV aciclovir
101
# DISEASE:
4M - travelled to Afghanistan 2 weeks ago
`Not immunised`
Sensitivity to touch, `muscle spasms` --> progressed to `paralysis`
1. most likely diagnosis + causative organism?
BONUS: when are kids vaccinated for this virus usually?
**(polio)myelitis** --> `poliovirus`
Normally, IPV (inactive polio vaccine) given as a part of 6 in 1 (2, 3, 4 months), 4 in 1 (3yrs + 4months), and 3 in 1 (14 years)
102
# DISEASE:
30M - recent puncture **wound** in foot
IVDU
`Severe muscle spasms` + `jaw stiffness` (unable to open mouth)
Arched back (`opisthotonos`)
1. diagnosis + causative organism?
2. Mx?
1. Tetanus --> `clostridium tetani`
2. Mx = metronidazole
103
# DISEASE:
50M - 1/12 hx of `dull persistent headache` + `intermittent fever` + `weakness in right arm & leg`
1. diagnosis + causative organism?
2. Ix?
3. Mx?
| Ix - what is seen on brain MRI / CT?
1. Brain abscess --> strep or staph
2. Brain MRI = ring-enhancing lesion
3. Mx = **craniotomy** w/ `IV ceftriaxone + metronidazole`
104
# DISEASE:
65M - `rapidly progressive dementia` (increasingly forgetful, struggling to speak)
blindness w/ normal pupillary reflexes to light
myoclonic jerks
decreased reflexes
1. most likely diagnosis?
2. What is seen on EEG / LP / autopsy?
| EEG = tri; LP = protein; autopsy = plaques
**1. Sporadic prion disease**
NOTE: Sx = demented `LAMB` =`l`ower motor neuron signs, `a`kinetic mutism, `m`yoclonic jerks and cortical `b`lindness)
NOTE: cortical blindness is loss of vision w/o opthalmologic cause and preserved pupillary light reflexes
2. EEG = periodic **triphasic** sharp wave complexes; LP = 14-3-3 + S100 **protein**; autopsy = spongiform vacuolation, `PrP` **amyloid plaques**
105
# DISEASE:
42f - `a`taxia, `d`iminished reflexes, and cognitive decline (`d`ementia) over the past year
FHx of progressive neurological symptoms
1. diagnosis?
Genetic Gerstmann-Strausslet-Sheinker (one of the genetic prion diseases)
106
# DISEASE:
55F - 3/12 hx of **worsening insomnia**
Tried relaxation therapies, melatonin tablets, no screen time 4 hours before bed etc.
**FHx** of this leading to madness --> death
Genetic testing: `PRNP D178N mutation`
1. diagnosis?
Familial fatal insomnia (**UNTREATABLE** `insomnia`)
107
# DISEASE:
30M - worsening `anxiety`, `paranoia`, + auditory & visual `hallucinations`
Exhibits **cognitive decline**
HPC: consumed **beef** products
1. diagnosis?
2. Ix - gold standard?
3. Autopsy?
1. variant of Bohvine-Johne’s Disease AKA `Mad Cow Disease` (**acquired prion disease**)
2. `Tonsillar biopsy` --> abnormal prions (gold standard)
note: can also do MR --> pulvinar sign (nuclei in thalamus)
3. Autopsy = **florid plaques**
108
# SUMMARY CARD:
Name possible STIs based on presentation:
1. Discharge
2. Ulceration
3. Rashes, lumps/growths
1. **Discharge**: gonorrhoea, chlamydia, trichomonas, candida, BV
2. **Ulceration**: syphilis (`painless` chancre), chancroid, LGV, donovanosis
3. **Rashes, lumps/growths**: genital warts (HPV `6 & 11`), molluscum contagiosum, scabies, pubic lice
109
# SUMMARY CARD:
Name the causative organisms (+ Sx / Ix / Mx) of the following bacterial STIs:
1. Gonorrhoea
2. Genital chlamydia
3. Lympho-granuloma venereum
4. Syphilis
5. Chancroid
6. Donovanosis
7. Bacterial vaginosis
**1. Gonorrhoea** --> `neisseria gonorrhoea` (gram **-ve** cocci)
* Urethritis / cervicitis, discharge, dysuria (rectal prostitis if MSM)
* Mx = `ceftriaxone`
**2. Genital chlamydia** --> `chlamydia trachomatis` (-ve coccobacilli)
* Often **asymptomatic** (esp. in women, so 1st presentation may be PID / infertility)
* Yellow / green `discharge`
* **Serovars D-K** cause genital chlamydia
* `NAAT` (nucleic acid amplification test) from genital swabs / first void urine confirms diagnosis
* Mx = `doxycycline` 100mg BD 7 days OR 1g `azithromycin` stat (e.g. in pregnancy because doxy is teratogenic)
**3. Lympho-granuloma venereum** --> `chlamydia trachomatis` (-ve coccobacilli) causes **lymphatic** infection
* **Serovars L1, L2 and L3**
* `3 stages`: painless ulcer/papule on genitals; then painful inguinal lymphadenopathy; then proctocolitis
* Dx = +ve urinary `NAAT`
* Mx = **doxycycline**
**4. Syphilis** --> `treponema pallidum` (-ve spirochaete)
* 1° = `PAINLESS ULCER` (**chancre**)
* 2° = widespread rash + **”snail track” ulcers** + condyloma acuminate (genital warts, hypopigmented lesions)
* 3° = **THREE** different syndromes: `gumma` (gum-like pus lesion); `CVS` e.g. ascending aortic aneurysm (**AAA**), `neurosyphilis` e.g. arygyll-Robertson pupil + dementia + tabes dorsalis (spinal cord)
* `Spirochaetes` in CSF in 3° syphilis
* Ix = **dark-field microscopy** (for 1° chancre) shows treponemes
* Treponemal = detects Abs against specific antigens which stays +ve long term even after Tx VS non-treponemal tests = detects Abs against non-specific antigens and titres fall w/ effective Tx
* Mx = `benzathine benzylpenicillin IM` (doxy if allergic) – monitor with RPR titres + can cause **Jarisch-Herxheimer** reaction (rash, hypotension, fever)
**5. Chancroid** --> `haemophilus ducreyi` (-ve coccobacilli)
* `PAINFUL` ulcer
* unilateral painful inguinal lymphadenopathy
* Ix = chocolate agar
**6. Donovanosis** --> `klebsiella granulomatis` (-ve bacilli)
* **Beefy** `red` **ulcers**
* Ix = `Giemsa stain` --> **donavan bodies**
* Mx = `azithromycin`
**7. Bacterial vaginosis** --> `gardnerella vaginalis` (gram variable)
* Smelly white creamy `discharge`
* Ix: **Amsel criteria** (clue cells, pH >4.5, whiff test, abnormal vaginal discharge)
* Mx: `metronidazole` (even in pregnancy)
110
# SUMMARY CARD:
Name the causative organisms (+ Sx / Ix / Mx) of the following STIs:
1. Trichomoniasis
2. Candidiasis
3. Molluscum contagiosum
4. Genital warts
5. Examples of viral STIs
**1. Trichomoniasis** --> `trichomonas vaginalis` (flagellated protozoa)
* Men = asymptomatic usually (?urethritis); women = **yellow/green discharge**, offensive smelling
* pH >4.5 (NOTE: BV is the only other condition w/ pH >4.5 asw)
* Ix = speculum --> `strawberry cervix`
* Ix = wet slide microscopy (**motile trophozoites**)
* Mx = `metronidazole`
* Associated w/ ↑ risk of HIV due to disrupted mucosa
**2. Candidiasis**/ thrush --> `candida albicans` (yeast)
* '`Cottage cheese`' (thick white) discharge
* Mx = oral **fluconazole** (BUT cream / pessaries ONLY if pregnant, oral contraindicated)
**3. Molluscum contagiosum** --> `poxvirus`
* `Small papules w/ central punctum` (widespread if immunocompromised)
* Children: spread by skin-to-skin contact, spots on hands & face
* Adults: spread via sexual contact, genital lesions
* Supportive Mx / cryotherapy if persistent
**4. Genital warts** --> HPV 6 & 11
* Mx = **podophyllotoxin** solution / cream (CI pregnancy); 2nd line = cryotherapy in clinic or Imiquimod
**5. Examples of viral STIs:**
* Hepatitis, HBV, HCV (mainly in HIV +ve MSM), herpes, HIV
111
# DISEASE:
**Unprotected** intercourse w/ multiple partners
`purulent yellow/green discharge` from urethra
NAAT = gram **-ve cocci**
1. diagnosis + causative organism?
2. Mx?
1. **Gonorrhoea** (due to `neisseria gonorhoea`)
2. Mx = `ceftriaxone`
112
# DISEASE:
33F - recently changed partners
lower abdo pain + **greyish white** vaginal discharge
`cervical excitation` on bimanual
1. diagnosis + causative organism?
BONUS: gram stain of organism?
2. Mx?
1. **PID** (due to `chlamydia trachomatis`)
BONUS: gram -ve coccobacilli
2. `Doxycycline` 100mg BD 7 days (azithromycin 1g stat if pregnant)
113
# DISEASE:
Started off as **painless ulcers** on genitals, then developed painful **inguinal lymphadenopathy**
Now **rectal discomfort** --> inflammation of the anus & colonic mucosa (`proctocolitis`)
1. diagnosis + causative organism?
2. which specific serovars of the organism cause this?
3. Mx?
1. Lymphogranuloma venereum - **LGV** (due to `chlamydia trachomatis`) = infection in lymphatic system
2. Serovars **L1-L3**
3. `Doxycycline` 100mg BD 3 wks
114
# DISEASE:
15 years ago had painless genital ulcers (`chancre`) + **rashes** on palms + hypopigmental lesions (**condyloma acuminate**)
Now, `tabes dorsalis + gum-like pus lesion + aortic root dilation`
1. diagnosis + causative organism?
2. Ix?
3. Mx?
1. currently has **3° syphilis** (due to `treponema pallidum`)
NOTE: Sx from 15 years ago are 1° + 2°
Currently pt has gumma (gum-like pus lesion) + spinal cord involvement (tabes dorsalis) + CVS involvement (AAA) = 3°
2. Ix = **dark-ground** microscopy to see chancre (treponemes seen)
for 3°, Ix = **non-treponemal test** (tests for Abs against non-specific antigens as the titres go down after Tx)
NOTE: treponemal test looks for Abs against specific antigens and this stays +ve for many years even after successful Tx
3. **Mx** = `single dose IM benpen` (benzathine benzylpenicillin
115
# DISEASE:
32M - PMHx = syphilis, comes in for follow-up **after** initiating treatment with `benzathine benzylpenicillin`
Now has **fever**, chills, headache, + myalgia
**low BP**
1. what is this reaction called?
| JH
**Jarisch-Herxheimer reaction**
116
# DISEASE:
`painful` **genital ulcer**
painful R sided (**unilateral**) **inguinal lymphadenopathy**
1. diagnosis + causative organism?
2. what type of agar is it cultured on?
| makes you cry; nom nom nom
1. **chancroid** (due to `haemophilus ducreyi` = -ve coccobacilli)
2. **chocolate** agar
117
# DISEASE:
**beefy** `red` **ulcers**
Giemsa staining of ulcer swabs reveals `Donovan bodies`; **-ve bacilli**
1. diagnosis + causative organism?
2. Mx?
1. **Donovanosis** (due to `klebsiella granulomatis`)
2. Azithromycin
118
# DISEASE:
`smelly` **white** creamy discharge after using fem hygiene soaps to clean the vagina
1. diagnosis + causative organism?
2. Ix?
3. Mx?
| cinderalla got this; criteria?
1. **Bacterial vaginosis** (due to `gardnerella vaginalis`)
2. **Amsel criteria**: clue cells, pH >4.5, whiff test, abnormal vaginal discharge
3. Mx: `metronidazole` (even in pregnancy)
119
# DISEASE:
**yellow/green discharge**
`strawberry cervix`
1. diagnosis + causative organism?
2. Ix?
3. Mx?
BONUS: associated with increased risk of which infection?
1. Trichomoniasis (due to`trichomonas vaginalis`, a flagellated protozoa)
2. Ix = wet slide microscopy --> **motile trophozoites**
3. Mx = `metronidazole`
BONUS: associated w/ ↑ risk of HIV due to disrupted mucosa
120
# DISEASE:
`cottage cheese` thick white discharge after starting fem hygiene soaps
`pruritic` vulva / vagina (**vulvovaginitis**)
1. diagnosis + causative organism?
2. Mx?
1. **candidiasis** (due to `candida albicans`, yeast)
2. oral `fluconazole` (unless pregnant, then pessary / topical)
121
# DISEASE:
`Small papules w/ central punctum`
not itchy, apyrexial
widespread if immunocompromised
1. diagnosis + causative organism?
2. Mx?
1. molluscum contagiosum
2. supportive Mx (cryotherapy if persistent)
122
# DISEASE:
25F = missed her HPV vaccine in secondary school
new sexual partner last month
**painful genital lesions**
1. diagnosis + causative organism(s)?
2. Mx?
* **Genital warts** (caused by `HPV 6 & 11`, which are normally in the HPV vaccine given at 13 years)
NOTE: oncogenic types are HPV 16 and 18
* Mx = **podophyllotoxin** solution / cream (CI pregnancy); 2nd line = cryotherapy in clinic or Imiquimod
123
# SUMMARY CARD:
What are the causative organisms of each of the following zoonoses:
1. Malaria
2. Typhoid
3. Dengue
4. Spotty rocky mountain fever
5. Rabies
6. Q fever
7. Brucellosis
8. Leptospirosis
9. Lyme disease
10. Human plague
11. Anthrax
12. Leishmaniasis
13. Sleeping sickness
14. Catch scratch disease
1. **Malaria**: `malariae falciparum` (most common), vivax, ovale, knowlesi, malariae
2. **Typhoid**: `salmonella typhi` = gram -ve bacilli
3. **Dengue**: `flavivirus`
4. **Spotty rocky mountain fever**: `rickettsial akari` = gram -ve coccobacilli
5. **Rabies**: `rhabdovirus`
6. **Q fever**: `coxiella burnetti` (BBQ --> CBQ --> house of CB --> coxiella burnetti) = gram -ve coccobacilli
7. **Brucellosis**: `brucella miletensis` = gram -ve coccobacilli
8. **Leptospirosis**: `leptospira interrogans` = gram -ve spirochete
9. **Lyme disease**: `borrelia burgdorferi` = gram -ve spirochete (Avril lavigne --> babiest baby --> BB --> borrelia burgdorferi)
10. **Human plague**: `yersinia pestis` = gram -ve bacilli (yessir pestis)
11. **Anthrax**: `bacillus anthrax` that release a tripartite protein toxin = gram +ve rods
12. **Leishmaniasis**: `leishmania major`/tropica (most common); donovani (Kala Azar)
13. **Sleeping sickness**: `trypanosoma` brucei and Trypanosoma cruzi (Chagas)
14. **Catch scratch disease**: `bartonella henselae` = gram -ve bacilli (cats? chickens? henselae)
124
# SUMMARY CARD:
* What are the features of **malaria**?
* How does it spread (vector)?
* How is it diagnosed and managed?
* BONUS: what fever is a complication of malaria falciparum?
* **Plasmodium falciparum**, vivax, ovale, knowlesi, malariae
* `Female anopheles mosquito`
* Endemic regions / recent travel (PUO in returning traveller from endemic region)
* *TIP: Ask if pt took `malaria prophylaxis`*
* **Cyclical fevers** (every 48 hrs in falciparum/vivax/ovale and 72 hrs in malariae)
* NOTE: can also get cerebral malaria --> leads to coma
* Sx of severe falciparum malaria = impaired conscious / seizures, renal impairment, acidosis, hypoglycaemia, pulmonary oedema, anaemia, DIC, shock, haemoglobinuria (without G6PDD)
* NOTE: HLA-B53 is protective against severe malaria
* Thick and thin `blood films` = 3x **thick** (to check for parasites) and **thin** (to quantify parasitaemia + demostrate the species; if `>2%` in children or `>10%` in adults --> severe)
* **Falciparum** = `Maurer’s clefts` in RBCs
* Ovale + Vivax = Schuffner dots in RBCs
* **Mx** for Falciparum = `oral malarone / IV artesunate` (if severe)
* Mx for Ovales + Vivax + Malariae = chloroquine
* NOTE: antimalarials can cause acute haemolysis in people with G6PDD
BONUS: **blackwater fever** severe complication of plasmodium falciparum malaria characterised by `haemoglobinuria` (AKA dark urine --> 'blackwater')
125
# SUMMARY CARD:
* What are the features of **typhoid fever**?
* How does it spread?
* How is it diagnosed and managed?
* BONUS: can you vaccinate against this?
* **Salmonella typhi** (or paratyphi) = gram -ve bacilli
* Faeco-oral spread (**contaminated food** / water) - 1-2 wks incubation
* `Enteric fever` (fever + GI Sx) --> due to Peyer's patches
* High prolonged fever + headache
* `Constipation` > diarrhoea
* **Rose spots**
* **Relative bradycardia** (AKA Faget sign) --> with high temperature you expect ↑HR, but pt actually has normal HR
* GOLD STANDARD = **blood culture** (+/- stool culture)
* **Mx** = `IV ceftriaxone, then PO azithromycin`
BONUS: typhoid vaccine vaccinates against S. typhi
126
# SUMMARY CARD:
* What are the features of **dengue**?
* How does it spread?
* How is it diagnosed and managed?
* BONUS: what other types of dengue can you get?
* **Flavivirus**
* `Female aedes mosquito` - short incubation period (days)
* SE asia, urban environments
* NOTE: **rare in travellers** (unlike malaria) as uncommon to be re-infected
* Sx: **fever**, **myalgia**, sunburn rash, retroorbital **headache**
* Fever then fucked (critical) before recovery
* Ix = ↓Hb, ↓WCC, ↓platelets
* **Councilman bodies** (inclusion bodies) in hepatocytes
* **Supportive Mx**
**BONUS**: dengue haemorrhagic fever = ↑ bleeding; dengue shock syndrome = ↓ BP
127
# SUMMARY CARD:
* What are the features of ** Rocky Mountain spotted fever**?
* How does it spread?
* How is it diagnosed and managed?
* **Rickettsial akari** - gram negative coccobacilli
* Liponyssoides sanguineus (`tick`)
* Fever + headache + `rash` that starts peripherally (maculopapular to vasculitic)
* Myalgia
* **Black eschars**
* **Mx** = `doxycycline`
128
# SUMMARY CARD:
* What are the features of **rabies**?
* How does it spread?
* How is it diagnosed and managed?
BONUS: what is found in the infected neurons?
* Lyssa virus / **rhabdovirus**
* `Dogs` or bats
* **Prodrome**: fever + headache + sore throat
* `Migration to CNS` (after months - years) = **hypersalivation**, **hydrophobia**, acute **encephalitis** (agitation, seizure)
* NOTE: nearly 100% mortality once CNS Sx
* Therefore, MUST take prophylactic rabies vaccine! --> `rabies IgG post-exposure vaccination course`
* **Ix = IgM**
**BONUS**: `negri bodies` in infected neurons
| rabies = rhabovirus
129
# SUMMARY CARD:
* What are the features of **Q fever**?
* How does it spread?
* How is it diagnosed and managed?
BONUS: what is found in the infected neurons?
| house of CB
* **Coxiella burnetti** = gram -ve coccobacilli
* `Cattle / sheep`
* Fever
* **Atypical pneumonia** (dry cough) or endocarditis
* CXR = `ground-glass` appearance
* Ix = serology
* **Mx** = `doxycycline`
130
# SUMMARY CARD:
* What are the features of **brucellosis**?
* How does it spread?
* How is it diagnosed and managed?
BONUS: what are the complications (HINT: MEOw)?
| anti-O-polysaccharide antibody
* **Brucella melitensis** = gram -ve bacilli
* `Unpasteurised dairy, direct animal contact` (farmers)
* **SUDDEN** onset ↑ fever
* Returning traveller with **orchitis** + back pain (sacroiliitis) with psoas + liver **abscesses**
* **Brucella serology**: `anti-O-polysaccharide` antibody
* **Castenada’s** medium
* **Mx** = **4-6 weeks** of `doxycycline + gentamicin/streptomycin`
* Complications = `MEO`(W): `m`eningoencephalitis, `e`ndocarditis, `o`steomyelitis
131
# SUMMARY CARD:
* What are the features of **leptospirosis**?
* How does it spread?
* How is it diagnosed and managed?
BONUS: what are the symptoms of severe disease?
| Hint: interrogate; weil's disease
* **Leptospiroma interrogans** = gram -ve spirochaete
* `Rat urine`
* Fever + jaundice + `conjunctival haemorrhages`
* RFs = **sewage workers**, farmers
* **Mx** = `doxycycline` (or erythromycin)
BONUS: in severe disease (Weil’s disease) = AKI, aspetic meningitis
132
# SUMMARY CARD:
* What are the features of **lyme disease**?
* How does it spread?
* How is it diagnosed and managed?
| Hint: babiest baby (BB) loves avril lavigne --> BB = ?
* **Borrelia burgdorferi** = spirochaete
* `Ixodes ticks` --> RFs = hiking
* EARLY (localised) = bull’s eye rash (`erythema chronicum migrans`), flu-like Sx
* EARLY disseminated = fevers, myalgia, arthralgia, CNS/heart block Sx
* LATE (persistent) = carditis, malaise, meningitis, **3rd degree heart block** / CNS signs
* Ix: **ELISA** to BB then **immunoblot**
* **Mx** = `doxycycline` (amoxicillin in pregnancy OR ceftriaxone if disseminated)
133
# SUMMARY CARD:
* What are the features of **human plague**?
* How does it spread?
* How is it diagnosed and managed?
| Yessir pestis; causes dry gangrene slowly
* **Yersinia pestis** = gram -ve bacilli, lactose fermenter
* `R`ats = `r`esevoir, transmission by `fleas`
* NOTE: still seen in some American national parks e.g. Yosemite
* Swollen LN = `bubo`
* **Dry gangrene**
* **Ix = PCR**
* **Mx** = `c`auses `d`ry `g`angrene `s`lowly: `c`hloramphenicol + `d`oxycycline + `g`entamicin + `s`treptomycin
134
# SUMMARY CARD:
* What are the features of **athrax**?
* How does it spread?
* How is it diagnosed and managed?
* **Bacillus anthracis** = gram +ve rods with tripartite protein toxin
* `Cows`
* **Cutaneous** = painless `black eschars`
* **Pulmonary** = massive lymphadenopathy + `mediastinal haemorrhage` (CP + SOB + haemoptysis)
* GI = necrotic ulcers, perforation
* **Mx** = `doxycycline / ciprofloxacin`
135
# SUMMARY CARD:
* What are the features of **leishmaniasis**?
* How does it spread?
* How is it diagnosed and managed?
| 3 types: cutaenous, muco-cutaneous, + visceral
* **Leishmania major/tropica** (most common) = causes cutaenous
* Leishmania brazilensis = muco-cutaenous
* **Leishmania donovani** = causes visceral
* `Sandfly`
* **Cutaneous** (most common) = `scaly ulceration` at sandfly **bite** site
* **Muco-cutaenous** = starts off as dermal ulcer, then months-years later `ulcerative mucous membrane destruction` in nose / mouth
* **Visceral (Kala Azar)** = massive `splenomegaly`, usually **young malnourished child**, gradual onset fever, abdo discomfort, anorexia / weight loss
* Ix: NMN (Novy-Macneal-Nicolle); **splenic aspirate**
* **Mx** = `amphotericin B`
136
# SUMMARY CARD:
* What are the features of **sleeping sickness**?
* How does it spread?
* How is it diagnosed and managed?
| 2 types of brucei = GG + RR
* **Trypanosoma brucei** and Trypanosoma cruzi (chagas)
* NOTE: African sleeping sickness = Brucei gambiense
* T`s`et`s`e fly (`s`leeping `s`ickness)
* Brucei `g`ambiense (African) = `g`**radual** **infection** (GG)
* Brucei `r`hodesiense = `r`**apid infection** (RR)
* **Cruzi** = **acutely** Romana’s sign (`purple eyelid`); **chronically** `dysphagia` due to formation of megaoesophagus and megacolon
* **Mx** (early disease) = IV pentamidine; later disease = IV melarsoprol
137
# SUMMARY CARD:
* What are the features of **cat scratch disease**?
* How does it spread?
* How is it diagnosed and managed?
| cat --> chicken --> hen
* **Bartonella henselae** = gram -ve bacilli
* `Kitties`
* NOTE: cat scratch disease is a severe form of bacillary angiomatosis (a cutaneous infection caused by bartonella)
* RFs = immunocompetent
* `Macule` at site of **bite**
* **Mx** = erythromycin/`doxycycline`
138
# DISEASE:
23M - recently returned from medical elective in `Africa`
1/52 Hx of of **fever + myalgia + headaches**
What diagnostic investigation should be requested?
`Thick + thin blood films`
* **3x thick** = to check for parasites
* Thin = to quantify parasitaemia + demostrate the species; if >2% in children or >10% in adults –> severe
139
# DISEASE:
What is the management of severe malaria?
BONUS: if a patient develops haemoglobinuria - what is the complication called?
IV artesunate
BONUS: blackwater fever
140
# DISEASE:
BONUS q:
Most common cause of neutropenic sepsis in PUO?
| haven't covered this yet
Pseudomonas
141
# DISEASE:
20F - `Enteric fever` (AKA fever + GI Sx)
**Constipation**
Rose spots
**Relative bradycardia**
1. Diagnosis (+ causative organism)?
2. How does it spread?
3. Ix?
4. Mx?
1. **Typhoid fever** --> `salmonella typhi` (or paratyphi)
2. faeco-oral (contaminated food)
3. Ix = `blood culture` +/- stool culture (GOLD STANDARD)
Mx = IV `ceftriaxone`, then PO `azithromycin`
142
# DISEASE:
25F - severe **headache**, **retro-orbital** pain, **myalgia** + maculopapular rash
Fever
Travelled SE asia
`leukopenia + thrombocytopenia`
1. Diagnosis (+ pathogen)?
2. Vector?
3. What is seen on microscopy of the liver?
4. Mx?
| hint: inspection of liver
1. **Dengue fever** = `flavivirus`
2. Female `aedes mosquito`
3. **Councilman bodies** in hepatocytes
4. `Supportive` Mx
NOTE: bloods show `↓Hb, ↓WCC, ↓platelets`
143
# DISEASE:
50M - returned from **hiking** trip 1/52
**fever** + headache + **myalgia**
Maculopapular rash on `wrists + ankles initially`, now spread to trunk
`Black dots` on skin
1. Diagnosis (+ causative organism)?
2. Vector?
3. Mx?
| rocky = rickets
1. **Rocky Mountain Spotted Fever** = `rickettsial akari`
2. `Ticks` (liponyssoides sanguineus)
3. Sx = fever + headache + `rash that starts peripherally` (maculopapular to vasculitic) + `black eschars`
4. Mx = **doxycycline**
144
# DISEASE:
55M - homeless man w/ **agitation**, confusion, and `hydrophobia`
Bitten by **dog** 1 month ago
**febrile** + `hypersalivation`
1. Diagnosis (+ causative organism)?
2. Vector?
3. Mx?
1. **Rabies** = `rhabdovirus`
2. `Dogs` or bats
3. 100% mortality if CNS S&S
NOTE: normally give prophylactic vaccination course with IgG
145
# DISEASE:
33F - `farmer`
2/52 Hx of high **fever** + severe headache + myalgia, + **non-productive cough**
Helped deliver `livestock` 2/52 ago
febrile + mild hepatomegaly
1. Diagnosis (+ causative organism)?
2. Vector?
3. Ix?
4. Mx?
1. **Q fever** = `coxiella burnetti`
2. `Cattle` (farmers at risk, esp with fluid transmission)
3. CXR = **ground glass** appearance (due to atypical pneumonia presentation); `serology`
4. Mx = **doxycycline**
146
# DISEASE:
32M - recent trip to cheese factory + ate `unpasteurised cheese`
**sudden onset** fever
`orchitis`
back pain (`sacroiliitis`)
1. Diagnosis (+ causative organism)?
2. Vector?
3. Ix?
4. Mx?
1. **Brucellosis** = `brucella melitensis`
2. unpasteurised dairy / farm animals
3. Ix = **brucella serology**; `anti-O-polysaccharide` antibody (NOTE: castenada medium)
4. Mx = `doxycycline + gentamicin`
147
# DISEASE:
60M - 4/7 **flu-like** Sx
myalgia + abdo pain + jaundice
`retro-orbital headaches + conjunctival haemorrhages`
febrile
ECG + U&Es normal
1. Diagnosis (+ causative organism)?
2. Vector?
3. Mx?
BONUS: what is the severe form of this disease called?
| interrogate on elective
1. **Leptospirosis** = `leptospiroma interrogans`
2. `rat urine`
3. Mx = **doxycycline**
BONUS: **Weil's disease** (presets with AKI + aseptic meningitis)
148
# DISEASE:
38F - recent **hiking** trip
**fever** + **myalgia** + arthralgia
ECG shows `3rd degree heart block`
1. Diagnosis (+ causative organism)?
2. Vector?
3. Ix?
4. Mx?
1. **Lyme disease** = `borrelia burgdorfer`i
2. `Ixodes ticks`
3. Ix = **ELISA**
4. Mx = **doxycycline**
NOTE: bull's eye rash (erythema chronicum migrans) is seen in EARLY disease (pt is presenting with late S&S)
149
# DISEASE:
Cause of human plague + management?
| yessir
* `Yersinia pestis`
* RFs = **Yosemite** (reside in rats, spread by `fleas`)
* Mx = causes dry gangrene slowly --> `chloramphenicol + doxycycline + gentamicin + streptomycin`
NOTE: enlarged LNs called buboes (AKA bubonic plague)
150
# DISEASE:
45M - `painless black eschars`
**farmer**
now presenting with `CP + SOB + haemoptysis`
1. Diagnosis (+ causative organism)?
2. Vector?
3. Ix?
4. Mx?
1. **Anthrax** = `bacillus athracis`
2. `Cows`
3. CXR = `mediastinal haemorrhage`; colonoscopy = GI ulcers + perforation
4. Mx = `doxycycline / ciprofloxacin`
151
# DISEASE:
35F - non-healing scaly ulceration at bite site
1. Diagnosis (+ causative organism)?
2. Vector?
3. Ix?
4. Mx?
1. **Leishmaniasis** (cutaenous = `leishmania major/tropica`)
2. `Sandfly`
3. Ix: NMN (Novy-Macneal-Nicolle); `splenic aspirate`
4. Mx = amphotericin B
152
# DISEASE:
How is sleeping sickness spread?
What is the causative organism for:
1. gradual fever onset?
2. rapid fever onset?
3. purple eyelid + chronic dysphagia?
* `Tsetse fly`
1. Trypanosoma `brucei` **gambiense** (African) = gradual infection (GG)
2. Trypanosoma `brucei` **rhodesiense** = rapid infection (RR)
3. Trypanosoma `cruzi` = acutely Romana’s sign (purple eyelid); chronically dysphagia due to formation of megaoesophagus and megacolon
153
# DISEASE:
8F - playing with new kitten
macule at bite site
1. Diagnosis (+ causative organism)?
2. Vector?
4. Mx?
* **Cat scratch disease** = `bartonella henselae`
* `Cats`
* Mx = **doxycycline**
154
# SUMMARY CARD:
What are the causative organisms of the following worms:
1. Tapeworm from pork
2. Tapeworm from beef
3. Tapeworm from dogs
4. Schistomiasis
5. Ascariasis
6. Hookworm infection
7. Threadworm
8. Strongyloidiasis
9. Elephantiasis
10. Onchocerciasis (or river blindness)
1. Tapeworm from **pork** = `taeniae solium`
2. Tapeworm from **beef** = `taeniae saginata`
3. Tapeworm from **dogs** = `echinococcus granulosus`
4. **Schistomiasis** = `schistosoma haematobium` (flukes)
5. **Ascariasis** = `ascaris lumbricoides` (roundworm)
6. **Hookworm** infection = `ancyclostoma duodenale` (roundworm)
7. **Threadworm** = `enterobius vermicularis` (sounds italian)
8. **Strongyloidiasis** = `strongyloides stercoralis` (roundworm)
9. **Elephantiasis** = `wuchereria bancrofti` (roundworm)
10. **Onchocerciasis** (or river blindness) = `onchocerca volvulus` (roundworm)
155
# SUMMARY CARD:
What are the S&S (+/- Ix +/- Mx) of each of the following tapeworms:
1. From pork
2. From beef
3. From dogs
| solium, saginata, lots of c's for liver cysts
1. Tapeworm from **pork** (`taeniae solium`)
AND 2. from **beef** (`taeniae saginata`):
* Mass lesions in the brain w/ `swiss cheese appearance`
* Mx: -bendazoles
3. Tapeworm from **dogs** (`echinococcus granulosus`):
* `Liver cysts`
* If cyst ruptures, then **anaphylactic like reaction**
* Mx = -bendazoles
156
# SUMMARY CARD:
What are the S&S (+/- Ix +/- Mx) of each of:
1. Flukes
2. Threadworms
1. **Flukes** = `schistosoma haematobium` (AKA **schistomiasis**)
* `Itchy rash` + painless haematuria
* RFs = **swimming**
* Katayama fever (fever, rash, myalgia, **hepatosplenomegaly**)
* Bladder calcification
* `↑ risk of bladder SCC`
* Mx: `Praziquantel` (increases permeability towards Ca2+)
2. **Threadworms** = `enterobius vermicularis`
* `Perianal itching` especially at night
* **Vulval** symptoms in females
* Ix = **sticky plastic tape** to perianal area
* Mx = `mebendazole` for patient + **family members**
157
# SUMMARY CARD:
What are the S&S (+/- Ix +/- Mx) of each of the following roundworms:
1. Ascariasis
2. Hookworm
3. Strongyloidiasis
4. Elephantiasis
5. Onchocerciasis
1. **Ascariasis** = `ascaris lumbricoides`
* Soil transmitted helminth (giant roundworm)
* Intestinal obstruction
* Loffler’s syndrome = eosinophilic pneumonia
2. **Hookworm** infection = `ancyclostoma duodenale`
* Larvae `penetrate skin of feet` (transdermal)
* Causing **GI infections** (which lead to `anaemia` as worms attach to the intestinal wall + feed on blood, causing chronic intestinal blood loss)
* Mx = albendazole, me**bendazole**
3. **Strongyloidiasis** = `strongyloides stercoralis` (roundworm)
* Diarrhoea + abdominal pain
* Papulovesicular lesions where the **skin** has been **penetrated** by infective larvae, larva currens
* Mx = `ivermectin` (activated glutamate-gated chloride channels)
4. **Elephantiasis** = `wuchereria bancrofti`
* Transmission by `female mosquito`
* Causes **blockage of lymphatics** → fluid accumulation + swelling (elephantiasis)
* Mx = dietylcarbamazine (inhibits arachidonic acid metabolism)
5. **Onchocerciasis** (or river blindness) = `onchocerca volvulus`
* **River blindness **(visual impairment due to ocular lesions + inflammation) + hyperpigmented skin
* **Allergic reaction** to microfilaria (AKA **larvae**)
* Mx = `IVER`mectin for r`IVER`blindness
158
# DISEASE:
What is the characteristic appearance of brain lesions caused by Taeniae solium and Taeniae saginata infection?
swiss cheese
159
# DISEASE:
Burst liver cyst causes anaphylactic-like reaction
1. Diagnosis?
2. Mx?
* **Tapeworm** infection = `echinococcus granulosus`
* Mx = mebendazole
160
# DISEASE:
Itchy rash after swimming
fever + hepatosplenomegaly
1. diagnosis?
2. Mx?
BONUS: ↑ risk of which cancer?
1. **Schistomiasis** = `schistosoma haematobium` (flukes)
2. Mx = Praziquantel
BONUS: ↑ risk of bladder cancer
161
# DISEASE:
Which syndrome, characterized by eosinophilia pneumonia, is associated with ascaris lumbricoides infection?
Loeffler's syndrome
162
# DISEASE:
How do larvae of ancyclostoma duodenale typically enter the human body
| (AKA hookworm)
Hookworm --> penetration through the skin
163
# DISEASE:
What is the primary symptom of Enterobius vermicularis infection in children?
perianal itching
Mx = mebendazole for WHOLE household
164
# DISEASE:
What is the primary mode of transmission of strongyloides stercoralis infection to humans?
Penetration through skin
165
# DISEASE:
Elephantiasis is caused by which organism?
Wuchereria bancrofti
Mx = diethylcarbamazine
166
# DISEASE:
Which medication is the primary treatment for Onchocerca volvulus infection?
| AKA river blindness
Ivermectin (cause r`iver` blindness)
167
# SUMMARY CARD:
What is the **causative organism + Sx** (+/- Ix +/- Mx) of the following superficial fungal infections?
1. Athlete's foot
2. Tinea capitis
3. Pityriasis versicolor
**1. Athlete's foot** = `tinea dermatophyte` (ringworm)
* Specifically `trichophyton rubrum` causes athlete’s foot
* Scaly / peeling / cracked skin between toes
* **Mx** = **topical** antifungal e.g. clotrimazole (oral considered if complex e.g. multiple sites of infection or toe nail infection)
* NOTE: Potassium hydroxide mixed with nail/skin clippings is a decent diagnostic test for the presence of tinea or trycophyton
**2. Tinea capitis** = `tinea dermaphyte` on scalp (scalp ringworm)
* Scaly + itchy patches + `well defined patches of hair loss`
* Painful, swollen lymph nodes
* Mx = **systemic** antifungals (e.g. terbinafine) + anti-fungal shampoos to reduce transmission
* NOTE: always order LFTs before starting terbinafine as it is metabolised by the liver
**3. Pityriasis versicolor** = malassezia furfur
* **Flaky discolouration** (hypopigmentation); asymptomatic
* Microscopy = `spaghetti + meatballs` appearance
* Wood's Lamp = patches that fluoresce a faint orange colour
* Mx = **topical** antifungal e.g. ketoconazole
168
# SUMMARY CARD:
What is the **causative organism + Sx** (+/- Ix +/- Mx) of the following deep seated fungal infections?
1. Candidiasis
2. Cryptococcis
3. Histoplasmosis
4. Aspergillosis
5. Mucormycosis
6. Onychomycosis
7. Sporotrichosis
**1. Candidiasis** = `candida albicans` (yeast)
* Deep-seated infections (e.g. `oesophagitis` = **odynophagia**) in the immunocompromised
* 'Cottage cheese' like
* Ix = **Germ tube test** (for albicans)
* Mx = `fluconazole` (or amphotericin B for invasive disease)
* NOTE: if non-albicans disease, use caspofungin (type of echinocandin)
**2. Cryptococcis** = `cryptococcus neoformans` (yeast)
* Found in `pigeon` droppings
* Main RF = immunosuppression
* Sx = insidious onset **meningitis** in HIV
* Ix = `India ink` stain → yeast cells surrounded by halos
* Mx = **amphotericin B**
**3. Histoplasmosis** = `histoplasma capsulatum`
* Found in bird / bat **droppings**
* Causes chronic `progressive lung disease` (Sx = cough, chest pain, + fever)
* Endemic to the Mississippi River region
**4. Aspergillosis** = `aspergillus`
* Aspergillus `flavus` = stored grains/peanuts + produces **aflatoxin** that can lead to hepatocellular carcinoma
* Ix = **galactomannan** ELISA (part of aspergillus cell wall)
* Staining = methenamine silver stain
* Mx = `amphotericin B` (longer course than cryptococcus)
* Aspergillus **fumigatus** = causes allergic bronchopulmonary aspergillosis, aspergilloma, + invasive aspergillosis in those with `cystic fibrosis`
* NOTE: its burkholderia cepecia that is CI for lung transplant in CF pts
**5. Mucormycosis** = `rhizopus + mucor` (AKA 'black fungus')
* **Black pus** from nose/mouth
* Very severe in immunocompromised/poorly controlled diabetes
* Sx = cellulitis, `necrotic destructive lesions` around the face e.g. jaw
* Mx = `surgical debridement` + **amphotericin B**
**6. Onychomycosis**
* Thickened nails
* Mx = `Nail lacquers / turbinafine`
**7. Sporotrichosis** = `sporothrix schnekenii`
* Caused by **rose pricks**
* RF = rose gardeners
* `Painless nodular lesion`, rash + ascending lymphadenopathy
* May lead to bone/joint/muscle involvement
169
# DISEASE:
What organism causes athlete's foot?
BONUS: if the infection is in the nails, what test can you do for a quicker result than culture?
`Trichophyton rubrum`
BONUS: KOH → mixed with nail/skin clippings can test for presence of tinea or trycophyton
170
# DISEASE:
18M - `well-defined areas` of **hair loss** with broken hair shafts
1. Diagnosis?
2. Mx?
BONUS: what to order on blood test before starting the Mx?
1. **Tinea capitis**
2. Mx = systemic antifungals (e.g. `terbinafine`) + anti-fungal shampoos to reduce transmission
BONUS: order **LFTs** before starting terbinafine as it is metabolised in the liver
171
# DISEASE:
20M - **rash** on back after holiday in **humid** country (+ didn't shower)
`Scaly hypopigmented areas`
**Asymptomatic**
Under Wood's Lamp = faint orange fluorescence
1. Diagnosis?
2. Mx?
1. **Pityriasis versicolor** (AKA tinea versicolor) = `malassezia furfur`
2. Topical antifungal e.g. ketoconazole
172
# DISEASE:
35M - HIV-positive patient has odynophagia
White, 'cottage cheese' patches in the mouth
1. Diagnosis?
2. Ix?
2. Mx?
1. **Candidiasis** = `candida albicans`
2. Ix = **Germ tube test** (for albicans)
3. Mx = `fluconazole`
173
# DISEASE:
46M - **neck stiffness, fever, and photophobia**
PMHx = **HIV**, poor compliance to medications
LP + `India ink` stain = CSF positive for yeast cells w/ a gelatinous capsule and a `positive halo sign`
1. Diagnosis?
2. Mx?
1. Cryptococcus neoformans
2. Amphotericin B
174
# DISEASE:
50M - farmer presents with **chronic cough + chest pain + fever**
He resides near the `Mississippi River`
1. Diagnosis?
2. Vector?
1. **Histoplasmosis** = `Histoplasma capsulatum`
2. Found in bird/bat droppings → causes chronic progressive lung disease; endemic to Mississippi river
175
# DISEASE:
What fungal antigen may be detected in blood samples in a patient with invasive aspergillosis?
Galactomannan
176
# DISEASE:
60M - `severe haemoptysis`
PMHx = COPD + poorly controlled HIV
CT scan = multiple large bullae + large left upper lobe rounded mass with surrounding air crescent Serum **galactomannan** = positive
1. Diagnosis?
2. Increase in risk of which type of cancer?
1. **Aspergilloma** = `aspergillus`
2. If aspergillus flavus → produces **aflatoxin** that can lead to hepatocellular carcinoma (`HCC`)
177
# DISEASE:
65F - **black pus** from the nose + severe facial `cellulitis` on the `jaw`
PMHx = diabetes
O/E = `necrotic lesions` around the face
1. Diagnosis?
2. Mx?
1. **Mucormycosis** = `rhizopus` and `mucor`
2. **Surgical debridement** (+ amphotericin B)
178
# DISEASE:
45F - `thickened nails` on her hands and feet
Diagnosis?
Onychomycosis
179
# DISEASE:
40F - gardener
**Painless nodular** lesions on arm following `rose prick` injury
Diagnosis?
**Sporotrichosis** = `sporothrix schnekenii`
NOTE: may also present with ascending lymphadenopathy
180
# SUMMARY CARD:
What is the mechanism of action (+/- adverse effects) of the following anti-fungal medications:
1. -azoles
2. Amphotericin B (polyene)
3. Terbinafine
4. Griseofulvin
5. Flucytosine
6. Caspofungin
7. Nystatin
**1. -azoles**
* Targets `cell membrane synthesis` → inhibits 14α-demethylase which produces **ergosterol**
* AEs = P450 inhibition, liver toxicity
* Indications = yeast
**2. Amphotericin B (polyene)**
* Targets `cell membrane integrity` → binds with **ergosterol** forming a transmembrane channel that leads to monovalent ion (K+, Na+, H+ and Cl) leakage
* AEs = nephrotoxicity, flu-like symptoms, hypokalaemia, hypomagnaseamia
* **Indications** = `systemic fungal infections e.g. cryptococcus, aspergilloma`
**3. Terbinafine**
* Targets `cell membranes` → inhibits **squalene** **epoxidase**
* Indications = oral form used to treat `nail infections`
**4. Griseofulvin**
* Interacts w/ microtubules to disrupt mitotic spindle
* AEs = induces P450 system, teratogenic
**5. Flucytosine**
* Inhibits `DNA synthesis` → converted by cytosine deaminase to 5-fluorouracil, which inhibits thymidylate synthase and disrupts fungal protein synthesis
* AE = vomiting
**6. Caspofungin (echinocandin)**
* Targets `cell wall` → inhibits synthesis of beta-glucan (fungal cell wall component)
* AEs = flushing
* Indications = yeast infections (less toxic SEs)
**7. Nystatin**
* Targets `cell membrane integrity` → binds with **ergosterol** forming a transmembrane channel that leads to monovalent ion (K+, Na+, H+ and Cl) leakage
* Due to toxicity, can only be used `topically` (e.g. for oral thrush)
181
# SUMMARY CARD:
What are the **causative organisms** of the following congenital infections:
1. Toxoplasmosis
2. Neonatorum opthalmia
3. Parvovirus
4. Varicella Zoster Virus
5. Rubella
6. Cytomegalovirus
7. Herpes Simplex Virus
8. HIV
9. Syphilis
10. Congenital zika
| TORCH (Toxoplasmosis, Other (HIV, HBV), Rubella, CMV, HSV)
1. **Toxoplasmosis** → `toxoplasma gondii`
2. **Neonatorum opthalmia** → `chlamydia trachomatis / neisseria gonorrhoeae`
3. **Parvovirus** → `parvovirus B19`
4. **Varicella Zoster Virus** → `VZV` (HHV3 is the most common VZV)
5. **Rubella** → `Rubella`
6. **Cytomegalovirus** → `CMV` (HHV5 is the most common CMV)
7. **Herpes Simplex Virus** → `HSV`
8. **HIV** → `HIV`
9. **Syphilis** → `treponema pallidum`
10. Congenital Zika → `zika virus`
182
# SUMMARY CARD:
* What are the features of **congenital toxoplasmosis**?
* How is it diagnosed +/- managed?
* *`Toxoplasma gondii`*
* 60% **asymptomatic** at birth (but later develop `low IQ + deafness`)
* 40% **symptomatic** → cerebral calcification triad = `seizures, hydrocephalus, chorioretinitis` (+ cataracts)
* NOTE: Seize (seizures) High (hydrocephalus) Colours (chorioretinitis)
* Mx = pyrimethamine
183
# SUMMARY CARD:
* What are the features of **neonatorum opthalmia**?
* How is it diagnosed +/- managed?
* *`Chlamydia trachomatis / Neisseria gonorrhoeae`*
* `Newborn conjunctivitis` → **same-day ophthalmology assessment**
184
# SUMMARY CARD:
* What are the features of **congenital parvovirus**?
* How is it diagnosed +/- managed?
* *`Parvovirus B19`*
* Can **cross the placenta** in pregnant women
* Causes severe **anaemia** and consequent **heart failure** in the `foetus`, leading to `hydrops fetalis` (ascites, pleural +/- pericardial effusions)
* Ix = maternal serology to check for IgM against parvovirus B19; PCR to detect parvovirus B19 DNA
* Mx = regular monitoring for complications
185
# SUMMARY CARD:
* What are the features of **congenital VZV**?
* How is it diagnosed +/- managed?
* *`Varicella Zoster Virus`* (most common = **human herpes virus 3**)
* Congenital varicella syndrome only occurs if mother infected within `20 weeks gestation`
* `I`nfections `C`an `C`ause `M`any `L`ifelong `C`omplications
* `I`**UGR** (Intrauterine Growth Restriction)
* `C`**ataracts**
* `C`horioretinitis
* `M`icrocephaly
* `L`**imb hypoplasia**
* `C`utaneous scarring
* NOTE: maternal infection during time of delivery can lead to severe, disseminated infection in the newborn
* Mx = check maternal IgG antibody to varicella zoster → if negative, `oral aciclovir`
186
# SUMMARY CARD:
* What are the features of **congenital rubella**?
* How is it diagnosed +/- managed?
* *`Rubella virus`*
* **RARE** due to MMR vaccine
* Triad = `c`**ataracts**, `p`**atent ductus arteriosus**, `s`**ensorineural deafness**
* NOTE: mnemonic for triad = `C`hild `P`rotective `S`ervices
* Most common in `first trimester`, **low risk after 20 weeks**
* Ix = maternal IgM + IgG serology; PCR for rubella virus RNA
* Mx = supportive
187
# SUMMARY CARD:
* What are the features of **congenital CMV**?
* How is it diagnosed +/- managed?
| hoot hoot
* *`Cytomegalovirus`* (human herpes virus 5 = most common)
* `G`reat `M`others `P`rotect `E`very `H`alf `S`ibling
* `G`**rowth retardation**
* `M`**icrocephaly**
* Pinpoint `p`**etechial** 'blueberry muffin' skin lesions
* `E`**ncephalitis** (seizures)
* `H`**epatosplenomegaly**
* `S`ensorineural **deafness**
* NOTE: complications in the baby are uncommon if infection occurs beyond 20 weeks’ gestation
* Histology = “`Owl’s eye`” appearance → intranuclear inclusion bodies
* **Mx** = `ganciclovir`
188
# SUMMARY CARD:
* What are the features of **congenital HSV**?
* How is it diagnosed +/- managed?
* *`Herpes simplex virus`*
* Most likely transmitted to neonate in the **third trimester**
* 3 forms of neonatal herpes simplex infection:
* **Localised** to `SEM` (skin, eye, and mouth) disease causing a `blistering rash`
* **Localised** to `CNS` causing `meningoencephalitis`
* `Disseminated` infection casuing **multiple organ involvement**
* Mx = IV aciclovir
189
# SUMMARY CARD:
* What are the features of **congenital HIV**?
* How is it diagnosed +/- managed?
* *`Human immunodeficiency virus`*
* ↑ risk of intrauterine transmission from HIV-positive mother to child
* Newborn with **HIV** = failure to thrive, developmental delay, `recurrent / opportunistic infections`, **progressive encephalopathy**
* **Mx** = `ART (zidovudine)` for **mother** to get viral load < 50 HIV RNA copies/mL at 36 weeks' gestation; `neonatal ART prophylaxis` should be commenced within 4 hours after birth + given for 4 weeks
* NOTE: maternal viral load is the most predictive factor for perinatal HIV transmission
190
# SUMMARY CARD:
* What are the features of **congenital syphilis**?
* How is it diagnosed +/- managed?
* *`Treponema pallidum`*
* Mnemonic: `S`yphilis `R`eally `H`as `U`gly `H`idden `M`arkers
* `S`addle-rash deformity
* `R`ash on hands and soles
* `H`epatosplenomegaly
* `U`**nilateral enlargement of clavicle**
* `H`**utchinson’s teeth**
* `M`**ulberry molars**
* Ix = syphilis screening assay
191
# SUMMARY CARD:
* What are the features of **congenital zika virus**?
* How is it diagnosed +/- managed?
* *`Zika virus`* (enveloped flavivirus)
* **Severe microcephaly + skull deformity**
* Secreased brain tissue, subcortical calcification
* Retinopathy + deafness
* Talipes (feet turned in like club foot)
* Hypertonia
192
# SUMMARY CARD:
What are the causes of `early` vs. `late` onset **neontal sepsis**?
Neonatal = < 6 weeks old
**Early onset sepsis = `< 48hrs` after birth**
* Pathogens = `Group B streptococcus`, E. coli, Listeria monocytogenes
* Maternal Sx = (P)PROM, fever, foetal distress
* **Neonatal Sx** = respiratory distress, acidosis, fever, clinically unwell
* Ix = `SEPTIC SCREEN` (FBC, CRP, blood culture, ABG, urinalysis, LP, CXR)
* Mx = `Benzyl penicillin + gentamicin + amoxicillin/ampicillin` (for listeria cover)
**Late onset sepsis = `> 48hrs` after birth**
* Pathogens = **Coagulase -ve staph** (e.g. epidermidis, haemolyticus, saphrophyticus), Group B streptococcus, E. coli, Listeria monocytogenes
* **Neonatal Sx** = bradycardia, apnoea, poor feeding, irritability
* Ix = `SEPTIC SCREEN` (FBC, CRP, blood culture, ABG, urinalysis, LP, CXR)
* **Mx** = `benzylpenicillin + gentamicin` (2nd line: Tazocin + vancomycin)
* Mx for late onset from community = amoxicillin + cefotaxime
193
# SUMMARY CARD:
Most common causative organisms of bacterial meningitis in:
1. > 3 months of age
2. < 2 years old
3. < 3 months old + unvaccinated
4. 1-3 months old
1. > 3 months of age = **neisseria meningitidies** (non-blanching petechial rash AKA meningococcal septicicaemia)
2. < 2 years old = **streptococcus pneumoniae**
3. < 3 months old + unvaccinated = **haemophilus influenzae**
4. 1-3 months old = **GBS** / E.coli / listeria
194
# DISEASE:
What is the `triad` of symptoms caused by **toxoplasmosis**?
| seize high colours
TRIAD = `s`**eizures**, `h`**ydrocephalus**, `c`**horioretinitis**
Mnemonic = Seize (seizures) High (hydrocephalus) Colours (chorioretinitis)
(still waiting for a better one sigh)
195
# DISEASE:
**Newborn** - `bilateral purulent eye discharge`
Born to a mother with no prenatal care or STI screening
**Vaginal delivery**
* Likely causative pathogen?
Neisseria gonorrhoea or chlamydia trachomatis
196
# DISEASE:
What condition is a foetus at risk of if its mother is infected by **Parvovirus B19**?
`Hydrops fetalis` (effusions + ascites)
197
# DISEASE:
What are the features of **congenital VZV**?
| `I`nfections `C`an `C`ause `M`any `L`ifelong `C`omplications
`I`nfections `C`an `C`ause `M`any `L`ifelong `C`omplications
* `I`**UGR** (Intrauterine Growth Restriction)
* `C`**ataracts**
* `C`horioretinitis
* `M`icrocephaly
* `L`**imb hypoplasia**
* `C`**utaneous scarring**
198
# DISEASE:
What is the triad of Sx in congenital rubella?
| `c`hild `p`rotective `s`ervices
`C`hild `P`rotective `S`ervices
* `C`**ataracts**
* `P`**DA** (patent ductus arteriosus)
* `S`ensorineural **deafness**
199
# DISEASE:
Newborn - bilateral `cataracts` + retinopathy
Heart murmur (`continuous, “machinery” murmur` below the clavicle)
Bilateral `hearing loss` on otoacoustic emission test
Abdominal mass
Mother has no known past medical history
* Likely viral exposure during pregnancy?
Rubella
200
# DISEASE:
2 wk old neonate - `microcephaly` + `petechial rash` + **hepatosplenomegaly**
Peripheral blood leukocytes reveals intranuclear `inclusion bodies`
* What congenital virus is the most likely cause of these findings?
`Cytomegalovirus (CMV)`
NOTE: `G`reat `M`others `P`rotect `E`very `H`alf Sibling
* Growth retardation
* **Microcephaly**
* Pinpoint **petechial** ‘blueberry muffin’ skin lesions
* Encephalitis (seizures)
* **Hepatosplenomegaly**
* Sensorineural deafness
* Histology = “`Owl’s eye`” appearance → intranuclear inclusion bodies
201
# DISEASE:
Rash on baby’s face
The examination notes made by the neonatologist: ‘10-hour old baby. **Widespread vesicles and pustules** on `face, lips` involved. Eyes not involved. Salmon patch on left eyelid. Milia on nose. **No other abnormalities**. Obs reviewed and normal.'
* What is the most likely causative organism?
Neonatal herpes simplex infection - characterised by vesicles and pustules involving the face + mouth
**Neonatal herpes simplex** infection can manifest in **3 forms**: localised to the skin, eyes and mouth (`SEM`), localised to the central nervous system (i.e. `encephalitis`) and `disseminated` infection.
202
# DISEASE:
What is the tooth deformity in congenital syphilis?
Hutchinson’s teeth
Mulberry molars
203
# DISEASE:
Newborn - `rash` on the **hands + soles**, `saddle-rash` deformity, + `hepatosplenomegaly`
O/E = `unilateral enlargement of the clavicle`
* Which congenital infection?
Syphilis
204
# DISEASE:
28F - antenatal scan at 32 weeks
**Recent travel to South America**
USS shows: `foetal microcephaly + skull deformity w/ intracranial calcifications + club feet`
* What is the most likely congenital infection?
Zika virus
205
# SUMMARY CARD:
What are some examples of viruses in:
1. **Herpesviridae** (cause latent infections)
2. **Polyomaviridae**
3. **Respiratory** **viruses**
4. **Hepatitis viruses**
BONUS: how do viral infections affect the immunocompromised differently?
1. **Herpesviridae** (may cause latent infections): `CMV, EBV, HSV, HHV6, HHV8, VZV`
2. **Polyomaviridae**: `JC` (John Cunningham) virus (leads to PML if given mycophenolate mofetil) + `BK` (Human polyomavirus 1) virus
3. **Respiratory viruses**: `influenza` A + B, `parainfluenzae`, Respiratory
Syncytial Virus (`RSV`), `adenovirus, coronavirus`
4. **Hepatitis** **viruses**: `A` (normally vaccinate prior to immunosuppression), `B`, `C`, `D`, `E`
BONUS: `4 D's` = `D`issemination, `D`ifferent organs, `D`isastrous severity, `D`ysplasia
206
# SUMMARY CARD:
Virology basics:
* All **DNA** viruses are **double** stranded `EXCEPT`...
* All **RNA** viruses are **single** stranded `EXCEPT`...
* `Parvovirus` = DNA virus that is single stranded
* `Reoviridae` (e.g. **rotavius**) = RNA virus that is double stranded
NOTE: RNA viruses can be +ve sense or -ve sense → +ve sense means the RNA can be directly translated, whereas -ve sense means the RNA cannot be directly translated
207
# SUMMARY CARD:
What are some features of the following **herpesviridae**:
1. CMV
2. EBV
3. HSV
4. HHV6
5. HHV8
5. VZV
**1. CMV**
* Enveloped, **dsDNA** genome
* Lies latent in monocytes + dendritic cells
* CMV cells = "`owls eye`" (inclusion bodies)
* Sx in immunocompromised (affects esp. **transplant patients**) = encephalitis, retinitis, pneumonitis, colitis, marrow suppression, **oesophagitis (`LINEAR` ulcers)**
* **Mx** = IV `Ganciclovir` / PO valganciclovir (1st line); IV Foscarnet (2nd line)
**2. EBV**
* Enveloped, **dsDNA** genome
* Lies latent in B cells
* `NOTE: EBV not dangerous in pregnancy!`
* Glandular fever = **TRIAD** of `fever, pharyngitis, lymphadenopathy`
* Ix = blood film (**atypical lymphocytes** peripherally - stretched out cytoplasm), EBV serology
* **Monospot agglutination** (AKA heterophile antibody test AKA Paul-Bennell test) = diagnostic
* Mx = supportive
* Mx w/ **penicillins** in glandular fever may provoke a `morbilliform eruption` (widespread maculopapular rash)
* As EBV can lie dormant in B-cells, it `predisposes to Burkitt’s lymphoma`
* **Post-transplant** Lymphoproliferative Disease (PTLD) in **immunocompromised** Patients → Mx w/ `Rituximab` (anti-CD20 monoclonal Ab)
* Mnemonic: `BBB` → E`B`V, resides in `B` cells, predisposes to `B`urkitt's lymphoma
**3. HSV**
* Enveloped, **dsDNA** genome
* Lies latent in sensory neurons
* `HSV-1` → herpes **labialis** (**cold sores**) = severe painful ulceration, erythematous base +/- fever + submandibular lymphadenopathy
* Differential – Herpangina (Coxsackie A)
* `HSV-2` → **genital** ulceration = fever, dysuria, malaise, Inguinal lymphadenopathy, pain, + vesicular rash
* HSV-2 may cause **sacral radiculomyelitis** → urinary retention (self limiting)
* NOTE: HSV-1 more likely to cause encephalitis, whereas HSV2 is more likely to cause meningitis
* Sx in immunocompromised: cutaneous **dissemination**, **oesophagitis** causing odynophagia (`CIRCULAR` **ulcers**), hepatitis, viraemia, **herpetic whitlow** (HSV skin infection)
* Mx = `aciclovir` (or valaciclovir, 'val' meaning ucreased bioavailability to take orally)
**4. HHV6**
* AKA **roseola** virus
* Latent in monocytes / lymphocytes
* Roseola infantum ( = exanthum subitum, Sixth disease) → **FEVER then** sudden appearance of a maculopapular **rash** (starts on `trunk` + spreads to face / extremities)
* Most common cause of `febrile convulsions`
* Transmits via droplet infection
* Supportive Mx
**5. HHV8**
* AKA Kaposi's sarcoma
* Enveloped, **dsDNA** genome
* Genital transmission
* **Kaposi's sarcoma** seen in immunocompromised, esp. due to `HIV`
* Mx = chemoradiotherapy + surgical excision + HAART for underlying HIV
* If HHV8 associated with **EBV co-infection** → primary effusion `lymphoma`
**6. VZV**
* Enveloped, **dsDNA** genome
* Lies latent in `sensory` neurons; hence dermatomal distribution when it is reactivated
* Chickenpox Sx = fever + headache followed by **itchy rash**
* Eye involvement = `opthalmic herpes zoster`
* **Facial palsy** (unilateral facial drooping) + vesicles in **ear** = `Ramsay hunt syndrome`
* Shingles (reactivation) RFs = older, stress, ↓ immunity
* Shingles Sx = painful rash in specific **dermatome**
* In immunocompromised, more likely to cause `retinal necrosis + multidermatomal shingles`
* Mx w/ `aciclovir` if adult / immunocompromised neonate / eye involvement
208
# SUMMARY CARD:
What are some features of the following **polyomaviridae**:
1. JC (John Cunningham) virus
2. BK (Human polyomavirus 1) virus
**1. JC (John Cunningham) virus**
* Unenveloped, **dsDNA** genome
* In immunocompromised (especially AIDS): Progressive multifocal leukoencephalopathy (`PML`)
+ rapidly `demyelinating disease` (+ neurological deficits)
* Mx = HAART for HIV
**2. BK (Human polyomavirus 1) virus**
* Unenveloped, **dsDNA** genome
* In immunocompromised (esp. **transplant**): BK haemorrhagic cystitis + `BK nephropathy` (as it lies dormant in kidneys)
* Mx = **Cidofovir**
209
# SUMMARY CARD:
What are some features of the following **respiratory viruses**:
1. Influenzae virus
2. Adenovirus
3. Coronavirus
**1. Influenzae virus**
* Enveloped, negative sense segmented genome (8 segments)
* Antigenic `DRIFT` = point mutations
* Antigenic `SHIFT` = segments rearrange (can cause pandemics)
* Sx = URTI + systemic features include muscle aches
* **Haemagglutinin** activity = binds to sialic receptors + allows for virus **ENTRY**
* **Neuraminidase** activity = cleaves sialic acid + allows for **EXIT** of virions from host cell
* Mx = oral `oseltamivir` (neuraminidase inhibitor) - AKA Tamiflu
* Other Mx = polymerase inhibitor (e.g. Baloxavir)
**2. Adenovirus**
* Unenveloped, dsDNA genome
* In immunocompromised (especially transplant): encephalitis, **pneumonitis**, colitis, haemorrhagic cystitis
* **Supportive** Mx, unless multi-organ involvement, then Cidofovir +/- IVIG
**3. Coronavirus**
* **Positive sense ssRNA** genomes
* URTI +/- systemic symptoms e.g. myalgia
* Severe infections can cause ARDS, respiratory failure, shock, multiple organ dysfunction
* Mx = supportive OR **dexamethasone + remdesivir** if severe
210
# SUMMARY CARD:
What are some features of the following **hepatides**:
1. Hepatitis A
2. Hepatitis B
3. Hepatitis C
4. Hepatitis D
5. Hepatitis E
**1. Hepatitis A**
* Unenveloped picornavirus, **positive sense ssRNA** genome
* **Acute** infection
* **Faeco-oral** transmission
* Acute hepatitis = 2-6 weeks incubation, severe in elderly
* Ix = `anti-HAV IgM` in acute infection (IgM persists up to 14wks)
* Mx = supportive; Hep A vaccine available
**2. Hepatitis B**
* Enveloped hepadnavirus (reversivirus); hybrid
genome, mostly DNA
* Transmission via **bodily fluids** i.e. sexual, vertical, blood products
* Acute (90% resolve in >5 y/o) or chronic
* HBV at risk of `reactivation` in **immunocompromised** e.g. Rituximab
* **HBV serology**
* `HbsAg` (surface antigen) = present in acute or chronic infection, but negative in previous or vaccinated
* Anti-HBs (hep B surface antibody) = negative in acute or chronic infection, but positive in previous or vaccinated
* *NOTE: vaccine does NOT have core antigen!*
* So to differentiate between vaccine vs previous infection → vaccine does not have `anti-HBc IgG` but if previously infected, you would
* To differentiate between acute vs chronic infection → `anti-HBc IgM` in acute and anti-HBc IgG in chronic
* **HBe = infectivity**
* Mx = interferon alpha, lamivudine (nucleoside analogue), entecavir (nucleoside analogue), telbivudine (nucleoside analogue), tenofovir (nucleoTide analogue)
**3. Hepatitis C**
* Enveloped flavivirus, positive sense ssRNA genome
* Mainly a chronic disease (acute less common) - hep `C` for `C`**hronic**
* **Blood** borne = infected needles, blood transfusions etc.
* `C`omplications = `c`irrhosis, cryoglobulinaemia, glomerulonephritis
* Measure **HCV RNA** to confirm infection and assess treatment response (anti-HCV Ab develops after acute infection)
* Mx = Peg INF alpha
* Curative Mx = NS3/4 protease inhibitors (-previrs, block translation e.g. telaprevir, boceprevir) + NS5A inhibitors (-asvirs, block release e.g. ledipasvir, daclatasvir) + direct polymerase inhibitors (-buvirs,
block replication e.g. sofosbuvir, dasabuvir)
**4. Hepatitis D**
* Deltavirus, enveloped virus, negative sense,
single-stranded circular RNA
* **Can only infect those with Hep B**
* Transmission = sexual, perinatal
* May be a **coinfection** (simultaneously) with Hep B OR **superinfection** (on top of chronic) Hep B (`more severe` – often leads to cirrhosis within 2-3yrs)
* Mx = Peg INF alpha
**5. Hepatitis E**
* Unenveloped **positive sense ssRNA** genome
* **Acute** infection
* **Faeco-oral** transmission
* RFs = India
* Rare complications: CNS disease e.g. Bell’s palsy, Guillain Barre, other neuropathy
* Mx = supportive
211
# SUMMARY CARD:
What are the susceptible infections in HIV based on CD4+ count:
1. CD4+ < 500
2. CD4+ < 200 (NOTE: this is considered AIDS)
3. CD4+ < 100
**1. CD4+ < 500**
* **EBV** (hairy leukoplakia)
* `HHV-8` (Kaposi sarcoma)
* **HPV** (SCC)
* **Candida** (thrush)
**2. CD4+ < 200 (NOTE: this is considered AIDS)**
* `JC virus` (reactivation = **progressive multifocal leukoencephalopathy**)
* `Pnuemocystitic jeroveci` (**pneumonia**)
* Histoplasma capsulatum (systemic Sx)
**3. CD4+ < 100**
* Bartonella **henselae** (cat scratch disease)
* Nontuberculous mycobacteria (lymphadenitis)
* **CMV** (colitis, `retinitis`, oesophagitis)
* `Aspergillus` (haemoptysis, pain, fever)
* `Candida` (oesophagitis)
* `Cryptococcus neoformans` (meningitis)
* `Cryptosporidium parvum` (severe non-bloody darrhoea; Kinyoun acid fast stain)
* **Toxoplasma** (brain abscess)
212
# SUMMARY CARD:
What are the susceptible infections in the following immunocompromised states:
1. Cystic fibrosis
2. Sickle cell disease
3. Splenectomy
**1. Cystic fibrosis**
* `Aspergillus` fumigatus
* `Burkholderia` cepecia (CI for lung transplant)
* Pseudomonas aeruginosa
* Mycobacterium abscessus
**2. Sickle cell disease**
* `Salmonella` typhi (osteomyelitis)
**3. Splenectomy**
* `NHS` = neisseria meningitides, haemophilus influenzae, streptococcus pneumoniae
213
# SUMMARY CARD:
What are the following features of **HIV**:
1. Structure
2. Entry
3. Sx / antibodies
4. Management
**1. HIV structure**
* 2 copies of a `ssRNA` genome within a conical capsid of p24 (which is surrounded by a matrix of viral protein p17)
* Viral envelope contains glycoproteins **gp120** and **gp41**
* `Pol gene` encodes for reverse transcriptase, integrase and HIV protease
**2. HIV entry**
* HIV can infect **CD4 T cells, macrophages and dendritic cells**
* Gp120 binds to CD4 and `CXCR4` on T cells and CD4 and `CCR5` on macrophages
* NOTE: mutations in CCR5 can give immunity to HIV
**3. HIV Sx / antibodies**
* Sx = glandular fever-like illness
* Ix = HIV antibodies using **ELISA** first, confirmed by `Western Blot`
* **p24** antigen positive from 1 week to 3-4 weeks after infection
* Standard Ix for diagnosis = combination of antibodies + p24 antigen
**4. Management**
* 2 NRTIs + 1 NNRTI / PI
* **Entry inhibitors** e.g. maraviroc (binds to CCR5) or enfuvirtide (binds to gp41)
* Nucleoside analogue reverse transcriptase inhibitor (**NRTI**) e.g. `zidovudine` (SE = anaemia), `tenofovir` (recommended NRTI)
* NOTE: SEs of NRTIs = peripheral neuropathy, black nails
* Non-nucleoside reverse transcriptase inhibitors (**NNRTI**) e.g. `nevirapine` (P450 enzyme inducer)
* **Protease inhibitors** (`-navir`) e.g. ritonavir (potent inducer of P450 system)
* **Integrase inhibitors** (`-gravir`) e.g. raltegravir (blocks integrase, the enzyme that inserts viral genome into DNA of host cell)
214
# DISEASE:
40M - `purple papules + plaques on his skin and oral mucosa`
PMHx = `HIV-positive` w/ poor compliance to HAART
Recent onset of cough and haemoptysis
CXR = pleural effusion
* Which virus is most likely associated with his condition?
* What is the appropriate management?
`HHV-8 (Kaposi sarcoma)` = a type of cancer that forms in the lining of blood vessels and lymph vessels
Sx = **reddish purple skin lesions**, in the lungs can cause **SOB + haemoptysis**
Mx = `radiotherapy and resection`
215
# DISEASE:
35M - progressively worsening `blurred vision bilaterally`
PMHx = `HIV-positive` w/ poor compliance to HAART
Fundoscopy = **retinal hemorrhages** and areas of **necrosis** resembling a "`pizza`" appearance
* Diagnosis? (virus)
* Mx?
`CMV retinitis`
Mx = **IV ganciclovir** (1st line)
216
# DISEASE:
Patient undergoing allogeneic stem cell transplantation requires a blood transfusion
All blood products are routinely screened for HIV, Hepatitis B and C
* What other virus must be screened for in the donor blood products prior to giving it to this patient?
* What Sx can this virus cause in the immunocompromised?
`CMV`
(affects esp. `transplant patients`)
Sx in immunocompromised = encephalitis, retinitis, pneumonitis, colitis, marrow suppression, **oesophagitis** (`LINEAR` ulcers)
217
# DISEASE:
Presence of atypical lymphoycytes on a peripheral blood film suggests what diagnosis?
`EBV`
Ix for EBV:
* **Blood film** = `atypical lymphocytes peripherally` - stretched out cytoplasm
* EBV **serology**
* Monospot agglutination (AKA **heterophile antibody test** AKA Paul-Bennell test) = diagnostic
218
# DISEASE:
What is the triad of Sx seen in EBV?
BONUS: what is the rash from penicillin reaction in EBV called?
BONUS 2: what cancer does EBV predispose in the immunocompromised?
**TRIAD** of `fever + pharyngitis + lymphadenopathy`
BONUS: `morbilliform eruption` (widespread maculopapular rash)
BONUS 2: As EBV can lie dormant in B-cells, it predisposes to `Burkitt’s lymphoma`
Mnemonic: `BBB` → E`B`V, resides in `B` cells, predisposes to `B`urkitt’s lymphoma
219
# DISEASE:
25F - new sexual partner
Painful `genital ulceration`, fever, dysuria, malaise, + inguinal lymphadenopathy
O/E - vesicular rash in the affected area
* Which virus is most likely responsible for her symptoms?
* What is the appropriate treatment?
BONUS: what type of oesophageal ulcers can it cause in the immunocompromised?
**HSV-2** (causes genital ulcers)
Mx = `aciclovir`
BONUS: in the immunocompromised it can cause **oesophagitis** with `CIRCULAR` ulcers (unlike CMV which causes linear ulcers)
NOTE: HPV genital warts are usually painless, without ulceration
220
# DISEASE:
60F - **painful**, vesicular **rash** on the left forehead extending to the nose (following `dermatomal` distribution)
Fever, headache + **reduced vision in her left eye**
1. Diagnosis (+ virus)?
2. Mx?
BONUS: complications?
| Ramsay hunt syndrome; opthalmic herpes zoster
**Shingles** (`VZV`)
Mx = `aciclovir`
Complications:
* Eye involvement = `opthalmic herpes zoster`
* Facial palsy (unilateral facial drooping) + vesicles in ear = `Ramsay hunt syndrome`
221
# DISEASE:
55M - `progressive weakness in his limbs` and difficulty walking
PMHx = `HIV/AIDs`
Brain MRI = multiple white matter lesions
LP + PCR = `JC virus DNA`
* Diagnosis?
* Mx?
`Progressive multifocal leukoencephalopathy (PML)`
no specific Mx for JC virus → supportive care + optimal HAART for HIV
222
# DISEASE:
Which organ does the BK virus primarily affect in the immunocompromised?
Lies dormant in the kidneys → `BK nephropathy`
Mx = **Cidofovir**
NOTE: BK virus = human polyomavirus
223
# DISEASE:
What is the medication given to treat influenza?
Oseltamivir (neuraminidase inhibitor)
224
# DISEASE:
Which hepatitis is chronic?
How is it spread?
Hepatitis `C` (for `c`hronic)
Spread via infected blood e.g. sharing needles, blood transfusions
225
# DISEASE:
Interpret the following HBV serology:
HBsAg = +ve
Anti-HBs = -ve
Anti-HBc IgM = +ve
Anti-HBc IgG = -ve
Anti-HBe = +ve
`Acute infection + high infectivity`
HBsAg +ve = current infection
Anti-HBc `IgM` +ve and IgG -ve = acute infection
Anti-HBe +ve = high infectivity
226
# DISEASE:
Which are the acute Hepatides and how are they transmitted?
```
Hep A + E
faeco-oral
```
227
# DISEASE:
What are some CNS complications of Hep E?
Bell’s palsy, Guillain Barre
228
# DISEASE:
Mutation in what can be protective against HIV?
Mutations in CCR5 can give immunity to HIV
NOTE: HIV infects macrophages via CCR5
229
# DISEASE:
* Which gene in HIV codes for: reverse transcriptase, integrase and HIV protease?
* How is HIV diagnosed?
* Pol gene
* ELISA Anti-HIV antibodies = screening (NB: unreliable in babies as IgGs maybe passed vertically)
* Western Blot = confirmatory (15-45 days since infection)
* Viral load using PCR = very sensitive
* Flow cytometry for CD4 count (< 200 = AIDS)
* ART resistance assays
230
# DISEASE:
How is HIV managed?
* **HAART** = 3+ ART drugs needed
* Usually: `2 NRTIs + 1x NNRTI OR boosted PI`
* Indications for immediate HAART = SYMPTOMATIC, CD4+ < 200 cells/ul, consider if CD4 between 200 and 350
Nucleoside reverse transcriptase inhibitors (**NRTI**) e.g. Zidovudine/Abacavir (OR nucleo`t`ide RTI e.g. `tenofovir`)
**NNRTI** e.g. `efavirenz`
Boosted **PI** e.g. `ritonavir`
2nd line = integrase inhibitors (-gravir)
2nd line = entry / attachment inhibitors (e.g. maraviroc)
2nd line = fusion inhibitors (e.g. enfuvirtide)
231
# DISEASE:
Niche:
Pt on HAART for HIV taking abacavir (NRTI) + tenofovir (NRTI) + efavirenz (NNRTI)
HOWEVER, their HTN is poorly managed on amlodipine
WHY?
Due to efavirenz being a P450 inducer
232
# SUMMARY CARD:
What is the MOA (+ AEs) of the following anti-virals:
1. Aciclovir
2. Ganciclovir
3. Ribavirin
4. Amantadine
5. Oseltamivir
6. Foscarnet
7. Interferon-α
8. Cidofovir
**1. Aciclovir**
* `Guanosine` analogue, phosphorylated by thymidine kinase
* Inhibits the **viral** `DNA polymerase`
* Used to Mx `HSV, VZV`
* **AE = crystalline nephropathy**
**2. Ganciclovir**
* `G`uanosine analogue, phosphorylated by thymidine kinase
Inhibits the **viral** `DNA polymerase`
* Used to Tx `CMV`
* AE = myelosuppression / agranulocytosis
**3. Ribavirin**
* `Guanosine` analogue that inhibits inosine monophosphate (IMP) dehydrogenase → interferes with the capping of viral mRNA
* Used to Tx chronic `hepatitis C`, `RSV`
* AE = haemolytic anaemia
**4. Amantadine**
* Inhibits uncoating (M2 protein) of virus in cells
* Also releases dopamine from nerve endings
* Used to Tx Parkinson's, influenza
* AEs = confusion, ataxia, slurred speech
**5. Oseltamivir**
* Inhibits **neuraminidase**
* Used to Tx `Influenza`
**6. Foscarnet**
* Pyrophosphate analogue which inhibits viral DNA polymerase
* Used to Tx `CMV, HSV` if not responding to aciclovir
* AEs = nephrotoxicity, hypocalcaemia, hypomagnasaemia, seizures
**7. Interferon-α**
* Human glycoproteins that inhibit synthesis of mRNA
* Used to Tx `chronic hepatitis B & C, hairy cell leukaemia`
* AEs = flu-like symptoms, anorexia, myelosuppression
**8. Cidofovir**
* Acyclic nucleoside phosphonate
* NOTE: it is therefore independent of phosphorylation by viral enzymes (compare and contrast with aciclovir/ganciclovir)
* Used to Tx `CMV retinitis in HIV`
* AE = nephrotoxicity
233
# DISEASE:
25F - painful vesicular rash on her lip
She has had similar episodes in the past
?recurrent herpes simplex infection
* Most appropriate antiviral Mx?
Aciclovir
234
# DISEASE:
30M - HIV-positive patient
Diagnosed with cytomegalovirus (CMV) retinitis
* Most appropriate antiviral Mx?
Cidofovir (or ganciclovir)
235
# SUMMARY CARD:
How can gram +ve pathogens be split?
What are some gram +ve pathogens?
| HINT: into cocci + rods
1. **Cocci**
`Catalase +ve` = **staphylococcus**
* **Co-agulase +ve** = staphylococcus `aureus`
* **Co-agulase -ve** = staphylococcus `saprophyticus`, `epidermidis`
`Catalase -ve` = **streptococcus** → blood agar
* **Alpha haemolytic** (PARTIAL haemolysis - green agar) = streptococcus `pneumoniae` (optochin sensitive), streptococcus `viridans` (optochin resistant)
* **Beta haemolytic** (COMPLETE haemolysis) = streptococcis `pyogenes` (GAS, bactracin sensitive), streptococcus `agalactaei` (GBS, bacitracin resistant)
* **Gamma haemolytic** (NO haemolysis) = `enterococcus`
2. **Rods**
* `A`ctinomyles
* `B`acillus cereus
* `C`lostridium
* `D`iphtheria
* `L`isteria monocytogenes
236
# SUMMARY CARD:
How can gram -ve pathogens be split?
What are some gram -ve pathogens?
| macConkey agar / blood agar
**Growth on MacConkey Agar = YES**
`Lactose fermenter` on MacConkey Agar
* **Indole test +ve** = `Escherichia coli`
* **Indole test -ve** = `Klebsiella pneumoniae`
`Non-Lactose fermenter` on MacConkey Agar
* **Oxidase +ve** = `pseudomonas, vibrio`
* **Oxidase -ve** = `salmonella, shigella, yersinia, proteus mirabilis`
**Growth on MacConkey Agar = NO**
* **Growth on Blood Agar** = `brucella`, `eikenella` (human bite), `pasteurella` (dog bite)
* **No growth on Blood Agar** = `haemophilus`
237
# SUMMARY CARD:
Another gram -ve bacteria diagram:
**Cocci:**
* Neisseria meningitides, gonorrhoea
* Moraxella cararrhalis
**Coccobacilli:**
* Haemophilus influenzae, ducreyi
* Bordetella pertussis
* Pseudomonas aeruginosa
* Chlamydia trochamatis
**Rods:**
* Enterobacteriacaea
* Escherichia coli
* Salmonella
* Shigella
* Klabsiella
* Yersinia
**Spirochaetes:**
* Treponema pallidum
* Leptospirosis
* Borrelia
238
# SUMMARY CARD:
What are some obligate intracellular microbes?
| bacteria; protozoa; fungi
**Bacteria:**
* Chlamydia trochamatis
* Rickettsia
* Coxiella (Q fever)
* Mycobacteria laprae
**Protozoa:**
* Toxoplasma
* Cryptosporidium
* Leishmania
**Fungi:**
* Pneumocystitis jeroveci
239
# SUMMARY CARD:
Summary of the antibiotics and what pathogens they cover:
240
# SUMMARY CARD:
What is the MOA (+ indications + SEs) of the following beta-lactam antibiotics:
1. Penicillins (-cillin)
2. Carbapenems (-penem)
3. Cephalosporins
**1. Penicillins (-cillin)**
* E.g. `amoxicillin`, `piperacillin` (against pseudomonas)
* **Broad** spectrum
* Inhibits `transpeptidase`, the enzyme that forms crosslinks during cell wall formation
* Indications = pneumonia, acute otitis media, susceptible infections
* **SEs = GI** (e.g. diarrhoea/vomiting), Morbiliform rash (if given in EBV)
**2. Carbapenems (-penem)**
* E.g. `ertapenem, meropenem`
* **Broad** spectrum
* Inhibits `transpeptidase`, the enzyme that forms crosslinks during cell wall formation
* Indications = HAIs
* SEs = injection site reactions, GI ( e.g. diarrhoea/vomiting)
**3. Cephalosporins**
* E.g. `ceftriaxone, cefalexin`
* **Broad** spectrum
* Inhibits `transpeptidase`, the enzyme that forms crosslinks during cell wall formation
* Indications = meningitis
* SEs = Low toxicity but GI disturbances common
241
# SUMMARY CARD:
What is the MOA (+ indications + SEs) of the following TAMCO antibiotics:
1. `T`etracyclines (-cycline)
1. `A`minoglycosides
1. `M`acrolides (-mycin)
1. `C`hloramphenicol
1. `O`xazolidinones (-zolid)
| TA= 30S, MC = 50S, O = 23S of 50S
1. `T`**etracyclines (-cycline)**
* E.g. `doxycycline, lymecycline`
* **Broad** spectrum
* Bind to the `30S` subunit of ribosomes
* Indications = mycoplasma, rosacea, acne, lyme disease
* AEs = **Teratogenic** + light-sensitive rash, **contraindicated in < 12 y/o** due to teeth discolouration
1. `A`**minoglycosides **
* E.g. `gentamicin, amikacin`
* Gram **-ve** and/or anaerobes
* Bind to `30S` ribosomal subunit, preventing elongation of polypeptide chain
* Indications = meningitis, endocarditis, acute pyelonephritis, catheter-associated UTI
* SEs = **ototoxic + nephrotoxic**
1. `M`**acrolides (-mycin)**
* E.g. `azithromycin, clarithromycin`
* Gram **-ve**
* Bind to the `50S` subunit of ribosomes
* Indications = mild staph/strep infection `if allergic to penicillin`, specifically useful against **Campylobacter + Legionella**
* SEs = nausea (especially erythromycin), P450 inhibitor, **prolonged QT interval**
1. `C`**hloramphenicol**
* Potent broad-spectrum antibiotic
* Indications = conjunctivitis, plague (Causes dry gangrene slowly)
1. `O`**xazolidinones (-zolid)**
* E.g. Linezolid
* Binds to the `23S` portion of the `50S` ribosome subunit to prevent `70S` subunit formation
* Indications = highly active against **gram +ve** organisms - especially MRSA and VRE
* SEs = thrombocytopaenia + neurological side effects
242
# SUMMARY CARD:
What is the MOA (+ indications + SEs) of the following antibiotics:
1. Glycopeptide
2. Nitroimidazoles (-dazole)
3. Fluoroquinolone (-floxacin)
4. Sulfonamides (-xazole)
**1. Glycopeptide**
* E.g. `vancomycin, teicoplanin`
* Gram **+ve**
* inhibits cell wall formation by binding to D-Ala-D-Ala moieties, preventing polymerisation of peptidoglycans
* Indications = **MRSA** infection
* SEs = **Nephrotoxic**; `Red man syndrome` (on rapid infusion)
**2. Nitroimidazoles (-dazole)**
* E.g. `metronidazole, tinidazole`
* Anaerobes + Protozoa
* Under anaerobic conditions, an active intermediate is produced which causes DNA strand breakage
* Indication = **anaerobic** infections, **H.pylori** eradication, **BV / TV, PID**
* SEs = dry mouth, myalgia and nausea; disulfiram reaction w/alcohol
**3. Fluoroquinolone (-floxacin)**
* E.g. `levofloxacin, ciprofloxacin`
* **Broad** spectrum
* Act on alpha subunit of DNA gyrase
* Indication = UTI, pneumonia, bacterial gastroenteritis, neutropenic sepsis prophylaxis
* SEs = GI disturbances (C.difficile infection), CNS disturbances
**4. Sulfonamides (-xazole)**
* `Sulfamethoxazole` (component of co-trimoxazole)
* **Broad** spectrum
* Inhibiting dihydropteroate synthetase
* Indications = **pneumocystis jirovecii** (co-trimoxazole)
* SEs = hyperkalaemia, headache, SJS rash
243
# DISEASE:
What are the MOAs for TAMCO?
1. `T`etracyclines (-cycline) = 30S
1. `A`minoglycosides = 30S
1. `M`acrolides (-mycin) = 50S
1. `C`hloramphenicol = 50S
1. `O`xazolidinones (-zolid) = 23S + 50S → 70S
244
# DISEASE:
22F - sore throat, fever, and difficulty swallowing
Dx = **streptococcal** pharyngitis
* Which abx is most appropriate?
Penicillins e.g. amoxicillin
245
# DISEASE:
45M - Admitted to the hospital with sepsis
Causative organism = **MRSA**
* Which abx is most appropriate?
Vancomycin
246
# DISEASE:
30F - UTI caused by pseudomonas aeruginosa
* Which abx is most appropriate?
Piperacillin (+ tazobactam)
247
# DISEASE:
28M - returned from hiking trip
Sx = fever, headache, bull's eye rash
Dx = **Lyme disease**
* Which abx is most approrpiate?
Doxycycline
248
# DISEASE:
35F - lower abdominal pain + foul-smelling vaginal discharge
Microscopy - **flagellated protozoa**
* Which abx is most appropriate?
Metronidazole (Dx = TV)
249
# SUMMARY CARD:
What is the typical organism + abx used at each of the following sites:
1. Skin
2. Pharyngitis
3. CAP
4. HAP
5. Bacterial meningitis
6. UTI
7. Sepsis
8. Colitis
1. **Skin** → *S. aureus* → `flucloxacillin`
2. Pharyngitis → beta-haemolytic strep → `benzylpenicillin`
3. **CAP** → mild = `amoxicillin`; moderate = `amoxicllin + clarithromycin`
4. H****AP → severe = `co-amoxiclav + clarithromycin`
5. **Bacterial meningitis** → *meningococcus / streptococcus* → `Ceftriaxone` (+ amox/ampicillin for young/old for listeria cover)
6. **UTI** → community → `trimethoprim / nitrofurantoin` (if HAI = co-amoxiclav or cephalexin)
7. **Sepsis** → severe → `tazocin / ceftriaxone, metronidazole + gentamicin` (if neutropenic then tazocin + gentamicin)
8. **Colitis** → *C. diff* → `metronidazole` or `vancomycin`
250
# SUMMARY CARD:
What microbes are the following stains used to detect?
1. Giemsa
2. India ink
3. Periodic acid-Schiff stain
4. Silver stain
5. Ziehl-Neelsen
6. Auramine-Rhodamine
7. Kinyoun Acid Fast
8. Field’s stain
**1. Giemsa**
* Nuclei stain purple, cytoplasm stain blue to pale pink, eosinophils stain orange
* `Trypanosomes` (e.g. Trypanosoma brucei, Trypanosoma cruzi, `Leishmania` spp)
* `Chlamydia`
* Cytomegalovirus (`owl-eye` viral inclusions)
**2. India ink**
* `Cryptocccus neoformans` (**halo** sign)
**3. Periodic acid-Schiff stain**
* `Candida`
* Tropheryma whippelii (AKA **Whipple's disease**) shows deposition of macrophages
**4. Silver stain**
* Pneumocystis jiroveci
* Legionella pneumophilia
* Helicobacter pylori
* Aspergillus
* HIV
* NOTE: the **methenamine silver stain** is used for FUNGI e.g. `pneumocystitis, candida, aspergillus`
**5. Ziehl-Neelsen**
* `Acid fast bacilli` turn `red`, if not, stain remains blue
* Mycobacterium `tuberculosis`
* `Cryptosporidium` spp.
**6. Auramine-Rhodamine**
* `Mycobacterium` = `red/yellow`
* Not as specific as ZN stain, but more affordable and more sensitive
**7. Kinyoun Acid Fast**
* AKA modified ZN test
* `Cryptosporidium parvum` (causes diarrhoea in immunocompromised)
**8. Field’s stain**
* Stain is made up of Methylene blue + Eosin Y
* `Plasmodium` (thick blood films)
251
# SUMMARY CARD:
What are some tests for the following **fungal infections**:
1. Tinea / trychophyton
2. Cryptococcus
3. Pneumocystitis
4. Candida
5. Aspergillus
6. Histoplasmosis
| think stains, antigens etc.
NOTE: `gold standard` for **fungal infections** is `culture`, however, takes many weeks to grow so these tests can be done in the mean time:
**1. Tinea / trychophyton** = `KOH` mixed with nail clippings
**2. Cryptococcus** = `India` ink stain, `glucuronoxylomannan` antigen test
**3. Pneumocystitis** = `periodic acid-schiff (PAS)` stain or silver stain, `beta-D-glucan` antigen test
**4. Candida** = methenamine `silver stain` or `PAS`, `beta-D-glucan` antigen test
**5. Aspergillus** = methenamine `silver stain` or `PAS`, `galactomannan` antigen test
**6. Histoplasmosis** = fungal serology
252
# DISEASE:
Guess the microbe seen with the following stains:
1. Owl eyes on Giemsa stain
2. KOH with nail clippings
3. Zielh-Neelson - turns red
4. Kinyoun acid fast
5. Auramine-rhodamine - turns bright yellow
6. Field's stain
7. Methenamine silver
8. Periodic acid-Schiff stain
9. India-ink with halo sign
10. Beta-D-glucagon antigen
11. Galactomannan antigen
12. Glucoronoxylomannan antigen
1. **CMV**
2. **Tinea** / trychophyton
3. **Mycobacterium** tuberculosis
4. **Cryptosporidium** parvum
5. **Mycobacterium** tuberculosis
6. **Plasmodium** (thick film)
7. Pneumocystitis, candida, aspergillus
8. **Candida**, pneumocystitis, aspergillus, whipple's disease
9. **Cryptococcus** neoformans
10. Pneumocystitis, candida
11. Aspergillus
12. Cryptococcus
253
# SUMMARY CARD:
What microbes are grown on the following agars:
1. Buffered charcoal yeast extract
2. Bordet-Gengou (potato) agar
3. Eaton Agar
4. Chocolate agar
5. Thayer Martin media (chocolate agar variant)
6. Castaneda medium
7. Lowenstein Jensen media
8. Blood agar
9. MacConkey agar
10. Czapek Dox Agar
11. Novy-Macneal-Nicolle medium
12. Sabouraud agar
| Nice Homes have chocolate; * Lactating pink monkeys; BORDETella
**1. Buffered charcoal yeast extract** = `legionella` pneumophila
**2. Bordet-Gengou** (potato) agar = `bordetella` pertussis
**3. Eaton** agar = `mycoplasma` pmeumoniae
**4. Chocolate** agar = `haemophilus` influenzae, haemophilus ducreyi
**5. Thayer Martin** media (chocolate agar variant) = `neisseria` meningitidis, neisseria gonorrhoeae
**NOTE**: for thayer-martin, add vancomycin (inhibits Gram positives) + polymyxin (inhibits gram negatives) + nystatin (inhibits fungi)
**6. Castaneda** medium = `brucellosis`
**7. Lowenstein Jensen** media = mycobacterium species → brown coffee coloured (buff), bread-crumb like (rough), sticks to bottom of growth plate (tough) = `Mycobacterium tuberculosis`
**8. Blood agar** = alpha haemolytic (green agar - partial) = `streptococcus` pneumoniae + viridans; beta haemolytic (pale agar - partial) = GAS, GBS
**9. MacConkey** agar = `pink` with lactose fermenters e.g. `E.coli, Klebsiella, Enterobacter`
**10. Czapek dox** agar = `aspergillus`
**11. Novy-Macneal-Nicolle** medium = `leishmania`
**12. Sabouraud** agar = `fungi`
13. Tellurite agar or **Loeffler's** media = corynebacterium `diptheriae`
Year 5: Pathology
flashcards
Decks in class (7)
# Cards
