Micro - Specific Groups Affected Flashcards

Question

Foetal/Neonatal Diagnosis of CMV

Answer 1

Pre-natal: Detection of CMV DNA in amniotic fluid at 21 weeks gestation Post-natal: - CMV detection within 21 days of life. (Positive result beyond that time will NOT make a diagnosis of congenital infection) - Urine/Salivary swab/blood for CMV PCR - CMV Serology - CMV IgM (low sensitivity)

Answer 2

Vaccine None at present – in development Prevention “universal precautions” ``` Antiviral treatment: - Not used during pregnancy – toxicity Congenital CMV with end organ disease - Valganciclovir / Ganciclovir for 6/12 - Audiology review until age 6 - Ophthalmology review ```

Answer 3

First episode, primary infection - 57% First episode, non-primary infection - 25% Recurrent infection - 2% Symptomatic/Asymptomatic Highest risk = Maternal primary HSV infection in the third trimester. - particularly within 6 weeks of delivery: continuing viral shedding , birth before development of protective maternal antibodies. C-section recommended.

Answer 4

Type of maternal infection Maternal antibody status (neutralizing Ab) Duration of rupture of membranes Integrity of mucocutaneous barriers (eg use of foetal scalp electrodes) Mode of delivery (caesarean section versus vaginal) Highest risk of transmission is in the permpartum(perinatal period) - 85% (as opposed to 5% in utero and 10% postpartum).

Answer 5

- Decrease the time to diagnostic consideration (mum&baby) - Early initiation of antiviral therapy - Prompt collection of specimens for diagnosis - HSV cultures/PCR, liver transaminase levels (suggest disseminated HSV infection) Rx: - High dose aciclovir at 60 mg/kg/day IV in three divided daily doses - Continute for 21 days in CNS/disseminated, 14 in SEM - Continue acyclovir until PCR -ve - Monitor neutrophil count and renal function

Answer 6

- DNA virus - HHV3 - Droplet transmission - 90% women of childbearing age immune - Spread through local nerves with latency in the sensory dorsal root ganglia - Zoster (shingles) - no risk to the foetus Foetus - risk of transmission: - Congenital varicella syndrome - Neonatal varicella - Herpes zoster in early childhood Mother: pneumonitis, encephalitis, sepsis

Answer 7

Eyes: - Chorioretinitis - Cataracts Neurological: - Microcephaly - Cortical atrophy Musculoskeletal/Skin: - Limb hypoplasia - Cutaneous scarring Other: - IUGR Maternal infection during 13-20 weeks' gestation = highest risk (2%)

Answer 8

Newborn is vulnerable when maternal infection occurs within 7 days prior to delivery or 7 days post-partum - No time for passive transfer of VZV antibodies Manifestations of infection may include - Mild course of infection - Disseminated skin lesions - Purpura fulminans - Visceral infection - Pneumonitis 20% mortality untreated Diagnosis: clinical or VZV PCR of lesion

Answer 9

Vaccine: Live virus vaccine available (give preconception) Avoidance of exposure in pregnancy if susceptible Post-exposure prophylaxis: - Varicella-zoster immunoglobulin (given with 10 days of exposure) up to 20/40 - Antiviral chemotherapy: Aciclovir 800mg x4/day from day 7-14 post exposure after 20/40

Answer 10

- Unique tropism for rapidly dividing erythrocyte precursors - Virus requires the P blood antigen receptor (globoside) to enter the cell - Suppression of erythrogenesis - No reticulocytes are available to replace aging or damaged erythrocytes as they are cleared by the reticuloendothelial system - Virus crosses the placenta and destroys red cell precursors - Foetal anaemia --> high output congestive heart failure --> hydrops fetalis - Virus also directly infects and injures myocardial cells

Answer 11

Maternal Infection: - Parvovirus DNA PCR from blood (and respiratory samples) - Serology - IgM, IgG, seroconversion Foetal Infection: - Foetal blood and amniotic fluid for serology and Parvovirus PCR

Answer 12

Rare in pregnant women in UK: - Foetal loss (miscarriage, IUD) - Preterm delivery - Increased maternal morbidity - No congenital abnormalities to foetus In susceptible pregnant woman in contact with suspected/confirmed measles: - Measles Immunoglobulin attenuates illness - No evidence it prevents IUD or preterm delivery - MMR cannot be given post exposure in pregnancy (live vaccine)

Answer 13

- 80% of infections asymptomatic - Miscarriage/stillbirth/microcephaly - Associated predominantly with travel to Caribbean/Central/South America (Antigua, Barbados, Grenada, Jamaica, St Lucia & Trinidad & Tobago) Congenital Zika Syndrome: - Severe microcephaly + skull deformity - Decreased brain tissue, subcortical calcification - Retinopathy, deafness - Talipes, contractures - Hypertonia Current Advice: - Bite avoidance - Avoid travel to all areas with current transmission - Avoid conception 3 months after travel (prolonged viral shedding in semen) - Testing only in symptomatic or abnormalities identified on antenatal USS - Abnormalities commonly detected in late 2nd or 3rd trimester

Answer 14

- Of the 35.3 million people living with HIV in Dec 2012, 1/10 are children - Large impact of AIDS on under 5 mortality in African countries - HIV accounts for 35% of deaths of children <5 in SSA. Trend however is towards increasing proportion of deaths in teenagers with perinatally acquired HIV. - HIV in children: >90% is due to mother-to-child transmission but child sexual abuse or exchanging sex for food/shelter = risk factors for vulnerable children (i.e. orphaned etc) - 1/3 of babies born to mothers with HIV who did not know their diagnosis, born by normal vaginal delivery and breast fed for 1 year/18 months will be infected (on a population level)

Answer 15

- Progressive encephalopathy - basal ganglia calcification, white matter changes, atrophy (v large ventricles), vasculopathy/strokes. Neurotrophic virus. - Anaemia - Frequent nose bleeds - Severe oral thrush - Suppurative ear infections - Enlarged parotids - Failure to thrive - Lymphadenopathy - Severe pneumonia - TB, VZV, pneumocystis carinii, LIP (lymphoid interstitial pneumonitis - CXR looks like TB but child clinically much more well. Lymphoid tissue between airways contracts --> airway stretched --> bronchiectasis --> chronic suppurative lung disease and clubbing as result) - Hepatosplenomegaly - Clubbing - Severe nappy rask - Recurrent or persistent diarrhoea - Easy bruising (thrombocytopenia) - Herpes zoster infection - worry if in more than one dermatome. Trigeminal shingles is almost pathopneumonic of HIV in an endemic area. - Molloscum very common - Spinal TB - Pott's disease - CMV --> blindness (spread perinatally) - Kaposi's (most die or something else before they die of malignancy)

Answer 16

- Vertical transmission: breast feeding, in utero, perinatal. % transmission increases significantly with increasing maternal plasma viral load. - A healthy placenta is an effective barrier to transmission of HIV from mother to baby (Also Hep B and C) - Most transmission occurs towards the end of of pregnancy when the placenta is getting tired alongside maternal uterine contractions --> microhaemorrhages allow maternal blood to get into foetal circulation. - Birth canal plays key role. --> first born twin has double the risk of being infected, as it’s born it clears the birth canal of cervico-vaginal secretions, also more susceptible to ascending infections once the waters have broken. - Elective C section halves risk of transmission - 16% increased with breast vs formula feeding

Answer 17

All pregnant and BF women should initiate triple ARVs - Fixed dose combination Tenofovir+3TC+efavirenz - BF infants should receive daily NVP for 6 weeks Maintain ARVs for duration of MTCT risk Maintain ARVs lifelong with those meeting Rx eligibility (CD4< 500) (strong recommendation) Maintain ARVs lifelong in all for programmatic reasons (conditional recommendation) Uninfected infants should exclusively BF for 6 months and continue to BF until atleast 12 months In developing countries where access to HRT is not as easy, bigger focus on prevention/reducing transmission etc.

Answer 18

other infections can flare up as you start to treat the immune system

Answer 19

- Steroids - Calcineurin inhibitors (T-cell function) - cyclosporin, tacrolimus - Antiproliferative agents - azathioprine - Antibodies - depleting, non-depleting (anti CD-25 receptor ABs, costimulation blockers - belatacept)

Answer 20

Viruses acquired from graft eg HBV - Serostatus - Risk assessment Viral reactivation from the host eg HSV - Serostatus - Monitoring - Prophylaxis - Pre-emptive therapy ``` Novel infection from infected individual eg VZV - Isolation-barrier nursing - Advide for family/contacts - PEP - Vaccinating contacts - Control of diet ```

Answer 21

``` Pre-transplant serology: HIV Ag/Ab HBV sAg HBV cTAb HBV sAb HCV Ab EBV IgG CMV IgG HSV IgG VZV IgG HTLV Ab ``` ``` Post transplant: CMV monitoring or prophylaxis EBV monitoring Adeno monitoring (paeds BMT) HSV prophylaxis if indicated ```

Answer 22

Opportunistic viral infections are often more difficult to treat Often requires - Early treatment - higher dose - longer course - sometimes drug combinations Increased risk of antiviral drug resistance

Answer 23

- Acute retinal necrosis (ARN) - Progressive outer retinal necrosis (PORN) - VZV-associated vasculopathy

Answer 24

Encephalitis Retinitis Pneumonia Gastroenteritis In transplant the risk of CMV disease relates to pre-tx serostatus - solid organ transplant - D+/R- : carries the greatest risk of reactivation - bone marrow transplant: adoptive immunity - D-/R+ : carries the greatest risk of reactivation Prevention strategies: - BM - CMV viral load twice weekly, treat if virus reactivates until suppressed (pre-emptive therapy) - Solid organ - Valganciclovir prophylaxis for 100 days ``` Rx: Ganciclovir (IV): bone marrow suppression Valganciclovir: oral Foscarnet (IV) (nephrotoxicity) Cidofovir (nephrotoxicity) IVIg (with another drug for pneumonitis) ```

Answer 25

Post-transplant lymphoproliferative disease (PTLD) - Latently infected B cells – polyclonal activation - Predisposes to lymphoma - suspicion on rising EBV viral load (> 105 c/ml) and CT scan - Confirmation with biopsy of lymph nodes

Answer 26

HAART, radiotherapy, surgical, INF alpha, chemo

Answer 27

- Plyomavirus - Effective antiretroviral therapy has drastically reduced PML incidence in HIV+ve patient - Can be seen in other types of immunosupressed hosts: i.e patients on monoclonal antibodies - Cognitive disturbance, personality change, motor deficits other focal neurological signs - The main pathological feature of PML is a demyelination of white matter with neurological deficits corresponding to the area(s) of the brain affected - Diagnosis: MRI and PCR on CSF

Answer 28

Polyomavirus Double stranded DNA BK cystitis post SCT BK nephropathy post Renal Tx

Answer 29

- Particular problem post-BMT (especially paeds) - Exogenous infection or reactivation of persistent endogenous infection. - Fever - Encephalitis/Pneumonitis/Colitis - High mortality with disseminated infection.

Answer 30

Increased risk of complications (pneumonitis) and high mortality associated particularly with: - Influenza A and B - Parainfluenza 1, 2, 3 and 4 - Respiratory Syncitial Virus (RSV) infection - Adenovirus - Novel coronavirus: MERS coronavirus ``` Rx: Influenza A and B - Oseltamivir (oral drug) for 5 days - If severely immunosupressed: risk of oseltamivir resistance - zanamivir (inhalation or IV) is an alternative ``` Other respiratory viruses do not have a standard treatment protocol

Answer 31

Two things can happen: 1) Carriers may have flare of disease. 2) Those who have had past infection can reactivate --> The risk of reactivation is particularly important with patients on B-cell depleting therapies (i.e Rituximab) Prevention: Nucleoside/nucleotide analogues (eg lamivudine, tenofovir, entecavir) prophylaxis (Hep E also more common)

Answer 32

Healthcare associated infections Timing- onset within a certain period from contact; not present on admission If not present on admission – possibly acquired in hospital Categorise- by organism / by syndrome 15-30% likely reversible

Answer 33

Around 8% | Most common in intensive care

Answer 34

Pneumococcal pneumonia

Answer 35

``` GI Urinary tract Pneumonias Surgical site Skin and soft tissues ```

Answer 36

Gram +ve spore forming anaerobe | C. diff colitis associated with abs use

Answer 37

Grav -ve rod

Answer 38

Wound environment Host defences Pathogens

Answer 39

Carbapenemase-producing Enterobacteriaceae e.g. NDM klebsiella pneumoniae

Answer 40

Petersdorf 1961 - Fever >38.3C - Lasting > 3 weeks - Uncertain diagnosis after 7 days in hospital Durack 1991 - Prescriptive set of mandatory investigations - 3 days of hospital investigation or 3 OP visits Knockaert 2003 - Pragmatic - 3 days of Hospital investigation with no diagnosis

Answer 41

Children – - 44% infective - 43% undiagnosed HIV - CD4 cell count dependent - High risk of TB and NTM - PCP - Cryptococcal meningitis - Non-Hodgkin's lymphoma Neutropenia - Underlying disease - Fungal infections

Answer 42

Hx: - B-symptoms, localising clues - Medications - doses and initiation date - Foreign travel - be exact! What did they do there? Where where they? For how long? - Unwell contacts, pets / animal exposures, injecting drug use, sexual history Ex - really thorough top to toe examination, look everywhere you can.

Answer 43

Routine Admission Ix: - FBC - U&E - LFTs - CRP - CXR - Blood cultures - Urine dip Additional Tests - - Essential for PUO: - 2x more blood cultures - Urine culture - Stool cultures x3 and OCP (ova, cysts and parasite) - CMV/EBV serology - HIV/HBV/HCV Additional Tests - if indicated/previous set unremrkable: - CK - Ferritin - LDH - ANA - ANCA - RhF - TFT - FDG-PET CT (Fluro-D Glucose accumulates in cells with an increased rate of glycolysis e.g. activated leukocytes) - Echo - Biopsies - LPs - Bone marrow 1/20 false positive --> the more tests you do, the more will be positive by chance so try to use specific/targeted tests

Answer 44

5-10% of IE have negative blood culturess because of antibiotics or Fastidious organisms (HACEK) or Aspergillus, Bartonella, Brucella, Coxiella, Rickettsia, Mycobacteria, Nocardia, Chlamydia HACEK = Haemophilus, Aggregatibacter, cardiovacterium, Eikenelia, Kingella Initially do TTE. Unless you are sure it is completely benign on TTE/low clinical suspicion, get TOE as well. Clinical - Duke's criteria

Answer 45

Viral - CMV / EBV - HIV - Hepatitis A,B,C,D,E Parasites - Malaria - Amoebic liver abcess - Schistosomiasis - Toxoplasmosis - Trypanosomiasis Fungal - Cryptococcosis - Histoplasmosis - Coccidioides Bacterial - Mycobacteria - TB, NTM - Enteric fevers - Salmonella typhi - Zoonoses Can send off the the panel for certain geographic regions

Answer 46

There are loads - all the vasculidities etc Young patient = Adult onset Stills - salmon pink rash (may be mistaken for drug rash). Ferritin often very high in Adult onset Stills --> Macrophage activation syndrome). Older patient = GCA Involve rheumatologist Careful interpretation of results

Answer 47

Lymphoma - often advanced diseases with aggressive subtype Leukaemia Renal cell carcinoma - 50% present with fever, haematuria can also occur Hepatocellular carcinoma or other tumours metastatic to the liver Often identified on Axial imaging

Answer 48

Subacute thyroiditis Addisons Dressler syndrome PE Habitual hyperthermia - variation in temp in the mentstrual cycle Drug fever - idiosyncratic reaction or by affecting thermoregulation. Accompanying rash and eosinophilia in 25% Factitious fever

Answer 49

70% of those returning from Africa had a tropical illness Risk of tropical infection higher among VFRs (visiting friends and relatives) Non-tropical were common among returnees from SE Asia (45%) - but enteric fever (34%) and dengue (20%) remain important

Answer 50

1) Fever (Systemic Febrile Illness) - Undifferentiated fever, Fever ‘plus’ some localising signs/symptoms 2) Diarrhoea (acute/chronic) 3) Skin Rash (+/- eosinophilia) 4) Respiratory Syndrome

Answer 51

``` P. Vivax P. Ovale P. Malariae P. knowlesi P. Falciparum - Invades erythrocytes of all ages, may be drug resistant and can be life threatening ``` From female anopheles mosquito Africa – causes 20% of childhood deaths African child – 1.6-5.4 episodes in malaria fever each year

Answer 52

Fevers – cyclical or continuous with spikes Malaria paroxysm – chills, high fever, sweats Severe Malaria: High parasitaemia or schizont Altered consciousness with/ without seizures Respiratory distress or ARDS Circulatory collapse Metabolic acidosis Renal failure, haemoglobinuria (blackwater fever) Hepatic failure Coagulopathy +/-DIC Severe anaemia or massive intravascular haemolysis Hypoglycemia

Answer 53

Falcip – double dotted rings (chromatin dots on some rings) Vivax – schuffners dots may be present Malaria – mature schizonts have daisy head appearance. Squarish appearance of ring forms Ovale – enlarged red cells. Comet forms Thick and thin blood smears x3 - Field’s or Giemsa stain - Thick: screen parasites (sensitive) - Thin: identify species & quantify parasitaemia Malaria antigen detection tests - Paracheck-Pf® (detect plasmodial HRP-II) - OptiMAL-IT (parasite LDH)

Answer 54

- Chloroquine – 3 days - Primaquine 30mg for 14 days weeks if G6PD normal Hypnozoites Complications in non-falciparum malaria are extremely rare but splenic rupture is well recorded (80% mortality with splenic rupture)

Answer 55

Not vomiting, Parasitaemia <2%, Ambulant - Oral Malarone ™ (atovaquone and proguanil) - 4 tablets daily with food for three days - ACT – artemisinin combination therapies E.g Riamet/ Co-artem – Artemisinin & Lumefantrine - Oral quinine 600mg tds (salt) - then doxycycline 100mg od for 1 week

Answer 56

- ABC - Correct Hypoglycamia - Cautious rehydration (avoid overload) - Organ support as necessary - IV Artesunate in preference to IV Quinine Quinine side effects: cinchonism, arrhythmias, hyperinsulinaemia - Daily parasitaemia then PO follow on eg with ACT

Answer 57

Organism: Dengue Virus (RNA virus) - flavivirus Transmitted via the Aedes mosquito. Mostly urban disease Presents with: fever, headache, myalgia, rash in 50% 3 Phases: FEBRILE - Day 1-4 – fever, headache, rash CRITICAL - Day 4-7 – bleeding, shock RECOVERY – inflammation. DHF and shock syndromes rare in travellers- Occur in those previously infected with a different Dengue serotype. Investigations: - Serology (IgM 5-7 days), PCR. - Dengue cross reaction with other flavivirus IgG (JE, yellow fever.) Treatment: - Identify those at risk of shock. (High Hct, low platelets) - Supportive - Paracetamol

Answer 58

Organism: Salmonella Typhi/ Paratyphi Vaccine only partially protective vs S.typhi, no cover vs S.paratyphi Symptoms: - Fever - high and prolonged - Headaches - GI symptoms (Payer’s patches) - constipation - “Rose spots” - rare but specific - Hepatosplenomegaly - Dry cough Investigations: Blood and stool culture. Screen for HIV and malaria. Treatment: Empiric Ceftriaxone (2g IV OD) then Azithromycin 500mg BD 7 days Complications: GI bleeding/ perforation/ encephalopathy

Answer 59

Test for EBV - less specific than IgM/IgG

Micro - Specific Groups Affected Flashcards

(83 cards)