Final Exam

Question 1

Dengue virus

type of disease, serotypes, causing agent, prevalence, where its found in the world, s/s, tx, vaccine, dx

Answer 1

• arthropod viral disease
• causes - Aedes aegypti
• # 2 most common arthropod disease after malaria
• “break bone fever”
• don’t have in UT
  
  • emerging threat in Florida
• four distinct serotypes
  
  • DENV-1,2,3,4
• s/s
  
  • asymptomatic to mild flu like symptoms
  • dengue hemorrhagic fever and dengue shock syndromes
    
    • fatality rate 40%
• dx. virus isolation and detect antibodies
• no effective vaccine available
• tx. supportive care
• vector control

Question 2

how many times more likely are HIV victims to develop active TB?

Answer 2

800 times

Question 3

two largest known pandemics that were caused by viruses

Answer 3

• 1918 “spanish flu” pandemic
  
  • killed more than 25 million people in one year (3.6% of worlds population)
• HIV/AIDS
  
  • first recognized in U.S. in early 1980s
  • now worldwide pandemic
  • devastating Africa

Question 4

is the home to % of the world’s people living with HIV

Answer 4

Sub-Saharan Africa

68%

Question 5

hepA vaccine

Answer 5

2 dose series

12-23 mos

Question 6

aerobes vs anaerobes vs facultative anaerobes (oxygen requirements)

Answer 6

• aerobes - require O₂ for metabolism
• anaerobes - do not use O₂ for metabolism (some can tolerate it, but others are killed by it)
• facultative anaerobes - grow better in presence of O₂, but can grow in its absence

Question 7

ways microbes are used that are beneficial to society

Answer 7

• exploited to produce foods
• used to make products (drugs, chemicals, biotechnology) and energy sources (biofuels)
• used for bioremediation to clean-up environmental pollutants

Question 8

Anthrax

type of disease, where it is found, cause, used for what, treatment, varieties,

Answer 8

• soilborne bacterial disease
• cause: Bacillus anthracis (g+ endospore-forming)
• primarily found in grazing animals
• biowarfare
• antibiotics effective against all forms, but early intervention necessary
  
  • vaccine for high risk
• three varieties:
  
  • inhalation anthrax (woolsorter’s disease)
    
    • ​most severe; hazard for people who work with contaminated dead animals; flu-like symptoms
  • cutaneous anthrax
    
    • acquired by contact with wool, hides, leather, hair products
    • s/s - small blisters, ulcer
  • gastrointestinal anthrax
    
    • from ingesting under-cooked meat
• most common in agricultural regions of many countries, but rare in U.S. (sporadic outbreaks)
• vaccination recommended for livestock
• also infected by injecting heroin.. reported in Europe

Question 9

pneumococcal conjugate (PCV13) vaccine

Answer 9

4 dose series

2 mos

4 mos

6 mos

12-15 mos

1 dose >65 yrs

Question 10

Onchocerca volvulus

type of disease, transmission, host, s/s

Answer 10

• roundworm disease
• “river blindness”
• transmission: female blackfly
  
  • larvae migrate to biting parts of fly after development
  • live near muscles and joints (significant pain)
  • produce thousands of larvae daily; adult worms can live up to 15 years in human body
• s/s: corneal inflammation (keratitis), blindness
• humans are only definitive host

Question 11

trichomoniasis

type of disease, microorganism that causes it, prevalence, where its found in the world, reservoir, s/s, tx, dx, carriers

Answer 11

• sexually transmitted protozoan disease
• cause - Trichomonas vaginalis
  
  • flagellated protozoan
• one of the most common STDs; worldwide
• no cyst stage; cannot survive long outside of host
• human urogenital tract is the only reservoir
• many infected are asymptomatic carriers
• s/s - iching, dysuria, discharge
• tx - oral drugs (tinidazole, metronidazole)
  
  • the most treatable STD
• dx - swab then microscope and look for motility

Question 12

Group B strep

s/s, prevention

Answer 12

• primary concern for newborns
  
  • early and late onset
• s/s: fever, difficulty feeding and breathing, blue-ish skin, irritable, streptococcal pharyngitis
• prevention:
  
  • test pregnant women (25% carry)
  • IV antibiotics during labor

Question 13

multicellular microbes

Answer 13

• algae
• fungi

Question 14

antigenic drift vs antigenic shift (influenza)

Answer 14

Question 16

Answer 16

lice

Question 17

Dracanulus medinensis

type of disease, worm that causes it, s/s, tx, portal of entry and exit

Answer 17

• roundworm disease caused by guinea worm
• no symptoms for 1 yr, then flu-like
  
  • blister develops and causes burning pain. bursts with temp change of cool water and thousands of larvae release
• portal of entry: drinking water
• tx. is necessary

Question 18

epidemiologists

Answer 18

challenged to determine why an outbreak of disease occurs at a particular time and/or particular place

Question 19

Noroviruses (Norwalk and Norwalk-like)

genome type, how contagious is it, where outbreaks occur, morbidity rates, what disease does it cause

Answer 19

• +ssRNA (use directly as mRNA)
• very contagious: ID <10 viral particles
• causes inflamed stomach and intestines
• persists in environment; viruses shed after recovery
• very common (millions of cases in U.S. per year)
• cruise ship outbreaks
• “stomach flu”
• prevent by sanitation
• cause gastroenteritis
• foodborne and waterborne virus

Question 20

prevention of TB

Answer 20

• BCG (bacillus Calmette-Guerin) vaccine
  
  • attenuated
  • protection rate ~80% children and <50% in adults; not life-long
  • gives positive TB skin test
  • we don’t use this vaccine
• improve DOTS implementation
• improve social conditions (poverty, water quality, housing)
• improve public health care

Question 21

bacterial contact diseases (other than STDs)

Answer 21

Question 22

reservoirs

Answer 22

• reservoir - site in nature in which microbes survive (and possibly multiply) and from which they may be transmitted
• humans are the only known reservoir for pathogens that cause smallpox, gonorrhea, measles, polio

Question 23

viral genome replication for ssDNA

Answer 23

Question 24

Molecular HIV Surveillance (MHS)

example of when it was used

Answer 24

• a group of people whose HIV genetic sequence is so similar it implies an epidemiological link among them
  
  • called an HIV cluster
• two persons infected with highly similar HIV strains could be directly linked through transmission, but both could…
  
  • have been infected by a third source OR
  • be connected indirectly by 1 or more intermediaries
• Bexar County, San Antonio, Texas
  
  • ​cluster 51 - all men, largely hispanic, MSM, and average age of 29

Question 25

meningococcal vaccine

Answer 25

2 doses 11-12 yrs 16 yrs

Question 26

**La Crosse encephalitis** type of disease, where it occurs in the world, what it can cause

Answer 26

* encephalitis-causing arboviruses * occurs in upper midwestern U.S. (La Crosse, Wisconsin) * can cause miscarriages and deformities

Question 27

indirect transmission

Answer 27

* **indirect transmission** - microbes pass from reservoir to intermediate agent to host * **vehicleborne** - via food, water, biological products (organs, blood), and fomites * **airborne** - aerosols of water or dust (less than 4 µm) that remain airborne for extended periods * **vectorborne** - arthropods (ticks, flies, mosquitoes, lice, fleas) or insects (chagas' kissing bug) * **mechanical** passive transmission on feet; microbes do not invade, multiply, or develop in the vector * **biological vectors** - transmission is an active process

Question 28

pinworms

Answer 28

* life cycle in intestine * emerge at nighttime to lay eggs (10-15,000) * intense itching and nightmares * very infectious

Question 29

**Taeniasis** type of disease, cause, portal of entry, portal of exit, host, s/s, where is it found

Answer 29

* caused by tapeworms - * ***Taenia saginata* (beef tapeworm)** - more symptoms (digestive problems because they are larger in size) * ***T. solium* (pork tapeworm)** * ***T. asiatica* (Asian tapeworm)** * **humans are the only host** * portal of exit: segments in feces (contaminate soil) * cows and pigs infected after feeding - **migrate to striated muscle** (cysticercosis) * portal of entry: consuming raw or undercooked beef or pork * s/s: mild or nonexistent * **rare in U.S**. except where sanitation is poor

Question 30

**Western equine encephalitis** type of disease, where its found in the world, symptoms, mortality, prevalence

Answer 30

* encephalitis-causing arbovirus * endemic to western half of U.S. * rarely symptomatic * can cause severe neurological damage and death (4% mortality rate)

Question 31

Enterotoxigenic *E. coli* symptom, pathotypes, type of disease

Answer 31

* six pathotypes associated with diarrhea * most common cause of **traveler's diarrhea** * foodborne and waterborne bacterial disease

Question 32

viral envelopes which type is more stable in the environment?

Answer 32

* **non-enveloped:**"naked" have protein capsid surface * **more stable** in the environment * **enveloped:** plasma membrane containing host and viral protein, surrounds the virion as it exits the cell * enveloped purpose: **collect membrane** of host cell, not immediately recognized **(protection)**, more prone to break down in environment * **spikes:** surface viral proteins used in attachment

Question 33

diseases spread by **anopheles**

Answer 33

* malaria * elephantiasis

Question 34

Six types of microbes

Answer 34

1. bacteria 2. viruses 3. protozoa 4. fungi 5. algae (unicellular) 6. prions (subcellular; composed entirely of protein)

Question 35

pandemic

Answer 35

* classification of disease * epidemics that spread across continents * i.e. 1918 influenza, HIV/AIDS, malaria

Question 36

nonspecific immunity

Answer 36

* innate physiological defenses that operate to * block microbes from getting into body * eliminate microbes that have gotten into the body * present since birth * act against types of microbes, not specific microbes

Question 37

flu strains that emerged recently

Answer 37

* **bird flu H5N1** * 1997 Hong Kong * direct bird contact * high mortality rate * **swine flu of 2009 (H1N1)** * reassortment of pig, human, bird (antigenic shift) * reclassified as just another "seasonal" flu * 2015 huge outbreak in Iowa and Midwest in poultry and wild birds

Question 38

**shingles (herpes zoster)** type of disease, genome type, who does it affect, vaccine, transmission, host

Answer 38

* **varicella-zoster (DNA herpes virus)** * airborne viral disease * occurs after age 45 in some who had chickenpox as a child * **humans are the only host** * transmission: airborne and **contact with fluid** * **highly contagious** * vaccine - * **SHINGRIX** - zoster vaccine recombinant

Question 39

**transmissible spongiform encephalopathies (TSEs)** symptoms

Answer 39

* prion disease * s/s: loss of motor coordination, dementia, other neurological symptoms, death * **autopsy** reveals a **"sponge-like" brain full of holes** * no cure or treatment

Question 40

**plague** type of disease, causing agent, vector, reservoirs, epidemiology, types (mortality, s/s, transmission)

Answer 40

* arthropod vector disease * cause - ***Yersinia pestis*** * gram neg. bacillus * one of the most virulent bacteria known * killed 1/3 of Europe in 1300s * used as biological warfare * **reemerging infection** * **pacific plague focus** * ~50% acquired from visiting campgrounds or recreation sites * **southwest plague focus** * 80% acquired in peridomestic environments * sporadic cases due to prairie dogs * reservoirs - mammals, rodents * vector - flea * types of plague * **bubonic** * s/s - **buboes** (swollen lymph nodes) * can spread and cause **hemorrhages** * not normally infectious * **mortality \>50%** * **pneumonic** * bubonic plague then develop pneumonia * transmission - airborne * **100% fatal w/o early tx** * vaccine for high risk; not that effective * **septicemic** * spreads from lungs to rest of body * transmission - fecal-oral * **100% fatal**

Question 41

food intoxication (food poisoning)

Answer 41

* ingestion of bacterial toxins (with or without microbe being present) * symptoms appear quickly * n/v, diarrhea

Question 42

Nipah and Hendra virus

Answer 42

* Henipavirus * s/s: fever, headache, enchephalitis, coma * risk factor: close contact w/ pigs, consuming raw date palm sap, bats

Question 43

flat worms (digenian flukes) diseases

Answer 43

* schistosomiasis - bilharzia * opisthorchis sinensis - chinese liver fluke * paragonimus sp. - the lung fluke * echinostome (human fluke)

Question 44

antibody structure

Answer 44

Question 45

unicellular microbes

Answer 45

* protozoa * bacteria

Question 46

how can normal flora be opportunistic pathogens?

Answer 46

slippery see-saw between mutualism to parasitism; people with depressed immune systems are more prone to infections

Question 47

Thomas Malthus

Answer 47

* 1800s * preacher who warned that unchecked population growth would lead to faminine * the "hub" of the problem with population growth is increased tranmission of infectious agents

Question 48

direct transmission - horizontal transmission

Answer 48

* person-to-person * touch * sex * droplets * animal bites

Question 49

which type of viruses are resistant to hand sanitizer?

Answer 49

non-enveloped viruses

Question 50

humoral (antibody-mediated) immunity

Answer 50

* specific immunity * ​triggers **antibody production** specific for an antigen * antibodies are produced by **activated B lymphocytes with aid of TH cells​** * B lymphocytes are "activated" by contact with antigen and TH cells to become **antibody-producing plasma cells** * some B cells develop into **memory B cells** * all antibodies made by one B cell **bind to the same antigen**

Question 51

three main classes of parasites

Answer 51

* protozoa * helminths * ectoparasites

Question 52

**zika virus - flavivirus** type of disease, what its associated with, s/s, vaccination, at risk, dx

Answer 52

* arthropod viral disease * olympics outbreak in Brazil * **largely associated with travel** * can be sexually transmitted * s/s - usually none or mild * at risk - **pregnant women (microcephaly)** * use protection for 6 mos * association with Guillain-Barre syndrome (affects nerves) * dx - blood, urine, history * **no vaccine available** * **mosquito control is critical!**

Question 53

fungi that produces blue cheese

Answer 53

*Penicillium rouqueforti*

Question 54

what percentage of human disease are a result of viruses?

Answer 54

85%

Question 55

4 kinds of viral genomes

Answer 55

* dsDNA * dsRNA * ssDNA * ssRNA

Question 56

**Coccidioidomycosis** type of disease, s/s, dx, tx, incidence, where it is found, at risk

Answer 56

* **valley fever** * fungal disease * **endemic in AZ, CA, NV, NM, UT** * phoenix - 15-30% community acquired pneumonia * s/s - **flu-like** * at risk - travel to endemic states, adults \>60 yo, immunocompromised * dx - history, blood sample, sometimes chest x-ray and biopsy * tx - **usually none,** maybe antifungal meds

Question 57

**Hepatitis B virus** as an STD incubation, presentation, prevention, diagnostics, treatment, concentration in various body fluids

Answer 57

* incubation: 60-90 days * presentation: jaundice * dx: * HBsAg * Anti-HBc * IgM anti-HBc * Anti-HBs * prevention: * vaccination * hep B immunoglobulin * tx: * interferon * lamivudine

Question 58

**food poisoning**

Answer 58

* **food intoxication** * bacteria replicate in food or water and make toxins, which you ingest * examples: staph. food poisoning, *Bacillus cereus*, botulism, *C. perfringins* (70% fatal) * some self-resolving, others use antitoxin and supportive therapy

Question 59

bacterial STIs

Answer 59

* chlamydia * gonorrhea * syphilis

Question 60

**Rabies Virus** type of disease, virus type, vaccine, forms

Answer 60

* contact viral disease * formerly known as **hydrophobia** * caused by RNA virus * **vaccine for prevention and early tx** * **5 dose (day 0, 3, 7, 14, 28)** * **includes one dose of immunoglobullin** * two lethal forms: * **furious** (80%) - involves brain (aggression, foaming at mouth) * **dumb, or paralytic** - involves spinal cord (weak limbs, paralysis) * in the U.S. - bat bites

Question 61

**Botulism** microbe, source, therapy, disease type, s/s

Answer 61

* food intoxication (foodborne and waterborne bacterial disease) * *Clostridium botulinum* (g+ spore-forming bacillus) found in soil * source: improperly canned foods, low acid content foods * therapy: antitoxin and mechanical ventilation * s/s: muscle weakness, slurred speech, impaired vision * botox - removes wrinkles and reduces muscle overactivity

Question 62

nomenclature for Influenza A (subtypes)

Answer 62

H5N1 "Avian Flu" (2004 Vietnam) H1N1 "swine flu" of 2009

Question 63

viral replication **release**

Answer 63

* mechanisms: * **rupture (lyse)** the cell (i.e. phage and some animal viruses) * **budding** or "endocytosis in reverse" (some **enveloped** viruses) * gradual and doesn't kill the cell

Question 64

types of infectious disease transmission

Answer 64

* person-to-person * biological vector (mosquito to human) * zoonotic (animal to human; by consumption or biting)

Question 65

rotavirus genome type, what does it cause, vaccines

Answer 65

* **dsRNA** * most common cause of **severe/watery diarrhea in children** * oral vaccines (85-98% effective) **RotaTeq, Rotarix** * **cyclical** * **cause gastroenteritis** * foodborne and waterborne virus

Question 66

**deep mycoses** what does it lead to? who does it affect? how is it acquired?

Answer 66

* deep mycoses leads to systemic or disseminated infections and often spreads to the skin * usually in immunosuppressed * acquired by - * inhalation of fungi or spores * contaminated medical equipment

Question 67

**Leishmaniasis** type of disease, causing agent, where its found in the world, prevalence, presentations, transmission, reservoirs, dx, tx

Answer 67

* arthropod vector disease * cause - ***Leishmania*** **spp.** * **​**flagellated protozoan * **endemic in most tropical and subtropical areas worldwide** * transmission - bite of **female sand fly** * reservoirs - wild and domestic animals * presentation * **visceral leishmaniasis (kala-azar)** * **​~100% mortality if untreated** * invade liver and spleen * s/s - fever, weight loss, anemia, abd. protrusion * **mucocutaneous leishmaniasis (espundia)** * **​**invade skin and mucous membranes * **cutaneous leishmaniasis** * **​**mild to disfiguring skin lesions; ulcers * dx - **tissue** under light microscope * tx - **all visceral and mucosal presentations should be treated with pentavalent antimonial (Sb) therapy** * **significant side effects** - n/v, heaptotoxicity, cardiotoxicity (choose whether to treat cutaneous or not because side effects are significant)

Question 68

**Measles (rubeola)** type of disease, genome type, s/s, transmission, reservoir, where is it a problem, vaccine

Answer 68

* airborne viral disease * **ssRNA** * s/s: mild, cold-like * few are fatal due to complications (pneumonia, ear infections, seizures) * **Koplik's spots** in mouth followed by red rash on face then extremities * transmission: respiratory droplets * **highly infectious** * humans are the only reservoir * significant cause of death in developing countries * immunity is lifelong * **MMR vaccine**

Question 69

Drug resistant protozoan diseases

Answer 69

* malaria * visceral leishmaniasis

Question 70

**cryptosporidiosis** type of disease, microorganisms that causes it, where it occurs (example), transmission, dx, tx, life cycle, ID

Answer 70

* foodborne and waterborne protozoan disease * cause - ***Cryptosporidium parvum*** and ***C. hominis*** * **Milwaukee epidemic 1993** * **reservoirs - mammals, birds, reptiles** * **outbreaks worldwide, including UT** * complicated life cycle (asexual and sexual) * transmission - fecal-oral * typical s/s * dx - **several stool samples** (examined microscopically and PCR) * difficult; not routinely done * tx - **usually none** * fluids * anti-diarrheal medication * **chlorine resistant** * **ID 10 oocysts** * life cycle - **oocysts** undergo **excystation** to **sporozoites** that penetrate intestinal cells and multiply

Question 71

herd immunity (group immunity)

Answer 71

* the proportion of immunized individuals in a population * the smaller the number of susceptible individuals, the less opportunity for contact between them and infected individuals * herd immunity necessary depends on what infectious disease

Question 72

What are some issues with Koch's postulates?

Answer 72

* isolates only one microbe * ethical issues (polio only infects humans)

Question 73

what is a method used to improve compliance with TB antibiotics?

Answer 73

**Direct Observational Therapy Short Course (DOTS)** deliver antibiotics daily and ensure compliance

Question 74

**Rubella (german measles)** type of disease, genome type, s/s, transmission, RISK FACTOR, where is it found, vaccine

Answer 74

* airborne viral disease * **ssRNA** * **highly infectious;** mildest rash-forming virus * **endemic worldwide** * **eradicated from U.S.** in 2004 * s/s: low fever, rash (2-3 days), cold-like * 50% asymptomatic * transmission: airborne and urine * risk factor: **prenatal transmission** * **85% of babies born to mothers who has rubella in the first 3 mo of pregnancy have defect** * MMR vaccine

Question 75

Question 76

virulence

Answer 76

* refers to the severity of the disease * measured by the proportion of total cases with overt infection divided by the total number of infected cases * if fatal, use case fatality rate

Question 77

Hib infections include...

Answer 77

* meningitis * bacteremia * pneumonia

Question 78

drug resistance in TB

Answer 78

* **multiple drug-resistant (MDR)** * resistant to INH and RIF * **extremely drug-resistant (XDR)** * ​reisistant to multiple treatments; rare but increasing

Question 79

Exotoxins

Answer 79

* offensive strategy * proteins synthesized by the microbe and secreted into the host's tissues * examples: * cytotoxins - kill or damage cells * neurotoxins - block nerve impulse transmission * enterotoxins - affect cells lining GI tract

Question 80

**Enterobiasis** type of disease, cause, where its found, transmission, s/s, tx, dx

Answer 80

* **"pinworm disease"** * roundworm disease * caused by *Enterobius vermicularis* * **most common helminthic disease in the U.S.** * transmission: direct contact, bedclothes, inhalation * s/s: anal itch * **drug treatment** is effective * dx. **scotch tape test**

Question 81

**Giardiasis** type of disease, microorganism that causes it, how common is it, s/s, dx, tx, life cycle, portal of entry and exit, ID

Answer 81

* foodborne and waterborne protozoan disease * cause - ***Giardia lamblia*** or ***G. duodenalis*** * flagellated protozoan * **one of the most common waterborne diseases in the U.S.** * transmission - * swallow cysts in contaminated water * **fecal-oral route** (day care, veggies) * **ID ~10 cysts** * shed 1-10 billion cysts daily in feces * **chlorine resistant** * life cycle - * cysts enter body by oral route -\> sexually reproduce into trophozoites -\> **trophozoites attach to intestinal lining by sucking disks** -\> defecated out (don't survive long in environment) * s/s - **fatty stool** (steatorrhea) * begin 1-3 wks after infection * self limiting ~10 days * tx - **drug treatments** (i.e. metronidazole) * dx - **3 stool samples** (phases of shedding)

Question 82

**cryptococcosis** type of disease, where it is found, pathogens, s/s, tx, dx, at risk

Answer 82

* reportable in **Oregon and Washington** * fungal disease * s/s - flu-like * can disseminate to other organs * inflammation of brain and meninges * pathogens - * ***Cryptococcus neoformans*** * found in soil * transmit by inhalation * causes **cryptococcal meningitis** (sub-saharan africa) * laten infection or symptomatic disease * ***C. gattii*** * ​symptoms 2-14 mos after exposure * at risk - immunocompromised * dx - microscope, culture (cannot distinguish between two species) * tx - **antifungal for at least 6 mos**

Question 83

sterilization

Answer 83

kills everything (usually \>6 logs), including spores

Question 84

how are viruses selected each year for the influenza vaccine?

Answer 84

* send viruses to 5 reference labs: * Atlanta, Georgia * London * Melbourne, Australia * Tokyo, Japan * Beijing, China

Question 85

foodborne infection

Answer 85

* bacteria multiply in the intestinal tract and secrete **enterotoxin** * cause n/v, diarrhea, possible bloody stools * symptoms as early as one hour after eating to as late as 10 days * can last from one day to months

Question 86

Answer 86

kissing bug that spreads chaga's disease

Question 87

Answer 87

sand fly that transmits Leishmaniasis

Question 88

Drug resistant bacterial diseases

Answer 88

* tuberculosis * gonorrhea * staphylococcal infection * shigellosis * typhoid fever * pneumococcal pneumonia * enterococcal infection * acinetobacter infection

Question 89

John Snow

Answer 89

* 1849 * cholera outbreak in Broad Street, London * linked to contaminated water supplies * removed handle from pump -\> decrease in cholera

Question 90

**schistosomiasis (bilharzia)** type of disease, what causes it, s/s, place it occurs, portal of entry and exit, dx, tx

Answer 90

* **flat worm (fluke) infection - most important** * malaria is the only **nastier parasitic infection** * caused by **blood flukes** * *Schistosoma japonicum* * *S. haematobium* * *S. mansoni* (associated with hepatosplenic disease) * many countries, but **not present in the U.S.** * requires **freshwater snail host** * portal of entry: **penetrate the skin of bathers and migrate into the blood vessels** * adult worms escape detection by coating themselves with host antigens * can infect primary organs * can have infection for years * worms feed on blood (heart and liver) * **portal of exit: feces and urine** * s/s: itchy, flu-like * major - damage to liver, intestine, bladder (distended abdomen) * rare - move to brain or spinal cord * **dx. find eggs in urine or stool (multiple days)** * serum testing for antibodies (6-8 wk post infection) * **tx. available**

Question 91

Drug resistant viral diseases

Answer 91

* HIV * hep B * hep C

Question 92

4 classifications of fungal diseases

Answer 92

* superficial mycoses * subcutaneous mycoses * mucocutaneous mycoses * deep mycoses

Question 93

antibiotic therapy for TB and what is an issue?

Answer 93

* **primary infection: isoniazid - 6 mos** * **primary active TB disease: antibiotic combination for 6-9 mos** * combinations include **isoniazid (INH), rifampin (RIF),** streptomycin, ethambutol, pyrazinamide daily 2 mos; then INH + RIF daily 4 mos * possible toxicity * compliance, affordability, and access are an issues

Question 94

what type of virus is this?

Answer 94

ebola

Question 95

diagnosis of TB

Answer 95

* **Tuberculin skin test (Tst)** * **purified protein derivative (PPD)** is injected * examine site after 48-72 hrs * lesion **\>5 mm** is positive (just means previous exposure) * **chest x-ray** * **sputum test**

Question 96

smallpox history

Answer 96

* described **10,000 years ago** * pox scars on **mummy of Pharaoh** Ramses V from 1157 B.C. * **biowarfare** - british troops gave contaminated blankets to native americans * **edward jenner** developed the **vaccine** in 1796 - "first vaccine" * only disease agent to be **eradicated**

Question 97

measures taken to reduce numbers of new HIV diagnosis

Answer 97

* **alert physicians** by sending letters * **PrEP** recommendation for HIV-negative, high risk contacts * increased **prevention, testing,** and **education** efforts * **decrease stigma** around homosexuality

Question 98

reproduction rate (R₀)

Answer 98

* measure of the potential for transmission * mean number of secondary cases, occurring in a nonimmunized population in the wake of a particular infection * factors to consider: population density, duration of contagiousness * R₀ must be \>1 to spread; \<1 will die out * directly linked to herd immunity * can have high R₀ and low virulence, vice versa

Question 99

why are there so many new flu strains?

Answer 99

* RNA virus so **no proof-reading** in replication -\> random **replication errors** * 10⁹ in host, so 1/1,000,000,000 means every host has 1 mutant * 8 segments -\> **reassortment**

Question 100

**fish tapeworm** portal of entry and exit, where its found, what it leads to

Answer 100

* *Diphyllobothrium latum* - **largest parasite that infects humans** (30 ft) * portal of entry: eating raw and undercooked **freshwater fish** that contain fish tapeworm cysts * rivers or lakes **worldwide** * portal of exit: stool * may lead to vitamin B12 deficiency and anemia

Question 101

**viruses** unicellular, multicellular, or acellular? submicroscopic or microscopic? genome? examples?

Answer 101

* acellular * genome RNA or DNA * obligate intracellular parasite * submicroscopic * examples: HIV/AIDS, measles, rabies

Question 102

**biology of fungi** eucaryotic or prokaryotic? unicellular or multicellular? forms? life cycle? how many species? how many cause disease?

Answer 102

* **eucaryotic** * **unicellular (yeasts) or multicellular (molds)** * **microscopic (yeasts)** * complex life cycles (asexual/sexual) * mode of multiplication - **spore formation** * inhaled or land on skin * over **50,000 species** of fungi * only about **25 cause disease**

Question 103

disinfection

Answer 103

kills all _but_ spores (usually 5 logs)

Question 104

**Salmonellosis** cause, treatment, carriers of salmonella, type of disease

Answer 104

* *Salmonella* (g- bacilli) * tx. antibiotics not necessary unless spreads from intestines * carriers: iguanas, lizards, snakes, turtles * symptom: *Salmonella* enteritidis * foodborne and waterborne bacterial disease

Question 105

**Algae** unicellular, multicellular, or acellular? prokaryotic or eukaryotic? submicroscopic or microscopic? genome? replication? metabolism? cell wall or no cell wall?

Answer 105

* unicellular or multicellular * eucaryotic * microscopic (unicellular only) * DNA genome * asexual replication * cell wall * metabolism - photoautotrophs * not infectious; some produce neurotoxin

Question 106

foodborne and waterborne bacterial diseases (3 food intoxications and 7 food poisoning)

Answer 106

Question 107

portal of entry and portal of exit

Answer 107

* **portal of entry** important for outcome of infection * **portal of exit** required for transmission to a new host

Question 108

**Hepatitis A** type of genome, s/s, transmission, dx, vaccination

Answer 108

* **+ssRNA** * s/s: **mild,** abrupt onset * jaundice, n/v, dark urine * many asymptomatic * transmission: fecal-oral * dx: detect antibodies in blood * vaccine available * **2 dose series 12-23 mos** * foodborne and waterborne virus

Question 109

chronic carrier

Answer 109

harbor pathogen for long periods of time after recovery, without ever becoming ill again do not transmit

Question 110

**Ascaris Lumbricoides** type of disease, where it occurs, portal of entry and exit, tx, s/s, how common is it

Answer 110

* roundworm disease * **most common human worm infection** * infects ~25% of world's population * **tropics and subtropics** * 50% of children infected in **southeast U.S.** * infects small intestine * many asymptomatic * mild abdominal discomfort * damage to lungs may occur * severe cases - malnutrition, suffocation, **intestinal obstruction**, impaired growth, invade gallbladder and liver, death * portal of exit: feces * portal of entry: ingestion (hands or food contaminated with dirt containing feces) * tx. chemo medication

Question 111

biological indicators

Answer 111

* *Bacillus sterothermophilus* heat-resistant * *Bacillus subtilis* chemical resistant

Question 112

**Tularemia (rabbit fever)** type of disease, cause, virulence, transmission, s/s, can be used as, tx, vaccine

Answer 112

* airborne bacterial disease * zoonotic disease * ***Francisella tularensis*** (g- bacillus) * **highly virulent** and low ID * Reservoirs: small animals * transmission: * inhalation * contact w/ infected animals * ingestion of contaminated food or water * **tick bites** (most common) * s/s - depends on how it enters the body (ulceroglandular/glandular, oculoglandular, oropharyngeal, pneumonic) * **high fever 104ºF** * potential **biological weapon** * tx: antibiotics for 10-21 days * vaccine for high-risk

Question 113

antiviral mechanisms (5)

Answer 113

* **Neuraminidase inhibitor** * tamiflu (zanamivir). BTA938 is better * attach to receptors on virion so new virions can't be released * **attachment inhibitor** * anitbodies * **RNA-dependent RNA polymerase inhibitor** * ribavirin * **protease inhibitor** * in HAART for HIV * **reverse transcriptase inhibitor** (HIV) * originally AZT

Question 114

**Pertussis - Whooping cough** type of disease, causing agent, reservoir, damage, prevalence, where its found in the world, tx, prevention

Answer 114

* airborne bacterial disase (upper respiratory) * ***Bordetella pertussis*** (g- coccobacillus) * **humans are only reservoir** * very contagious! * **exotoxin** damages ciliated cells in airway * **reemerging disease** * **endemic in U.S.** * ​epidemic q3-5 yrs * tx: antibiotics (but cough will persist) * prevention: **vaccination** (DTaP) * booster every 10 years

Question 115

capsules as defensive stategy and examples

Answer 115

* removal of the capsule makes bacteria more susceptible to phagocytosis * examples: Anthrax, plague, streptococcal diseases (i.e. scarlet fever, "strep" throat, pneumococcal infection)

Question 116

symbiosis

Answer 116

"living together" an association between two or more species (i.e. mutualism, parasitism, commensalism)

Question 117

toxigenicity

Answer 117

* the capacity of the agent to produce a toxin or poison (i.e. *Clostridium botulinum*) * = # affected / # exposed

Question 118

2015 HIV outbreak what intervention was used?

Answer 118

* **Scott County, Indiana** * **socio-economic factors** (unemployment, uneducated, poverty) * up to **3 generations injecting together** (oxymorphone) * ~93% **hep C coinfection** * 181 outbreak-related HIV infections identified in about one year * intervention: * **contact tracing**

Question 119

what is the singular purpose of a virus?

Answer 119

replicate themselves as many times as possible and destroy cells in its pathway

Question 120

what type of virus is this?

Answer 120

rotavirus

Question 121

In Utah, HIV is commonly coinfected with what disease?

Answer 121

primary and secondary syphillus infections

Question 122

**malaria** type of disease, causing agent, mortality, s/s, transmission, tx, dx, prevention, where is this disease found in the world

Answer 122

* arthropod vector disease * s/s - **multiple episodes of flu-like symptoms** * 85% of deaths in **children** * cerebral malaria 1-2% mortality rate * ancient disease * cause - ***Plasmodium* spp.** * non-motile protozoan * four major species: ***P. falciparum, P. vivax****, P. malariae, P. ovale* * *​P. falciparum* causes **cerebral malaria** * transmission - **anopheles mosquito** (primary host) * humans are secondary host * tx. anti-malarial drugs - **chloroquine** * infect **RBCs** * significant in **sub-saharan africa** * dx. blood smear * prevention * spraying * mosquito nets

Question 123

passive immunization

Answer 123

* preformed antibodies - **immune serum or immunoglobulin** * antibodies (antitoxin or anti-venom) **present immediately** * **short-lived, no memory** * **serum sickness** due to immune reaction

Question 124

roundworms (nematodes)

Answer 124

* enterobius vermicularis (pinworms) * ascaris lumbricoides * trichinellosis * trichuris trichuria * hookworms * lymphatic filariasis - elephatiasis * onchocera volvulus - river blindness * dracanculus medinensis - guinea worm

Question 125

**Aspergillosis** type of disease, where is it found, at risk, s/s, dx, tx, incidence, mortality rate

Answer 125

* fungal disease * found - indoors and outdoors * at risk - immunocompromised (ashma, transplants, cystic fibrosis, chemo, HIV) * **rare;** not reportable * **mortality 100%** (death in weeks) * s/s - * **allergic bronchopulmonary signs** (wheezing, coughing) * **invasive aspergillosis symptoms** (fever, shortness of breath, aspergilloma) * dx - chest x-ray, CT, biopsies * tx - antifungal meds (Amphotericin B and itraconazole) * **usually ineffective**

Question 126

active carrier vs healthy carrier (reservoirs of infection)

Answer 126

* **active carriers** - individuals who have a microbial disease * **healthy carriers** - have no symptoms but still transmit * typhoid mary (mary mallon) * continue to harbor the microbe after recovery

Question 127

**Naegleria fowleri** where is this disease found, fatality, transmission, s/s, dx, tx, prevalence

Answer 127

* **primary amebic meningoencephalitis** * **brain-eating amoeba!** * affects nasal passages * typical in southeast * **warm or hot freshwater around the world** * **rare** * transmission - **contact with contaminated water but NOT INGESTION** * chlorine resistant * **death within 10-12 days** * **​almost 100% fatal** * s/s - * stage 1 - headache, nausea * stage 2 - stiff neck, seizures, hallucinations (**looks like meningitis)** * dx - organism in **CSF**, PCR * **investigational drug - CDC miltefosine**

Question 128

active immunization

Answer 128

* stimulates immune system to produce antibodies and memory cells * **natural active immunity** * **artificial active immunity**

Question 129

**Enterovirus EV-D68** s/s, how common is it

Answer 129

* uncommon * related to rhinovirus and poliovirus * s/s: respiratory (worse than a cold)

Question 130

six factors responsible for emerging infections

Answer 130

* world population growth * urbanization * ecological disturbances * technological advances * microbial evolution and adaptation * human behavior and attitudes

Question 131

**Encephalitis-causing arboviruses** types, where they are found, type of virus, surveillance, reservoirs and dead-end hosts

Answer 131

* west nile fever, eastern equine encephalitis, western equine encephalitis, St. Louis encephalitis, colorado tick fever * U.S. * all are RNA viruses * viruses cycle between wild animals (primarily birds and mosquitos) with humans and horses serving as dead-end hosts * surveillance - * test adult mosquitos * draw blood from chicken populations

Question 132

how many hospitalized patients will contract a hospital-acquired infection?

Answer 132

1 out of 20

Question 133

DTaP \<7 years

Answer 133

5 dose series 2 mos 4 mos 6 mos 15-18 mos 4-6 yrs

Question 134

lymph

Answer 134

fluid derived from blood and drains back into blood

Question 135

waxy coat

Answer 135

* defensive virulence strategy * interferes with phagocytosis * example: *Mycobacterium tuberculosis*

Question 136

clonal selection theory

Answer 136

explains how antigens select the appropriate B cells for activation and clonal expansion as plasma cells

Question 137

**Staphylococci** type of disease, type of bacteria, where it normally resides, what does it cause

Answer 137

* bacterial contact disease * **g+ cocci** * normal flora * harmless unless skin barrier is broken down * causes: * purulent (pus containing) skin lesions, pimples, boils, carbuncles * can progress to systemic infections

Question 138

Cholera intoxication cause, how common is it, characteristic, tx, type of disease

Answer 138

* caused by **exotoxin** secreted by ***Vibrio cholerae*** (g- curved rod) * **pandemics** over the centuries * rare in U.S. * characteristic: **rice water diarrhea** * **oral rehydration therapy can save lives** * foodborne and waterborne bacterial disease

Question 139

Ignaz Semmelweis

Answer 139

* mid 1800s * "savior of mothers" * antiseptic procedures * suggested that childbed fever resulted from physicians not washing their hands after dissections * could not "prove" and was disregarded

Question 140

Answer 140

*Salmonella* (g- bacilli) causes Salmonellosis bacterial foodborne and waterborne infection

Question 141

**lyme disease** type of disease, causing agent, s/s, tx, dx, where its found in the world, prevalence, life cycle

Answer 141

* arthropod vector disease * cause - ***Borrelia burgdorferi*** * ***​***gram neg. spirochete * **tickborne zoonosis** * worldwide * worst vectorborne disease in U.S. (morbidity) * high incidence in **Maine** * first found in Old Lyme, Connecticut * s/s - flu-like, long-lasting, **"bull's-eye" skin rash,** arthritis * dx - history, blood tests * tx - early tx with **antibiotics** leads to quick recovery * **vaccine under development** * **complex 2 year life cycle**

Question 142

**Herpes simplex virus** cause, presentation, incubation, dx, tx, race/ethnicity rates

Answer 142

* caused by ***herpes simplex virus type 2 and type 1*** * **leading cause of genital ulcer disease worldwide** * incubation: **~4 days** * presentation: * genital ulcurs, pain, itching, dysuria, discharge * dx: type-specific IgG-based assay * tx: **antivirals (acyclovir, valacyclovir, or famciclovir)** * rates: * **non-hispanic blacks** the most infected

Question 143

Gastroenteritis type of disease, symptoms, causes

Answer 143

* s/s: stomach and abd pain/camps, diarrhea, vomiting * caused by viruses: rotavirus, norovirus, adenovirus * foodborne and waterborne viral disease

Question 144

What types of **human behaviors and attitudes** have contributed to emerging infections?

Answer 144

* **complacency** - false assumption that prevention and control are no longer necessary * examples: threatened resurgence of AIDS, lack of compliance with immunizations * **human migration** * **internally displaced persons** lack water, shelter, food, and hygiene = increased infection * **refugees** transmit infection from native lands * **societal factors** * ​day care * increased elderly population * globalization of food supply * tattooing and body piercings

Question 145

**acute schistosomiasis** another name, type of disease, s/s

Answer 145

* **'Katayama' fever** * flat worm (fluke) disease * s/s: resembles **'serum sickness'** * often asymptomatic * flu-like; extreme cases - diarrhea (last weeks to months)

Question 146

Measles, mumps, and rubella are caused by a specific virus in the family.

Answer 146

**paramyxoviridae**

Question 147

**toxoplasmosis** type of disease, reservoir and host, microorganism that causes it, where its found in the world, prevalence, s/s, tx, at risk, transmission, life cycle

Answer 147

* foodborne and waterborne protozoan disease * cause - ***Toxoplasma gondii*** * non-motile protozoan * **worldwide zoonosis** * **domestic and wild cats are primary reservoir and host** * **rare** * transmission - **ingestion of oocysts in cat feces or eating undercooked meats** * s/s - * **usually asymptomatic or mild** (sore throat, fever, swollen lymph nodes) * **at risk - pregnant women, immunocompromised** (invasion of the brain) * tx - **drugs for up to 1 yr**

Question 148

pre-exposure prophylaxis

Answer 148

HIV prevention strategy

Question 149

**Bacterial Meningitis** type of disease, dx, s/s, two common causes (tx, at risk, vaccine, carriers)

Answer 149

* airborne bacterial disease * inflammation of meninges * **diagnose early** * s/s: cold-like, possible delirium, stiffness in neck and back * 10-15% death rate w/ tx * 11-19% long-term disabilities * two most common causes: * ***Neisseria meningitidis*** (g- diplococcus) * 10% carriers * person-to-person respiratory transmission * tx: **meningococcemia**, antibiotic therapy * at risk: college students (**prophylaxis antibiotics**) * **vaccine recommended for ages 10-25** * protects against **three serotypes (B, C, Y)** * ***Haemophilus influenzae*** **type b (Hib)** (g- bacillus) * at risk: children \<5 * vaccine has decreased incidence * 10% healthy people carry Hib in nose and throat

Question 150

viral genome replication for dsDNA

Answer 150

Question 151

influenza surface antigenic protein spikes

Answer 151

* **H (hemagglutinin)** spikes * 18 subtypes (H1 - H18) * **N (neuraminidase)** spikes * 9 subtypes (N1 - N9) * specific antibodies against the H and N proteins are protective, but these proteins are capable of **rapid evolutionary change**

Question 152

**colorado tick fever** type of disease, where its prevalent

Answer 152

* encephalitis-causing arboviruses * transmission - ticks * prevalent in mountain forest environments at high altitudes

Question 153

**primary and secondary syphilis**

Answer 153

* caused by bacterium ***Treponema pallidum*** * incubation: **~3 weeks** * presentation: * chancres (sores) * rash * dx: site specific * urine * swabs * tx: **Benzathine penicillin G 2.4 million units IM** * no sex for 1 week * rates: * U.S. higher than UT * increasing * males more infected than females * age 20-24 * MSM cases increasing * **coinfects with HIV** (decreasing)

Question 154

*E. Coli* O157:H7 syndrome is causes, type of disease

Answer 154

* foodborne and waterborne bacterial disease * **Hemolytic uremic syndrome** may result in death in children \<5

Question 155

Hep B vaccine

Answer 155

3 doses birth 1-2 mos 6-18 mos

Question 156

diseases spread by **culex**

Answer 156

* west nile * elephantiasis * st. louis encephalitis * eastern equine encephalitis

Question 157

**west nile fever** type of disease, where its found in the world, prevalence, symptoms, affected

Answer 157

* encephalitis-causing arboviruses * emerging disease in the U.S. * mammals are susceptible * usually no sympoms * if symptoms are present, it's usually severe (paralysis)

Question 158

**triazoles**

Answer 158

* antifungal drug * ergosterol biosynthesis inhibitor * fluconazole, itraconazole

Question 159

What percentage of the human population lives in less developed countries?

Answer 159

80%

Question 160

Retroviruses

Answer 160

* use **reverse transcriptase** (make DNA from RNA) * examples: HIV, SIV, HTLV-1

Question 161

*Salmonella typhi* s/s, tx, prevention

Answer 161

* organism invades cells lining small intestines, causing ulcers, bloody stools, fever, possible delirium * tx: antibiotics, wash hands * prevention: two vaccines available - neither 100% effective and requires repeated immunization

Question 162

**Rocky mountain spotted fever** type of disease, causing agent, transmission, s/s, tx, dx

Answer 162

* arthropod vector disease * cause - ***Rickettsia rickettsii*** * transmission - **tick bite** * s/s - flu-like, **distinct rash** * **fatal in first 8 days if untreated** * hard to dx * **diagnostic tests can appear negative in first 10 days** * tx - antibiotic (doxycycline)

Question 163

transmission and infectivity of TB

Answer 163

* transmitted by **droplets** * bacilli have **waxy outer coats** that protect from drying out * **moderately infectious** * 20-30% of people exposed to **active case** will become infected * may have to have **repeated exposures**

Question 164

importance of pH in food safety

Answer 164

* acidic pH \<4.0 will only grow fungi but not bacteria * bacterial spores do not germinate in acidic environments

Question 165

why do we catch a cold or flu when it's cold outside?

Answer 165

* **dry membranes** (15% relative humidity) * forced inside (less fresh air and more crowded) * down-regulated immune system (less exercise and less positive)

Question 166

post exposure prophylaxis

Answer 166

HIV prevention strategy 80% effective

Question 167

**Hepatitis E** genome type, transmission, countries is it found, vaccine, presentation

Answer 167

* **ssRNA** * transmission: fecal-oral * **uncommon in U.S.** * **endemic** in Africa, India, Asia, Central America * **No vaccine** * ​recently recommended but **low risk?** * foodborne and waterborne virus * presentation similar to Hep A

Question 168

foodborne and waterborne protozoan diseases (4)

Answer 168

* giardiasis * amebiasis * sporozoa * toxoplasmosis

Question 169

monkeypox

Answer 169

* milder symptoms than small pox * fatal in Africa * transmission: animal bites, contact with animal blood, fluids, rash, person-to-person (droplets and face-to-face contact)

Question 170

Endotoxin

Answer 170

* offensive strategy * part of the lipopolysaccharide in the outer membrane of gram negative cells * it causes shock, chills, fever, weakness, small blood clots, possibly death

Question 171

disinfection methods

Answer 171

* **chemical disinfection** * lysol phenolic * **desiccation (drying)** * kills most enveloped viruses and vegetative bacteria * microbial safety of dry desert climates like UT * **alcohol** * kills enveloped viruses immediated * non-enveloped viruses - no or very long contact time * vegetative bacteria - 30-120 seconds contact * spore-forming bacteria - never * **boiling** * 10 minutes destroys exotoxins * kills fungi and vegetative bacteria * does not kill spores

Question 172

Infectious diseases are the leading cause of death worldwide

Answer 172

second

Question 173

**epidemiology**

Answer 173

an investigative branch of medicine that deals with the source, cause, and possible control of infectious disease and other public health problems

Question 174

endemic

Answer 174

* classification of disease * regularly found at a steady level in a particular location * i.e. common cold

Question 175

more virulent = low and high

Answer 175

more virulent = low ID and high LD ID and VD are usually inversely correlated

Question 176

Botulinum toxin vs tetanus toxin

Answer 176

* Botulinum toxin causes flaccid muscle paralysis * Tetanus toxin causes stiffness * Exotoxins

Question 177

two types of epidemic

Answer 177

* **common source** - involves contact with a single contamination source * **propagated** - results from person-to-person contact (i.e. mumps, chicken pox) * pandemics are typically propagated

Question 178

**Chickenpox (varicella)** type of disease, genome type, s/s, tx, vaccine, transmission, where it occurs, host

Answer 178

* ariborne viral disease * **varicella zoster (dsDNA herpes virus)** * s/s: high fever, tired, headache * **rash that turns blisters to scabs** * transmission: airborne * tx: **acetaminophen (non-aspirin)** * aspirin and chickenpox associated with **Reye's syndrome** * usually occurs in children * **still prevalent worldwide** * can cross placenta * vaccine: * **zostovax** (live, attenuated) - 1994; requires booster * 2010 - **MMRV** available * **humans are the only host**

Question 179

how are commercial foods preserved? (6)

Answer 179

* desiccation * osmotic pressure * fermentation * heat * pasteurization * 10⁵ bacteria/mL after, but no coliforms * old way - 60ºC for 30 min * high temp short time - 72ºC for 15 sec * ultra high temp - 140ºC for 4 sec (flavor change) * irradiation sterilization

Question 180

Tdap (\> 7 yrs) vaccine

Answer 180

11-12 yrs in adulthood, 1 dose Tdap, then Td booster every 10 years

Question 181

***Clostridium perfringens*** type of disease, source

Answer 181

* food intoxication (foodborne and waterborne bacterial disease) * source: meat, poultry, beans

Question 182

cell culture antiviral assays (FYI)

Answer 182

Question 183

**Prions** unicellular, multicellular, or acellular? submicroscopic or microscopic? genome? replication? examples?

Answer 183

* acellular * infectious protein particles * no genome * submicroscopic * reproduce by physically interacting with a normal protein and converting it to the infectious form * diseases: mad cow disease, scrapies

Question 184

penetration in viral replication

Answer 184

* strategies of delivering genome to cytoplasm: * **nucleic acid alone** enters the cell (i.e. phage, polio) * for some enveloped viruses (i.e. measles, mumps) the **viral and cell membranes fuse** to release nucleocapsid * for other enveloped viruses (i.e. poxviruses, influenza) the entire virion is **endocytosed**

Question 185

MERS = middle eastern respiratory syndrome

Answer 185

* like SARS * current * 35% mortality rate * found in 27 countries * likely zoonotic (from camels)

Question 186

virus classification based on nucleic acid composition (5 dsDNA, 7 ssRNA, 2 dsRNA)

Answer 186

Question 187

prokaryote vs eukaryote

Answer 187

* **prokaryote** - no internal compartments; no nucleus * **eukaryote** - membrane-bound compartments

Question 188

what do anti-HIV therapies target?

Answer 188

* HIV adsorption * entry of reverse transcriptase * assembly of new virions

Question 189

Answer 189

*Campylobacter jejuni* (g- bacillus, curved) causes Campylobacteriosis bacterial foodborne and waterborne disease

Question 190

**chronic hepatosplenic schistosomiasis**

Answer 190

* flat worm (fluke) disease * seen a few years after infection * **granulomas** around eggs trapped in **liver** =\> **fibrosis**

Question 191

**Hantavirus pulmonary syndrome** type of disease, genome type, first reported, s/s, transmission, dx, strain and fatality rate, who does it affect

Answer 191

* airborne viral disease * **ssRNA** * known as hemorrhagic viruses in Africa * first reported in four corner areas of the U.S. * s/s: **early symptoms are severe flu-like** * **late symptoms: lungs fill with fluid** * **Sin Nombre strain** attacks lungs - 38% fatality rate (death within days) * affects **young, healthy adults** * carried by **rodents** * transmission: aerosolized feces, salive, urine of rodents; not person-to-person * **dx: difficult** (looks like flu) * hantavirus specific IgM, RNA by RT-PCR

Question 192

drug resistant fungal diseases

Answer 192

* aspergillosis * candidiasis * cryptococcosis

Question 193

airborne bacterial diseases

Answer 193

Question 194

nucleocapsid

Answer 194

viral proteins + genome

Question 195

**yellow fever** type of disease, where its found in the world, vector, reservoir, s/s, tx, vaccination, mortality rate

Answer 195

* arthropod viral disease * RNA virus * cause - ***Aedes aegypti*** * **New Orleans** was last site of U.S. epidemic * **south and central america, africa** * reservoirs - **monkeys** * s/s - flu-like, **jaundice** * within a week infected person is either dead or recovering (20-20% mortality rate) * **immunization available for travelers (very effective)** * **nearly 100% fatal (no good treatments)**

Question 196

what are antigens?

Answer 196

large foreign-proteins associated with microbes, tumor cells, pollen, dust, food, etc.

Question 197

MMR vaccine

Answer 197

2 dose series 12-15 mos 4-6 yrs 1 or 2 doses (19-60 yrs)

Question 198

**biology of protozoans** eucaryotic or prokaryotic? how many species? distribution? life cycle?

Answer 198

* **eucaryotic** * **worldwide ~20,000 species** * few are pathogenic * complicated life cycle; more than one host * **encystation** forms a **dormant cyst** * **excystation** to the **trophozoite** form occurs after ingestion and is in the **reproductive and feeding stage**

Question 199

**polio virus** genome type, s/s, transmission, vaccine, dx, risk factors

Answer 199

* **+ssRNA** * s/s: ~70% asymptomatic * minor symptoms (flu-like) * \<1% paralysis (some die from paralysis of respiratory muscles) * transmission: person-to-person (fecal-oral) * **only affects humans** * dx: stool sample or throat test * vaccine: **salk vaccine** (killed virus) -\> **sabin vaccine** (live, attenuated) * 4 dose vaccine schedule - 2 mo, 4 mo, 6-18 mo, booster 4-6 yrs * risk factors: travel, working in lab or healthcare * causes disease poliomyletis * foodborne and waterborne viral disease * **close to eradication**

Question 200

5 stages of viral replication cycle

Answer 200

Question 201

first exposure of TB

Answer 201

* first exposure of TB results in a **primary infection** (usually **asymptomatic**) * usually in the **lungs**, but can also occur in the skin, brain, spinal cord, kidney, and bone * immune cells usually fight off the bacilli in the **granulomas** 90% of the time

Question 202

Listeriosis type of disease, cause, distribution, source, s/s, tx, at risk

Answer 202

* foodborne and waterborne bacterial disease * ***Listeria monocytogenes*** (g+ bacillus) * distributed worldwide * souce: cold cuts, hot dogs, soft cheeses - **grows under refrigeration** * s/s: fever, muscle aches, stiff neck - **blood and spinal fluid have bacteria** * tx: antibiotics * at risk: **pregnant women,** infants, elderly, immunocompromised

Question 203

virulence mechanisms of eucaryotic microbes (including helminths)

Answer 203

combination of offensive and defensive strategies described for bacteria (adhesins, toxins, antigenic variation, etc.)

Question 204

**white nose syndrome** type of disease, pathogen, what does it cause, what species does it affect

Answer 204

* environmental fungi disease * pathogen - ***Pseudogymnoascus destructans*** * affects **bats** * causes fungal growth on muzzle and wings, skin erosion, and abnormal behavior

Question 205

**American trypanosomiasis (chaga's disease)** type of disease, causing agent, where it occurs in the world, prevalence, s/s, transmission, vector, reservoir, prevention

Answer 205

* arthropod vector disease * cause - ***Trypanosoma cruzi*** * flagellated protozoan * occurs in **central and south america** * millions infected * reservoirs - wild animals * vector - **"kissing bug" (triatomid)** * live in roofs and huts, feed at night * **defecates as it bites**, then trypanosomes spread into skin from scratching * transmission also by blood transfusion and organ transplant * s/s * more mild than african trypanosomiasis * 1-2% swollen eyelids **(Romaña's sign)** * slow, widespread tissue damage; **heart failure** within 30 yrs if untreated * prevention * spraying * replacing roofs with metal

Question 206

**amebiasis** type of disease, microorganism that causes it, where in the world its found and what environment, prevalence, fatality rate, s/s, tx, dx, life cycle

Answer 206

* foodborne and waterborne protozoan disease * causes - ***Entamoeba histolytica*** * **worldwide** * **chlorine resistant** * **one of the most common parasitic disease** * **​10% fatality** * found in **water** * s/s - * **90% asymptomatic or mild** * **severe dysentery** * deep **ulcers** and invade other parts of body; **hepatitis** * tx - **several drugs** * dx - **trophozoites or cysts** in **fecal smears** * life cycle - * 2 pathways: * **invasive infection** - enters blood and infects liver, brain, lungs * **noninvasive infection** - cysts exits host in stool

Question 207

**chronic intestinal schistosomiasis** type of disease, s/s

Answer 207

* flat worm (fluke) disease * manifests years after infection * s/s: **fibrosis,** lesions on small and large intestines * granulomas

Question 208

What kind of infectious diseases can come about from **organ transplants** or **invasive medical procedures** (i.e. biopsy)?

Answer 208

* HIV * chagas' disease

Question 209

**Leptospirosis - swamp fever** type of disease, pathogen, where it is most common, transmission, symptoms, tx

Answer 209

* soilborne bacterial disease * ***Leptospira iterrogans*** (spirochete) * **notifiable** * transmission: **urine (but not person-to-person)** * ​penetrate skin and enter blood stream * s/s: mistake for other illnesses... * **1st phase:** flu-like symptoms, jaundice * **2nd phase:** **kidney or liver failure or meningitis** * tx: antibiotics * most common in **tropical countries** (50% in HI)

Question 210

viral replication **assembly**

Answer 210

once the parts are made (proteins, genome, etc.) they **"self-assemble"** to make new virons

Question 211

parasitism definition and example

Answer 211

an association in which the parasite lives at the expense of the host i.e. all microbial pathogens

Question 212

antibiotics produced by fungi

Answer 212

* penicillin from *Penicillium notatum* * streptomycin from *Streptomycin griseus*

Question 213

T-cell subsets

Answer 213

Question 214

Adsorption in viral replication

Answer 214

* virus docks with specific cell surface **receptors** * recognition specificity establishes **host range**

Question 215

**Babesiosis** type of disease, casing agents, where its most common in the world, transmission, reservoirs, what does it infect, s/s

Answer 215

* arthropod vector disease * cause - ***Babesia microti*** and ***B. divergens*** * ***​****B. divergens* is fatal if untreated (good tx available) * *B. microti* is seldom fatal in healthy people * **most common in tropical and semitropical areas** * threat to other countries, including U.S. * issue around southern border (reduce with insecticides) * transmission - **ticks** * reservoirs - rodents, cattle, wild animals * **invade RBCs (misdiagnose as malaria)** * s/s - asymptomatic or flu-like; carrier state may develop

Question 216

vector-borne diseases account for what percent of the estimated global burden of all infectious diseases?

Answer 216

17%

Question 217

How has **microbial evolution and adaptation** contributed to emerging infections?

Answer 217

* the appearance of resistant bacteria is due to adaptation and selection, which is accelerated by misuse * prescribing antibiotics for viral illness (i.e. flu or cold) * failure to complete drug regimen

Question 218

what type of virus is this?

Answer 218

zika

Question 219

the chance of acquiring an infection depends on three major factors. what are they?

Answer 219

1. (*n*) **dose** - the number of microbes encountered 2. (*V*) **virulence** - virulence factors 3. (*R*) **resistance** - host immunity

Question 220

viral classificiation

Answer 220

* **host cell:** (microbe, plant, or animal) * bacterial viruses are termed **bacteriophage** or **phage** * issue is that viruses can infect multiple hosts * **clinical:** organ or organ system * issue is that viruses can infect multiple organs and organ systems * **structure:** by type of nucleic acid and shape * start classification with this * **replication cycle** is also used to assist with classification

Question 221

**opisthorchis sinensis** type of disease, cause, where in the body is it found, prevalence, where its found in the world, what can it cause, portal of entry and exit, s/s, dx

Answer 221

* asian/chinese liver fluke * flat worm (fluke) disease * found in **bile duct and gall bladder** (feeds on bile) * **third most prevalent worm parasite** * endemic in **China** (85%), Japan, Taiwan, SE Asia * capable of causing **cancer** * portal of entry: eating **raw or undercooked fish** * portal of exit: feces * s/s: most asymptomatic * dx. eggs in stool

Question 222

sterilization methods (6)

Answer 222

* **dry heat** * 160ºC for 2 hrs, 170ºC for 1 hr * **steam** (delivers heat faster) * 121ºC for \>20 minutes * AT THE CORE * **ethylene oxide gas** for heat sensitive plastics * disadvantage - slow and toxic * **radiation** (e-beam or gamma) * **filtration** * 0.2 micron is considered a sterilizing filter * i.e. tylenol liquid * good for liquids that are heat labile * **chemical sterilization** * hospital solutions * chlorox 5-10%

Question 223

**Community-acquired MRSA infection** how many people are carriers, type of disease, symptoms, tx, prevention

Answer 223

* bacterial contact disease * 2% carry * prevent by good hygience * s/s: **"spider bite"** * tx: drain and antibiotics

Question 224

prevention of prion diseases

Answer 224

* ban against animal products in feed * increased surveillance * diagnosis (protein in CSF)

Question 225

Answer 225

*Leptospira interrogans* causes Leptospirosis - swamp fever soilborne bacterial disease

Question 226

Heterotrophs vs autotrophs (metabolic diversity)

Answer 226

* **Heterotrophs -** metabolize complex organic molecules as a source of energy and carbon * **autotrophs** - use inorganic carbon (CO₂) as an energy source

Question 227

**Hepatitis C virus (HCV)** type of disease, type of virus, s/s, vaccination and tx, transmission

Answer 227

* contact viral disease * **ssRNA** * **chronic bloodborne illness** * transmission: blood, mother to baby, sexual contact * **responsible for almost all blood-transfusion transmitted hepatitis** * **major reason for liver transplants** in U.S. * s/s: 70-80% asymptomatic * mild symptoms similar to HBV * no vaccine, but reasonable treatments

Question 228

**Trichinellosis** type of disease, cause, portal of entry and exit, where its found and prevalence, s/s, dx, tx

Answer 228

* roundworm disease * portal of entry: eating raw or undercooked **pork or wild game** infected with cysts * major reservoirs: **rodents** (pigs feed upon) * **humans typically don't transmit** * portal of exit: feces * **declining in U.S.** * prohibits feeding pigs bad stuff * s/s: flu-like (go undiagnosed) * heavy worm burdens cause cardiac and respiratory problems, death * dx. **muscle biopsy, blood test** * tx. several drugs, but limited effectiveness

Question 229

four ways of artificial active immunization

Answer 229

* **live, attenuated microbes** * TB - BCG vaccine * examples - polio (sabin), measles, yellow fever * concern - reversion to virulent form * **killed (inactivated) microbe vaccines** * heat or chemically-killed * less effective, need booster shots, no risk of infection * examples - polio (salk), plague, influenza, hep A, cholera * **toxoids** * heat or formaldehyde-inactivated exotoxin * maintains ability to induce specific-antibodies * examples - diphtheria and tetanus * **new and experimental vaccines** * **recombinant DNA-vaccine -** virulence gene is cloned into a nonvirulent microbe * **DNA-vaccine:** virulence gene is cloned into a plasmid which expressed foreign gene inside cells

Question 230

Pseudomembranous colitis cause, type of disease

Answer 230

* foodborne and waterborne bacterial disease * ***Clostridium difficile*** (g+, spore-forming bacillus) * major cause of **nosocomial infection** * depletion of normal flora by antibiotic use may allow *C. diff* to "grow out" * **"deadly diarrhea"**

Question 231

stages of microbial disease

Answer 231

* **incubation** - period between initial infection and appearance of symptoms * **prodromal** - period in which early symptoms appear; usually short and not well characterized * **illness** - period during which the disease is most acute and accompanied by characteristic symptoms * **decline** - symptoms gradually subside * **convalescence** - symptoms disappear and recovery ensues

Question 232

cause of TB

Answer 232

* ***Mycobacterium tuberculosis*** * **gram +, non-motile,** lacks outer membrane (**have to acid-fast stain)** * cell wall is thicker than most - hydrophobic * difficult to culture - **slow growing** (24 hrs) * **complex** * **8 subspecies**

Question 233

*Helicobacter pylori*

Answer 233

* defensive virulence strategy * the bacterium that causes peptic ulcers * secretes urease which enables it to survive in the highly acidic environment of the stomach

Question 234

**mumps** type of disease, genome type, vaccine, host, s/s and rare complications, transmission, dx

Answer 234

* airborne viral disease * **ssRNA** * MMR vaccine - 99% decrease since * **humans are the only natural hosts** * s/s: flu-like, many asymptomatic * more common in **children** * infection of **parotid gland** (swelling) * **rare complications** - male sterility; deafness; spread to heart, meninges, and kidney * transmission: airborne or **fomites** * dx: **oral swab or blood -** IgM serologic assay or RT-PCR

Question 235

RZV or ZVL vaccine

Answer 235

2 doses RZV (preferred) \>50 yrs or 1 dose ZVL \>~60 yrs

Question 236

**Hepatitis B virus (HBV)** type of disease, type of virus, at risk, transmission, symptoms, vaccination

Answer 236

* contact viral disease * **dsDNA virus** * at risk: Asian and pacific islanders, MSM, needles * transmission: contact w/ blood, mother to baby * s/s: **silent disease** (decades w/o symptoms) * typical symptoms and jaundice * vaccine (expensive for developing countries) * **3 dose series: birth, 1-2 mos, 6-18 mos**

Question 237

**paragonimus** type of disease, where its found, host, symptoms

Answer 237

* infectious **lung fluke** * **endemic in Asia (not in U.S.)** * **freshwater snails** are intermediate host (54 species) * acute infection * often no symptoms * long-term infection looks like **bronchitis or TB**

Question 238

**candidiasis** type of disease, pathogen, cause, three forms (s/s, at risk, tx, dx, prevention)

Answer 238

* fungal disease * pathogen - ***Candida albicans*** (yeast) * three forms: * **oral** * s/s - red, sore, cracking * dx - scrape and microscope * at risk - immunosuppressed, dentures, broad-spec. antibiotic use * prevention - oral hygiene * tx - oral antifungal med (itraconazole) or topical wash (clotrimazole troches) * **genital** * s/s - itching, burning, "cottage-cheese" discharge, rash * dx - microscopic sample * at risk - pregnancy, diabetes, broad-spec, antibiotic use * prevention - cotton underwear, probiotics * tx - OTC suppositories/creams * **invasive (blood)** * **4th most common hospital-acquired blood stream infection** * s/s - fever, chills, non-specific * dx - blood culture * at risk - ICU, low-birth-weight infants, surgery, central line * prevention - infection control * tx - oral/IV antifungal meds (amphotericin B, fluconazle, echinocandin) * cause - **imbalance of yeast**

Question 239

specific immunity

Answer 239

* produces lymphocytes that respond to foreign antigen * **humoral (antibody-mediated) immunity** * **cell-mediated immunity (CMI)**

Question 240

protective effects of antibodies binding to antigens (humoral immunity)

Answer 240

Question 241

modes of transmission

Answer 241

Question 242

**Blastomycosis** type of disease, pathogen, s/s, where is it found, prevalence, at risk, dx, tx

Answer 242

* fungal disease * pathogen - ***Blastomyces dermatitidis*** * found in soil * transmission - inhale spores * sometimes reportable * **endemic in U.S.** * s/s * **1/2 asymptomatic** * within a few weeks, **flu-like** symptoms * rare - skin and bones * **at risk - everyone** * dx - fungal culture, antigen test * tx - antifungal meds (itraconazole)

Question 243

virulence mechanisms of viruses

Answer 243

* defensive: antigenic variation * influenza - new vaccine every year * offensive: death (lysis) of host cell from * production of lots of replicating viruses * inhibiting protein synthesis * damage to plasma membrane * inhibiting host cell metabolism

Question 244

Answer 244

*Vibrio cholerae* (g- curved rod) secretes exotoxin that cause Cholera intoxication bacterial foodborne and waterborne disease

Question 245

major protozoan diseases (4 food and waterborne, 5 arthropodborne, 1 STD)

Answer 245

Question 246

**severe acute respiratory syndrome (SARS)** type of disease, genome type, pandemic, transmission, vaccine, s/s

Answer 246

* airborne viral disease * caused by **ssRNA coronavirus (SARS-CoV)** * **2002-2003 pandemic** * began in China * no reported cases since 2004 * transmission: airborne and fomites * s/s: flu-like * no vaccine

Question 247

Enzymes

Answer 247

* **​Enzymes** are proteins with activities that allow the invading bacteria to spread throughout the tissues, causing damage in the process * **offensive strategy** * examples: hyaluronidase, collagenase, hemolysins, kinases, leukocidins

Question 248

**bacteria** unicellular, multicellular, or acellular? prokaryotic or eukaryotic? submicroscopic or microscopic? genome? replication? motility? metabolism? cell wall or no cell wall?

Answer 248

* unicellular * prokaryotes * microscopic * DNA genome * replicate by binary fission * cell wall (identify by gram stain) * some motile * metabolism - heterotrophs and autotrophs

Question 249

viruses that cause the **common cold**

Answer 249

* about half of all colds are causes by two RNA viruses: * **rhinoviruses (ssRNA)** * **coronaviruses (ssRNA)** * can also be caused by **adenoviruses (ssDNA)**

Question 250

MMR vaccine

Answer 250

**2 dose vaccine** **12-15 mos** **4-6 yrs** lasts 20 years a quadrivalent vaccine that includes varicella is now available the vaccine is live, attenuated

Question 251

what disease is the leading cause of death worldwide?

Answer 251

tuberculosis

Question 252

different classification systems (taxonomy)

Answer 252

* **Linnaeus** (1700s) classified all organisms as _plant or animal_ * **Haeckel** (1866) had _3 kingdoms_: animals, plants, and protists * **Whittaker** (1969) proposed _5 kingdom_ system: monera, protista, plantae, fungi, animalia * **Woese** (1990) _3 domains_: bacteria, archaea, and eucarya, based on comparisons of _rRNA sequences_

Question 253

animal TSEs

Answer 253

* **mad cow disease** (bovine spongiform encephalitis, BSE) * s/s: drooling, stumbling * UK * **Scrapie** in sheep from scraping against trees, fences * **TSEs** in household cats, deer, elk, mink * **chronic wasting disease (CWD)** in mule deer, white-tailed deer

Question 254

Hippocrates (epidemiology's early history)

Answer 254

* 460-377 B.C. * linked malaria, yellow fever, and swamps * father of medicine and first epidemiologist * movement away from supernatural with no knowledge of the germ theory

Question 255

what type of virus is this?

Answer 255

influenza virus (enveloped)

Question 256

epidemic

Answer 256

* classification of disease * sudden increase in morbidity and mortality above the norm * i.e. plague

Question 257

disease spread by **aedes**

Answer 257

* western equine encephalitis * eastern equine encephalitis * dengue fever * yellow fever * elephantiasis

Question 258

classification of protozoans

Answer 258

protozoans are classified by **locomotion**

Question 259

Answer 259

*Staphylococcus aureus*

Question 260

rotavirus (RV) vaccine

Answer 260

2 dose series 2 mos 4 mos

Question 261

**protozoans** unicellular, multicellular, or acellular? prokaryotic or eukaryotic? submicroscopic or microscopic? genome? replication? motility? metabolism? cell wall or no cell wall? examples?

Answer 261

* unicellular * eucaryotic * microscopic * DNA genome * asexual or sexual replication * no cell wall * some motile (by flagella, cilia, or pseudopods) * metabolism - heterotrophs * examples: malaria, leishmaniasis

Question 262

antigenic variation

Answer 262

* trypanosomes can change surface antigens to avoid host antibodies * example: African sleeping sickness * defensive virulence strategy

Question 263

how to prevent mycoses

Answer 263

* keep healthy and strong immune system * healthy diet and exercise * good hygiene * cautious around mold spore environments * be aware of symptoms

Question 264

direct transmission - vertical transmission

Answer 264

* transplacental * mother to child (breast milk, birth canal)

Question 265

symptoms of the two types of TB conditions

Answer 265

* **symptomatic primary TB** * flu-like, **coughing up blood** * more likely to occur in children, elderly, immunocompromised * **reactivated (secondary) TB** - dormant TB becomes reactivated after decaded * similar to primary, but infection can spread to **bones and joints**

Question 266

foodborne and waterborne viral diseases (3)

Answer 266

Question 267

**gonorrhea** cause, dx, symptoms, tx, rates, presentation, incubation

Answer 267

* caused by bacterium ***Neisseria gonorrhoeae*** * incubation**: 1-14 days** * presentation: * asymptomatic * discharge * dx: site specific * urine * swabs * tx: * **cefixime 400 mg orally in a single dose + azithromycin 1g orally in a single dose** * no sex for 1 wk * rates: * higher in U.S. than UT (but UT increasing by 729%) * whites (UT) * males more infected than females * MSM cases are decreasing * age 25-29

Question 268

**Lymphatic Filariasis** type of disease, cause, where is it found, s/s, dx, tx, transmission

Answer 268

* **"Elephantiasis"** * roundworm disease * **endemic in tropical and subtropical countries** * caused by ***Wuchereria bancrofti*** and ***Brugia malayi*** * **mosquitos** transmit * larvae migrate to lymphatic vessels then blood * dx. microfilariae in blood * tx. **effective single dose treatment** (global eradication possible?) * s/s: asymptomatic, swelling

Question 269

Shigellosis type of disease, cause, issue, death rate, tx

Answer 269

* foodborne and waterborne bacterial disease * *Shigella* (g- bacillus) * tx: rehydration, possible antibiotics * **high death rate in developing countries** * **antibiotic resistance threat**

Question 270

how many people are living with HIV globally?

Answer 270

36.9 million

Question 271

**Staphylococcal food poisoning** microbe, type of disease, where it's found, tx, type of toxin

Answer 271

* *Staphylococcus aureus* (g+ coccus) * foodborne and waterborne bacterial disease * found in human nasal passages (normal flora) * heat stable enterotoxin * s/s within a few hours, very severe, but quick recovery * tx: rest, fluids, meds to calm stomach

Question 272

Four simple steps to prevent foodborne and waterborne bacterial diseases

Answer 272

* **clean** * **separate** * ​don't cross-contaminate * **cook** to right temperature * **chill** * keep fridge below 40ºF

Question 273

Answer 273

*Bacillus anthracis* and endospores

Question 274

What kind of infectious diseases can come about from receiving **blood**?

Answer 274

* HIV * hepatitis * syphilis * malaria * chagas' disease

Question 275

**Leprosy - Hansen's disease** type of disease, cause, transmission, incubation period, at risk, characteristics, treatment, where is this disease

Answer 275

* bacterial contact disease * also spread by droplets * cause: ***Mycobacterium leprae*** (bacillus) * incubation period: 2-10 years * at risk: children * characteristics: * **lepromas** - tumor like skin lesions * **neurological damage** to cooler parts of body (face, hands, feet) * **lost ability to perceive pain** * tx: **6 mo - 2 yr antibiotics** * **rare in U.S.** (most unable to have disease) * widespread in Asia, Africa, South America

Question 276

**cysticercosis** type of disease, cause, portal of entry and exit, what does it infect

Answer 276

* caused by **larval cysts** of tapeworrm ***Taenia solium*** (pork tapeworm) * white, over 8 m long * contain testes and ovaries * infects brain, muscle, other tissue (seizures) * portal of entry: eating undercooked pork that contains larval cysts * portal of exit: feces that pigs then eat

Question 277

**Infectious mononucleosis** type of disease, virus that causes it, transmission, s/s, cancer that can occur, who does it primarily affect, dx

Answer 277

* contact viral disease * caused by **Epstein-Barr virus (EBV) - dsDNA herpes virus** * transmission: contact of saliva and mucus * s/s: many asymptomatic * later symptoms include **swollen glands** * enlargement of lymph nodes and spleen is a serious complication * **Burkitt's lymphoma** - malignant cancer of jaw and abdomen; occurs in Africa * dx: **detect antibodies and abnormal WBCs** * affects primarily age 15-30

Question 278

the HIV life cycle

Answer 278

Question 279

Spanish Flu pandemic of 1918

Answer 279

* most deadly epidemic in history * infected 1/3 of the world; 5% of world died * extreme virulence (dead in 1-2 days) * H1N1 variant

Question 280

inactivated poliovirus (IPV \<18 yrs)

Answer 280

4 dose series 2 mos 4 mos 6-18 mos 4-6 yrs

Question 281

Answer 281

tsetse fly (transmits african sleeping sickness)

Question 282

protein components of blood (active in immunity)

Answer 282

* **antibodies** (immunoglobulins) * recognize and bind to specific foreign antigens (**adaptive** response) * **complement system** - significant **innate** defense mechanism * enhance phagocytosis * bring about lysis of cells * **interferon** * interfere with viral replication * alert other cells * released from virus-infected cells

Question 283

infectious dose (ID) what is the ID of *Vibrio cholerae* and *Mycobacterium tuberculosis*

Answer 283

* minimal number of microbes necessary for infection * more virulent organisms have smaller IDs than less virulent organisms * *Vibrio cholerae* - one million * *M. tuberculosis* - 10

Question 284

nonliving reservoirs

Answer 284

some organisms are able to survive and multiply in nonliving environments, such as soil and water (i.e. *Clostridium* bacteria)

Question 285

disease manifestations of exotoxins

Answer 285

Question 286

Hib vaccine

Answer 286

4 doses 2 mos 4 mos 6 mos 12-15 mos

Question 287

Answer 287

*Shigella* (g- bacillus) causes Shigellosis bacterial foodborne and waterborne disease

Question 288

Robert Hooke

Answer 288

monk who first coined the cell in 1665

Question 289

**Tetanus (lockjaw)** type of disease, where the pathogen is found, cause, treatment, vaccination, toxin, type of tetanus

Answer 289

* soilborne bacterial disease * ubiquitous * **non-communicable disease** * cause: spores of ***Clostridium tetani*** (g+ bacillus) * **Tetanospasmin** (neurotoxin) * second most deadly bacterial toxin * spores germinate and bacilli multipy in deep, anaerobic wounds (i.e. gunshots, animal bites) * **opisthotonos** - extreme contractions of muscles * higher incidence in underdeveloped countries * **VACCINATION IS KEY - DTaP** * tx: emergent! human tetanus immune globulin, antibiotics * **Neonatal tetanus** common in 1st month of life * prevalent in poor nations

Question 290

human TSEs

Answer 290

* **creutzfeldt-jakob disease (CJD)** * occurs in three ways: * **sporadic** (85%) * **hereditary** - associated with gene mutations * **iatrogenic** - contaminated surgical equipment, corneal transplant, blood transfusion (rare) * average age 65; death within 1 year * **kuru** * epidemic in New Guinea 50's and 60's * due to cannibalism * **vCJD** **(variant CJD)** * ​from consuming BSE-contaminated beef * U.K.

Question 291

***pneumocystis* pneumonia** fungus that causes this disease, incidence, mortality rate, at risk, dx, tx

Answer 291

* fungus - ***Pneumocystis jirovecii*** * **one of the most frequent and severe opportunistic infections** * 9% infection rate in HIV/AIDS * **100% mortality if untreated** * **rare in healthy people** * dx - microscope lung fluid or tissue, PCR * tx - **3 wk medication (TMP-SMX)** * **negative side effects** (rash, nausea)

Question 292

Continuum of HIV medical care: methodology PLWDH receipt of care retained in care viral suppression

Answer 292

* **PLWDH:** persons living with HIV * **receipt of care:** \>1 CD4 or viral load * **retained in care:** \>2 CD4 or viral load lab results at least \>3 months apart * **viral suppression:** \<200 copies/mL in blood * no risk of transmission * take **ART daily**

Question 293

what were viruses first described as? who were two people who first worked with viruses and what did they do?

Answer 293

* viruses first described as **"filterable agents"** * Russian **Dmitri Ivanowski** - 1892 * passed a diseased tobacco leaf extract through a filter to remove bacteria. the filtrate caused disease **(tobacco mosaic virus)** * **Wendell Stanley** - 1935 * **crystallized TMV** * electron microscope invented around this time

Question 294

viral STIs

Answer 294

* herpes * HPV * hepatitis

Question 295

cycle of microbial disease

Answer 295

Question 296

subcellular microbes

Answer 296

* viruses * prions

Question 297

two pathways blood cells mature along

Answer 297

Question 298

**swimmer's itch (cercarial dermatitis)** type of disease, normal host, where it's found, s/s

Answer 298

* **form of schistosomiasis** * flat worm (fluke) disease * normally infects water birds or small mammals * not capable of fully developing in man * sporadic in **northern U.S.** * s/s: rash and itching **(immediate immune response)**

Question 299

Soilborne Bacterial Diseases

Answer 299

Question 300

sanitization

Answer 300

kills something (maybe 1 log)

Question 301

How have **technological advances** contributed to increased infectious disease transmission?

Answer 301

* **travel** (arrive at destination before symptoms display) * vectors can also travel in cargo holds * **nosocomial infection** * ​blood and blood products * organ transplants or invasive medical procedures * immunosuppressive therapy or disease (most at risk)

Question 302

prion diseases

Answer 302

* scrapie * kuru * mad cow disease * Creutzfeldt-Jakob disease (CJD)

Question 303

zoonoses

Answer 303

diseases in which animals serve as reservoirs and carriers (i.e. west nile virus)

Question 304

disease manifestations by exotoxins

Question 305

what type of virus is this?

Answer 305

poliovirus (non-enveloped)

Question 306

**Hepatitis D virus (HDV)** type of disease, type of virus, important characteristic, where does it most occur and what is it associated with

Answer 306

* contact viral disease * ssRNA * **defective. cannot replicate without HBV** * **coinfection increases likelihood of liver disease - 20% mortality rate** (highest of all hepatitis viruses) * rare in developed countries * associated with IV drug use

Question 307

antibody (immunoglobulin, Ig) characteristics

Answer 307

* five Ig-types * **IgG, IgA, IgD, IgE, IgM** * each has distinct properties * IgG is the only Ig that can cross the placenta; about 80% of Ig in blood is IgG * all plasma cells initially produce IgM, then "switch" to producing IgG (others switch to IgA or IgE) * T_H cells help B cells produce antibodies by releasing stimulatory proteins called **cytokines**

Question 308

Recommended vaccine for Hib

Answer 308

* one dose at: * 2 months * 4 months * 6 months * 12-15 months

Question 309

infectivity

Answer 309

* the capacity of an agent to produce infection or disease * = number of infected / number of exposed

Question 310

**Whipworm** disease it causes, two main species, portal of entry and exit, s/s

Answer 310

* causes roundworm disease ***Trichuris trichiura*** * live in intestine * portal of exit: **painful passage of stool (mucus and blood)** * **rectal prolapse** * same thing as hookworms! * two main species: * ***Anclostoma duodenale*** (may be transmitted by ingestion) * ***Necator americanus*** * portal of entry: walking barefoot on contaminated soil - **penetrates skin** * s/s: rash or no symptoms * heavy infection - flu-like * **physical and cognitive growth of children** can be affected (malnutrition)

Question 311

mutalism definition and example

Answer 311

a condition in which both species benefit i.e. lichens

Question 312

**PIV (parainfluenza virus)**

Answer 312

* **NOT influenza** * RNA virus * only one strand * **paramyxovirus family** * **"croup" and pneumonia** * s/s and tx similar to EV-D68 and RSV

Question 313

arthropod-borne viral disease (arboviruses)

Answer 313

all transmitted by mosquitos except colorado tick fever

Question 314

**Streptococcus infections** type of disease, microbe that causes it and what is the most virulent species and what does it cause, long term complications, type that is common in children, what is caused by invasive strep, where it resides, how its transmitted, types of infections

Answer 314

* **g+ cocci** * most virulent: ***S. pyogenes*** * ***​*****Erythrogenic toxin**-producing strains cause**scarlet fever**and**"strawberry tongue"** * **streptococcal pharyngitis** (tonsillitis) common in children * airborne bacterial disease * in human nose and throat * transmitted by respiratory droplets or contact with sore or wounds * long term complications for repeated childhood strep infections: * **Glomerulonephritis**, a kidney disease * **Rheumatic fever**, condition involving heart and joints * invasive strep causes: * **toxic shock syndrome** * **necrotizing fasciitis** (25% caused by group A strep) * types of infections: * **group A strep** * **group B strep**

Question 315

two types of virulence factors

Answer 315

* **defensive strategies** - allow microbes to escape destruction by the immune system (i.e. adhesins, capsules, antigenic variation) * **offensive strategies** - result in damage to the host (i.e. exotoxins, endotoxins)

Question 316

What is LD₅₀?

Answer 316

lethal dose - the number of microbes necessary to kill 50% of infected

Question 317

two types of treatment for severe influenza disease

Answer 317

* zanamivir (Relenza) * oseltamivir (TamiFlu)

Question 318

capsid and types

Answer 318

* **capsid** - protein coat made of **capsomere** subunits * capsid types: * **helical** * **polyhedral** * **complex** * make up a **virion** - complete virus particle

Question 319

what is happening with vector borne diseases?

Answer 319

* lack of resources for vector control * DDT can bioaccumulate and become resistant; became illegal in the 1980s and 90s -\> emergence of almost eradicated diseases * lack of political will

Question 320

adhesins (+ examples)

Answer 320

* fixation to cells surfaces and linings at a portal of entry * examples: *Neisseria gonorrhoeae* (attachment to urethral lining using pilli), *Streptococcus mutans* (sticks to surface of teeth), Lactobacillus (digestive tract; capsules), HIV (T cells; spikes), salmonella (flagella), Treponema pallidum (STD; hooks), Giardia (suction discs)

Question 321

Answer 321

*Bacillus anthracis* growth on plate

Question 322

characteristics of infectious disease agents

Answer 322

* infectivity * pathogenicity * virulence * toxigenicity

Question 323

**chlamydia** cause, incubation, presentation, dx, tx, serious health consequences, rates (U.S. vs UT, sex, race, age, increasing or decreasing)

Answer 323

* caused by bacterium ***Chlamydia trachomatis*** * incubation: **~3 weeks** * presentation: * asymptomatic * discharge * dx: site specific * **urine** * **swabs** * **nucleic acid amplification test** * tx: **Azithromycin 1g orally in a single dose** * no sex for 7 days after * serious health consequences: * cervicitis, urethritis, proctitis, pelvic inflammatory disease, ectopic pregnancy, chronic pelvic pain, tubal factor infertility * rates: * U.S. higher than UT * increasing * race - whites in U.S. and blacks in UT * females more affected than males * age 20-24

Question 324

**amphotericin B** (fungizone)

Answer 324

* antifungal drug * "ampho the terrible" * binds ergosterol and destroys cell membrane * toxic

Question 325

spleen

Answer 325

* spongy, fist-sized organ * contains phagocytic cells and mature T and B cells

Question 326

sporadic

Answer 326

* classification of disease * occur only occasionally and in an unpredictable fashion * i.e. tetanus

Question 327

lytic cycle vs lysogenic cycle

Answer 327

two types of infection causes by bacteriophages lysogenic is basically when the genome material is absorbed and hides out (i.e. chicken pox later developing into shingles)

Question 328

lymph nodes

Answer 328

* contribute to immunity * contain B and T cells * site of antibody production * contain phagocytic cells * swollen lymph nodes are an active immune response

Question 329

RSV (respiratory syncytial virus)

Answer 329

* RNA virus * **paramyxovirus family** * **"childhood disease"** * fatal in children if untreated * **tx. supportive** * **Ribavirin** if severe (toxic) * no vaccine

Question 330

development of clinical TB (2 step process)

Answer 330

* **infection** of host with microorganism AND * **development of active disease** * unchecked microbial replication * body's immune response * TB can remain **dormant for 20-30 years** before active disease develops (won't spread)

Question 331

***Staphylococcus aureus*** what does it cause and s/s

Answer 331

* bacterial contact disease * most virulent of staph * can cause - * bacteremia, pneumonia, endocarditis, osteomyelitis * **MRSA** and **Vancomycin-resistant *S. aureus*** are leading causes of nosocomial infections * s/s: * **impetigo** (blister with highly infectious yellow discharge) * **scalded skin syndrome** (blistering skin due to **exfoliative toxin**) * **toxic shock syndrome** (from strains that secrete **TSS-exotoxin**)

Question 332

diagnosis of viral infection

Answer 332

* culturing is too difficult, expensive, and time-consuming * diagnose frequently based on **signs and symptoms** (i.e. rashes) * **definitive tests** - presence of antibody (past or present infection) * **enzyme-linked immunosorbent assays (ELISAs)** * **rapid tests** (i.e. rapid influenza A and B test) * **nucleic acid-based diagnostics** * uses **polymerase chain reaction (PCR)**

Question 333

Koch's postulates

Answer 333

1. **association** - the causative agent must be present in every case of a specific disease 2. **isolation** - the causative agent must be isolated in every case of the disease and grown in pure culture 3. **causation** - the causative agent in the pure culture must cause the disease when inoculated into a healthy and susceptible laboratory animals 4. **reisolation** - the causative agent must be reisolated from the laboratory animal and be identical to the original causative agent

Question 334

severity of infection equation

Answer 334

***D = nV/R***

Question 335

HIV disease progression

Answer 335

* takes years for someone who has HIV to develop AIDS * T cells go down * copies of virus sky rockets * asymptomatic for 5-10 years

Question 336

**peptic ulcers** type of disease, cause, s/s, tx, associated with, how many does it affect, transmission

Answer 336

* bacterial contact disease * spread fecal-oral and oral-oral * cause: ***Helicobacter pylori*** (g- curved/spiral) * produces **urease** -\> breaks down urea into ammonia and CO₂ -\> ammonia neutralizes stomach acid allowing bacteria to survive * **2/3 of world's population infected** * typical s/s: pain, n/v, loss of appetite * tx: antibiotics and **proton pump inhibitor** * associated with **gastric cancer**

Question 337

**chikungunya virus** type of disease, vector, where its found in the world, prevalence, dx, symptoms, tx, mortality

Answer 337

* arthropod-borne viral disease * **emerging threat to Americas** * **mosquito-borne** * RNA viral disease * most people develop symptoms * **fever and severe polyarthralgia (mos to yrs)** * dx - viral culture, RT-PCR, serology * rare mortality * **no vaccine or treatments**

Question 338

**histoplasmosis** type of disease, s/s, dx, tx, where this disease is, transmission, phases

Answer 338

* fungi disease * s/s - flu-like (few days to several weeks after exposure) * last a few weeks to a month * severe in immunosuppressed * **midwest U.S.** * **Ohio and Mississippi** * ~4% mortality * reportable * transmission - **spores circulate in air** after soil is disturbed * **two fungal phases** - inside and outside body * dx - blood test and chest x-rays * tx - itraconazole **3 mos - 1 yr**

Question 339

pathogenicity

Answer 339

* the capacity of the agent to cause disease in the infected host * = # symptomatic / # exposed

Question 340

varicella (VAR) vaccine

Answer 340

2 dose series 12-15 mos 4-6 yrs 2 doses in adulthood

Question 341

Toxoid

Answer 341

* offensive strategy * detoxified toxin that retains antigenicity

Question 342

photosynthetic vs chemosynthetic autotrophs (metabolic diversity)

Answer 342

* **photosynthetic autotrophs** - obtain energy from the sun * these microbes produce most of our oxygen * **chemosynthetic autotrophs** - obtain energy from inorganic compounds

Question 343

how much of the worlds population is infected with latent TB?

Answer 343

1/4 it is a **reemerging** disease and a **global emergency**

Question 344

body site distribution of nosocomial infections

Answer 344

Question 345

what type of virus is this?

Answer 345

smallpox

Question 346

what type of virus is this?

Answer 346

chikungunya

Question 347

**Influenza** type of virus (how many segments), types of influenza, incidence

Answer 347

* RNA virus with 8 segments * influenza A * causes epidemics and pandemics * reservoir - humans, mammals, birds * influenza B * causes epidemics * reservoir - humans, seals * influenza C * mild respiratory illness * reservoir - pigs, humans * incidence * 20% of U.S. gets it yearly (~36,000 die)

Question 348

**imidazoles**

Answer 348

* antifungal drug * ergeosterol biosynthesis inhibitor * micoazole, clotrimazole, ketoconazole

Question 349

cell-mediated immunity (CMI)

Answer 349

* specific immunity * ​production of T lymphocytes directed against antigen * "sensitized" * major defense against **tumor cells and intracellular microbes** * mediated by **CD8⁺ T_C cells** * antigens are digested into **small peptides** * T_C cells recognize these peptide antigens if they are carried on the cell surface and displayed on **MHC** (major histocompatibility) molecules * T_C cells are **clonally expanded** * activated T_C cells produce **perforin** - pore-forming protein that lyses cells

Question 350

viral genome replication for ssRNA

Answer 350

viral parts are not made using host cell functions

Question 351

**Legionnaire's disease (legionellosis)** type of disease, cause, where the bacteria is found, transmission, s/s and death, at risk, tx

Answer 351

* Aiborne bacterial disease - Lower respiratory tract infection * ***Legionella pneumophila*** (g- bacillus) * reportable. U.S. * found in warm water * transmission: inhalation, NOT person-to-person * typical s/s * death usually by shock and kidney failure (5-30% rate) * at risk: old people, smokers, respiratory problems * tx: antibiotics

Question 352

How do ecological disturbances contribute to increase in infectious diseases?

Answer 352

* **Deforestation** and human intrusion into remote ecosystems * _increase contact_ with animals and insect vectors (i.e. HIV/AIDS) * see _migration of displaced animals and vectors_ into villages (i.e. chagas' disease, rabies, leishmaniasis, schistosomiasis) * _zoonosis_ and the species leap * **climactic changes** * **​**increase incidence and distribution of infectious disease (vector, microbe, or both increase due to rising temperature) * **natural disasters** * floods in S. Africa -\> increase in mosquitos carrying malaria, increase in cholera * drought in E. Africa -\> famine and malnutrition

Question 353

ID₅₀

Answer 353

minimum does to establish 50% infection

Question 354

What makes a microbe?

Answer 354

* **size** * **metabolic diversity** * **​**heterotrophs, autotrophs (photosynthetic and chemosynthetic) * important for _preventing microbes from getting nutrients_ * important for _diagnosing_ * **requirement for oxygen** * **prokaryote vs eukaryote**

Question 355

human normal flora is composed mainly of commensal bacteria. where is normal flora found in the body? how does it benefit us?

Answer 355

conjuctiva, nose, mouth, skin, stomach, small intestine, large intestine, urethra benefits us be preventing other pathogens; doesn't harm

Question 356

mechanical and chemical barriers in immunity

Answer 356

* **skin** - first line of defense * **stomach acidity** - inhibitory to most microbes * **mucous membranes** * **cilia -** propel microbes into pharynx where they are swallowed and expelled * **lysozyme** - enzyme that destroys cells walls of bacteria * found in saliva, tears, sweat * **phagocytosis** * **professional phagocytes - monocytes, neutrophils, macrophages** * located strategically throughout the body * **inflammation** * four signs - **redness (rubor), heat (calor), swelling/edema (tumor), pain (dolor)** * **​vasodilation** * **chemoattraction** - phagocytes attracted to inflamed tissue

Question 357

Answer 357

flee

Question 358

How is HIV spread?

Answer 358

Question 359

antiseptic

Answer 359

sanitizer or disinfectant used on the body

Question 360

pneumococcal polysaccharide (PPSV23) vaccine

Answer 360

1 dose \>65 yrs

Question 361

**St. Louis encephalitis** type of disease, where its found in the world, reservoirs, s/s

Answer 361

* encephalitis-causing arboviruses * found in most of U.S. * reservoirs - birds * s/s - headache, fever

Question 362

Diptheria type of disease, cause, what does it form, s/s, tx, complications

Answer 362

* airborne bacterial disease * caused by an **exotoxin** produced by ***Corynebacterium diptheria*** (g+ bacillus) * kills epithelial cells. forms leathery **pseudomembrane** * s/s: weak, sore throat, fever, swollen glands * death by _suffocation_ may result for thick coating building up in nose and throat * may diffuse through blood and cause _damage to heart_ * tx: antitoxin and antibiotics * vaccination: DTaP * 1 out of 10 diphtheria patients die, even with tx

Question 363

**Microbial evolution and diversity** what was discovered 3.5 byo? what was the early atmosphere like? evolution of photosynthetic microbes?

Answer 363

* **bacteria were the first life-forms on earth** * discovered _fossilized bacteria in stromatolites_ 3.5 byo * early atmosphere was _devoid of oxygen_ * photosynthetic microbes evolved to use sunlight, water, and CO₂ to produce oxygen and carbohydrates 2 byo

Question 364

what type of virus is this?

Answer 364

ssRNA coronavirus (SARS-CoV) causes severe acute respiratory syndrome (SARS)

Question 365

**Eastern equine encephalitis** type of disease, reservoirs, where its found in the world, prevalence

Answer 365

* encephalitis-causing arbovirus * occurs in eastern half of the U.S. * Florida, Georgia, Massachusetts, NJ * affects humans, horses, and some birds * infected horses are a "dead end" * not a lot of cases

Question 366

Edward Jenner

Answer 366

* late 1700s * observations of cowpox led to smallpox vaccine (1st vaccine)

Question 367

**PrP^c** vs. **PfP^sc**

Answer 367

* PrP^c * ^​normal, "non-virulent" protein * unknown function * encoded by *PrP* gene * PrP^sc ("PrP-scrapie") * abnormal, miscfolded, infectious form of PrP

Question 368

**Dermatophytes** what is causes, s/s, tx, dx, where it lives, prevention, at risk, prevalence

Answer 368

* **"ringworm" or "tinea"** * fungi that causes **skin, hair, and nail infections** * lives in moist areas * s/s - red, scaly, **ring-shaped rash** * at risk - very common, contact sports * prevention - good hygiene * dx - scrape area and microscope * tx - topical antifungal meds, some oral

Question 369

contact viral disease (other than STDs and bloodborne) (6)

Answer 369

Question 370

most common type of food poisoning

Answer 370

Staphylococcal food poisoning

Question 371

**food-borne infection** what is it and give examples

Answer 371

* **bacteria grows in you** * produce e**nterotoxin** * examples: salmonella, vibrio cholera, shigella, listeria, hepatitis A * self-resolving * if prolonged, treat with antibiotics

Question 372

two major components of the immune system

Answer 372

* **nonspecific** or **innate** * inherent, present before infection * **specific** or **adaptive** * **​**develops in response to infection

Question 373

**African trypanosomiasis (sleeping sickness)** type of disease, causing agent (2), where its found in the world, prevalence, tx, s/s, transmission, ID, unique characteristic

Answer 373

* arthropod vector disease * cause - ***Trypanosoma brucei gambiense*** (west and central Africa) and ***T. brucei rhodesiense*** (east Africa) * *T. brucei gambiense* on the rise in areas of **Sudan** * **declining in Africa** * transmission - **tsetse fly** * reservoirs - animals and humans * I**D is 500, but ~50,000 parasites in a single bite** * s/s - **red chancre, lethargic** (invades blood, spinal fluid, brain) * over months or years, personality chances, confusion, coma * if untreated, death * **antigenic variation** * tx - pentamidine **drug therapy** (CSF exam for 2 years)

Question 374

airborne viral diseases

Answer 374

Question 375

secondary immune structures

Answer 375

* lymph nodes * spleen * tonsils and adenoids * peyer's patches * located in lining of GI, respiratory, and urinary tracts * protect against microbes entering through mucosal surfaces

Question 376

classification of helminths

Answer 376

* flat worms (digenian flukes) * tapeworms (cestodes) * round worms (nematodes)

Question 377

viral genome replication for dsRNA

Answer 377

Question 378

**HPV** cause, prevention, presentation, incubation, diagnosis

Answer 378

* caused by **human papillmavirus** * prevention: **vaccine** * presentation: * genital warts * cervical cellular abnormalities * anal cancer * incubation: * 3 wks to several months (genital warts) * several months to years (cervical cell abnormalities) * dx: **pap smear**

Question 379

Cell Theory

Answer 379

* (Schleiden, Schwann, and Virchow) * the cell is the fundamental unit of all organisms * all organisms are unicellular or multicellular * all cells are fundamentally alike in structure and metabolism

Question 380

Answer 380

tick

Question 381

**Group A strep** what does it cause, tx

Answer 381

* causes: * strep throat, impetigo (skin infection) * severe can cause pneumonia, necrotizing fasciitis, TSS * tx: * antibiotics

Question 382

**"sick building syndrome"** type of disease, pathogen, s/s, when it occurs, at risk

Answer 382

* environmental fungi disease * pathogen - ***Stachybotrys chartarum*** * affects immunosuppressed and allergy sensitive * occurs after natural disasters - * **Hurricane Katrina** * **Joplin, Missouri tornado** * s/s - * respiratory * rare - **necrotizing soft tissue infections**

Question 383

Why does Tokyo, Japan have reduced levels of infectious disease despite high population density?

Answer 383

serious public health control

Question 384

How is the hospital environment a source of nosocomial infection?

Answer 384

* patients are ill with weakened immune system * hospital fosters development of antibiotic-resistant strains of bacteria * invasive procedures, catheters, needles, and tubes, facilitate the direct transmission of microbes

Question 385

Campylobacteriosis cause

Answer 385

* ***Campylobacter jejuni*** (curved g- bacillus) * most frequent cause of bacterial diarrhea in the U.S. * **many isolates are antibiotic resistant** * bacterial foodborne and waterborne disease

Question 386

commensalism definition and example

Answer 386

one species benefits but the other neither benefits nor is harmed i.e. normal flora

Question 387

M protein

Answer 387

* in streptococcal cell walls and interferes with phagocytosis * defensive virulence strategy

Question 388

HPV vaccine

Answer 388

11-12 yrs HPV-female 2 or 3 doses 19-26 yrs HPV-male 2 or 3 doses 19-21 yrs

Question 389

How do STIs facilitate HIV transmission?

Answer 389

* disrupt epithelial/mucosal barriers * increase HIV target cells in genital tract * increase expression of HIV co-receptors * induce secretion of cytokines (increase HIV shedding)

Question 390

**Fungi** unicellular, multicellular, or acellular? prokaryotic or eukaryotic? submicroscopic or microscopic? genome? replication? motility? metabolism? cell wall or no cell wall?

Answer 390

* unicellular (yeast) or multicellular (molds) * eucaryotic * microscopic (yeast only) * DNA genome * asexual or sexual replication * cell wall * non-motile * metabolism - heterotrophs

Question 391

**Ebola virus** type of disease, virus type, s/s, dx, tx, vaccine, transmission, reservoir, host

Answer 391

* contact viral disease * RNA virus causes the zoonosis **Ebola hemorrhagic fever** * **5 subspecies** * **sporadic; high fatality** * **bats are most likely reservoir** * infects humans ("incidental"), monkeys, chimps * s/s: flu-like and hemorrhaging * transmission: **direct (person-to-person)** * **biosafety level 4** * isolation of disease. PPE * dx: detect antibodies * tx: **IV fluids, maintain O₂ status and BP** * no vaccine currently available (blood transfusions from survivors being explored)

Question 392

Answer 392

Enterotoxigenic *E. coli* bacterial foodborne and waterborne disease

Question 393

how does **urbanization** contribute to an increase in infectious diseases?

Answer 393

* combines with poverty that decreases hygiene, more malnutrition, rodent increase, less safe drinking water, and less public health infrastructure * more polution

Question 394

white blood cells (leukocytes)

Answer 394

* **granulocytes** (innate response) * **neutrophils** - key phagocytic cells * **basophils** - rich in granules of histamine * **eosinophils** - seen in worm infections, allergies * **agranulocytes** * **monocytes** - key phagocytic cells, innate response * **lymphocytes** - the crucial cells of adaptive response * **T lymphocytes** * **B lymphocytes** - producers of antibodies