GI Viruses

Question 1

viruses that enter the GI must be ________, resistant to ______ in the GI tract, and generally transmitted via ________ and must be able to survive in environment

Answer 1

acid stable
enzymes
fecal-oral route

Question 2

5 GI viruses?

Answer 2

1. picornaviruses (enteroviruses)
2. rotaviruses
3. calciviruses
4. astroviruses
5. adenovirus

Question 3

polio, coxsackie A and B, echoirus, enterovirus, hepA, and rhinoviruses all belong to what virus family?

Answer 3

picornavirus (enterovirus)

Question 4

• small icosahedral viruses, family picornaviridae
• positive polarity RNA
• translated as polyprotein
• relatively stable

Answer 4

enteroviruses

Question 5

picornaviruses replicate rapidly, in as little as _____ hours

Answer 5

6

Question 6

_______ rather than immune pathology is responsible for causing disease pathology in enteroviruses

Answer 6

viral replication

Question 7

_______ antibody is transitory but can prevent the initiation of infection, and _____ antibody prevents viremic spread to target tissue preventing disease

Answer 7

secretory

serum

Question 8

• humans the only host
• tropism for central nervous system
• extensive necrosis of neurons in gray matter, affecting anterior horn of spinal cord

Answer 8

poliovirus

Question 9

90% of polio infections are asymptomatic, where virus infection limited to?

Answer 9

oropharynx and gut

Question 10

5% of polio infections result in _________, characterized by headache, fever, malaise, sore throat, and vomiting

Answer 10

abortive polio/minor illness

Question 11

1-2% of polio infections results in _________, where virus progresses to CNS and meninges, get back pain and muscle aches

Answer 11

non-paralytic polio/asceptic meningitis

Question 12

0.1 to 2% of infections lead to _______, where virus spreads to anterior horn cells of spinal cord and motor cortex

Answer 12

paralytic polio

Question 13

enteroviruses as a group cause the most cases of what?

Answer 13

asceptic meningitis

Question 14

• Salk vaccine
• good stability and transport, safe in immunodeficient, no risk of vaccine related disease
• lack of gut immunity, need booster, needs to be injected, higher community immunization levels needed

Answer 14

inactivated poliovirus vaccine

Question 15

• Sabin vaccine
• effective, lifelong immunity, induction of secretory antibody response similar to natural infection, no need for boosters, her immunity attenuated virus circulating in community
• risk of vaccine associated poliomyelitis, spread of vaccine to contacts without their consent, unsafe for immunodeficient

Answer 15

live oral polio vaccine

Question 16

common coxsackie and echovirus infections?

Answer 16

herpangina (painful ulcers on palate and tongue), hand foot mouth disease, pleurodynia (fever and intense pain chest area and abdomen), myocardial and pericardial infections, viral asceptic meningitis

Question 17

herpangina caused by _________ virus, causing soft palate lesions, fever, sore throat, anorexia, vomiting

Answer 17

coxsackie A

Question 18

hand foot mouth disease caused by ________ virus, patient can but mildly febrile, self limiting

Answer 18

coxsackie A

Question 19

known as devil’s grip, associated with coxsackie B virus, unilateral low thoracic peluritic chest pain, average of 4 days, treat with analgesics

Answer 19

pleurodynia

Question 20

myocarditis caused by coxsackie B virus –> infiltrate of ______

Answer 20

lymphocytes

Question 21

• presenting symptom may be headache, neck stiffness and photophobia, younger children may have diarrhea, rash, and cough
• erythematous rash, maculopapular, and vesicular
• fever up to 5 days
• anorexia, nausea, vomiting
• sore throat
• caused by coxsackie A and B, must be differentiated from bacterial

Answer 21

asceptic meningitis

Question 22

• segmented, double stranded RNA

- 11 segments are rotaviruses

Answer 22

reoviridae

Question 23

rotavirus inner capsid antigen ______ has the group determinants, outer capsid antigens ________

Answer 23

VP6

VP7, VP4

Question 24

rotavirus:
spread by _______ route
______ infection of intestinal epithelium causes loss of electrolytes and prevents readsorption of water
-large amounts of ______ are released during diarrheal phase

Answer 24

fecal oral
cytolytic
virus

Question 25

incubation period of rotavirus?

Answer 25

about 3 days

Question 26

rotavirus enterotoxin incorporated into the ER membrane, actively secreted from the apical membrane of polarized epithelial cells, attributed to anion secretion, virus release, calcium mobilization, protein kinase C activation, golgi independent vesicle trafficking for virus exit

Answer 26

NSP4

Question 27

ingestion of rotavirus particles leads to infection of adsorptive ________ cells, stimulation of ________, and enterotoxin _____ ; leading to osmotic diarrhea

Answer 27

intestinal villus cells enteric nervous sytem NSP4

Question 28

quick easy ways to detect rotavirus in stools

Answer 28

EIA or latex agglutination

Question 29

the segmented genomes of rotavirus can undergo ______, initial infection and recovery from initial rotavirus infection rarely induces ______

Answer 29

genetic reassortment | sterilizing immunity

Question 30

live attenuated (rotateq, rotarix) rotavirus vaccines have been developed, not meant to induce ________ but to prevent _______

Answer 30

sterilizing immunity | severe disease

Question 31

- small non-enveloped viruses - (+) ssRNA - cause outbreaks of gastroenteritis, generally resolves within 48 hours - species: norwalk virus, norovirus

Answer 31

calciviruses

Question 32

- transmittted by fecally contaminated water or food, or aerosolization - most common cause of gastroenteritis in the world - generally self limting within 48 hours - outbreaks on cruise ships, etc

Answer 32

norwalk virus

Question 33

diagnosis of norwalk virus done by?

Answer 33

RT-qPCR assays

Question 34

- small RNA viruses - assoc'd with cases of endemic gastroenteritis, usually in young children and neonates - responsible for up to 10% of cases of viral gastroenteritis - diagnosed by electron microscopy only

Answer 34

astroviruses