export_gi viruses ii (1)

Question 1

Poliovirus family and features

Answer 1

Picornavirus
+ssRNA

Acid tolerant

Question 2

Three poliovirus serotypes

Answer 2

P1, P2, P3

Question 3

Poliovirus transmission

Answer 3

Fecal-oral route

Question 4

Poliovirus incubation period

Answer 4

6-20 days

Question 5

Clinical features of poliovirus

Answer 5

95% asymptomatic
Abortive poliomyelitis

Nonparalytic aseptic meningitis

Flaccid paralysis

Question 6

Abortive poliomyelitis

Answer 6

Sore throat
Fever

Vomiting and abdominal pain

Constipation

Question 7

Nonparalytic aseptic meningitis

Answer 7

Stiffness in back, neck, legs

Lasts 2-10 days

Question 8

Poliovirus diagnosis

Answer 8

Virus in stool

Isolates must be sequenced (wild type or vaccine strain)

Question 9

Original polio vaccine

Answer 9

Inactivated vaccine (Salk strain)

Question 10

Later polio vaccine

Answer 10

Trivalent, live attenuated oral polio vaccine (Sabin strain)

Since it can cause VAPP, we switched back to the inactivated in 2000

Question 11

VAPP

Answer 11

“Vaccine-Associated Paralytic Poliomyelitis”

1 in 2 million vaccines will revert to a neurotropic strain that causes CNS symptoms

Question 12

Poliovirus prevention

Answer 12

Inactivated vaccine

Question 13

Viruses that can cause gastroenteritis

Answer 13

Rotaviruses
Noroviruses

Adenoviruses

Astroviruses

Question 14

Features of all viruses that cause gastroenteritis

Answer 14

Non-enveloped

Fecal-oral transmission

Question 15

Differences between viral and bacterial gastroenteritis

Answer 15

Viral - similar incidence throughout world, 1-3 days, vomiting is prominent, non-bloody diarrhea is common, diagnosis of exclusion
Bacterial - more common in poor hygiene regions, hours-7 days, vomiting less prominent but found with preformed toxins, prominent diarrhea frequently with blood, diagnosis with culture

Question 16

The biggest concern with viral gastroenteritis

Answer 16

Dehydration due to watery diarrhea

Rapid, weak pulse, sunken eyes, no tears, skin tenting, lack of urination

Question 17

Virus that causes the highest incidence of gastroenteritis in children

Answer 17

Rotavirus

Question 18

Rotavirus incubation period

Answer 18

1-3 days

Question 19

Rotavirus symptoms

Answer 19

Vomiting and diarrhea for 4-7 days, occasional cough, coryza

Some patients have a fever

Question 20

Rotavirus pathogenesis

Answer 20

<10 particles needed to initiate disease
Malabsorptive diarrhea

Produces a toxin (NSP4) that causes Ca2+ release

Question 21

Diagnostic sign of rotavirus

Answer 21

Villi blunting

Question 22

Diagnosis of rotavirus

Answer 22

EIA from stool sample

EM, or RT-PCR (less common)

Question 23

Treatment of rotavirus

Answer 23

Rehydration therapy

Question 24

Prevention of rotavirus

Answer 24

Sanitize toys, wash hands, IgA in colostrums, vaccines

Question 25

Rotavirus vaccine

Answer 25

Two live attenuated, oral vaccines

Protective against G1-G4, G9

Question 26

Norovirus family and features

Answer 26

Caliciviridae family
Non-enveloped

+ssRNA

Question 27

Norovirus pathogenesis

Answer 27

Binds to specific histo blood-group Ags

Question 28

Norovirus incubation

Answer 28

24-48 hours

Question 29

Norovirus symptoms

Answer 29

Nausea, vomiting, diarrhea for 24-60 hours

Low grade fever in about half of patients

Question 30

Norovirus transmission

Answer 30

Fecal-oral

Question 31

Adeovirus family and features

Answer 31

dsDNA
Naked capsid

Serotypes 40 and 41 cause gastroenteritis

Question 32

Adenovirus incubation

Answer 32

8-10 days

Question 33

Adenovirus symptoms

Answer 33

Watery, non-bloody diarrhea for 7-8 days, may be accompanied by fever and vomiting

Question 34

Adenovirus diagnosis

Answer 34

Ab based assay

Question 35

Sapovirus family

Answer 35

Also Caliciviridae (like Norovirus)

Question 36

Astrovirus features

Answer 36

Star-shaped

+ssRNA