RNA Virus

Question 1

Under PICORNAVIRIDAE

Answer 1

Poliovirus
Coxsackie virus (A and B)
ECHO (Enteric Cytopathic Human Orphan) virus
Rhinovirus
Hepatitis A virus (Enterovirus 72)

Question 2

Poliovirus

Transmission
Pathogenesis
Spectrum of disease
Diagnosis
Prevention

Answer 2

Transmission: Oral-fecal route
Pathogenesis: replicates in motor neurons in anterior horn of spinal cord causing paralysis
Spectrum of disease: Poliomyelitis and Meningitis
Diagnosis: Cowdry type B and intranuclear inclusion
Prevention: Salk and Sabin Vaccination

Question 3

Coxsackie virus (A and B)

Transmission
Spectrum of disease

Answer 3

Transmission: Oral-fecal route

Spectrum of disease:
- Coxsackie A virus (Herpangina, acute hemorrhagic conjunctivitis, HFMD, and aseptic meningitis)
- Coxsackie B virus (Pleurodynia, severe generalized disease of infants, pericarditis and myocarditis, and aseptic meningitis)

Question 4

ECHO (Enteric Cytopathic Human Orphan) virus

Transmission
Spectrum of disease

Answer 4

Transmission: Oral-fecal route
Spectrum of disease:
- aseptic meningitis,
- URTI,
- febrile illness (with or without rash),
- infantile diarrhea and
- hemorrhagic conjunctivitis

Question 5

Rhinovirus

Transmission
Pathogenesis
Spectrum of disease

Answer 5

Transmission: Aerosol droplets and hand-to-nose contact
Pathogenesis: replicate better at 33°C than at 37°C -> affect primarily the nose and conjunctiva rather than the lower respiratory tract (acid-labile killed by gastric acid)
Spectrum of disease: Common cold

Question 6

Hepatitis A virus (Enterovirus 72)

Transmission
Pathogenesis
Spectrum of disease
Diagnosis
Treatment and Prevention

Answer 6

Transmission: Oral-fecal route
Pathogenesis: replicates in the GI tract and then spreads to the liver during a brief viremic period.
Spectrum of disease: Hepatitis A infection
Diagnosis: anti-HAV IgM (most useful)
Treatment and Prevention: administration of immune globulin during IP and vaccination (killed virus)

Question 7

HERPEVIRIDAE

Answer 7

Hepatitis E virus

Question 8

Hepatitis E virus

Transmission
Spectrum of disease
Diagnosis
Notes

Answer 8

ansmission: Oral-fecal route
Spectrum of disease: hepatitis E
(infection is frequently subclinical and fulminant hepatitis in pregnant women)
Diagnosis: patchy necrosis (liver biopsy)
Notes: E = (Expectant mother, Enteric, and Epidemic)

Question 9

CALICIVIRIDAE

Answer 9

Norwalk virus (Norovirus)

Question 10

Norwalk virus (Norovirus)

Transmission
Spectrum of disease

Answer 10

Transmission: Oral-fecal route
Spectrum of disease: viral gastroenteritis (most common in adult)

Question 11

REOVIRIDAE

Answer 11

Rotavirus

Question 12

Rotavirus

Pathogenesis
Spectrum of disease
Treatment and Prevention:

Answer 12

Pathogenesis: Villous destruction with atrophy
Spectrum of disease: Viral gastroenteritis (childhood: ”white stool diarrhea”)
Treatment and Prevention: rotavirus vaccine

Question 13

Incubation: 1-3 days
Duration: 5-7 days
Seasonality: Predominantly in winter and fall
Transmission: Fecal-oral route and respiratory

Answer 13

Rotavirus

Question 14

Incubation: 12-48 hours
Duration: 1-4 days
Seasonality: Year-round, but especially in winter
Transmission: Fecal-oral route aerosolization, respiratory transmission, food, fomites, and water

Answer 14

Norovirus

Question 15

Incubation: 1-2 days
Duration: 3-4 days
Seasonality: Year-round
Transmission: Fecal-oral route

Answer 15

Sapovirus

Question 16

Incubation: 4-5 days
Duration: 5-6 days
Seasonality: Predominantly in winter
Transmission: Fecal-oral route and water

Answer 16

Astrovirus

Question 17

Incubation: 3 - 10 days
Duration: 6-9 days
Seasonality: Predominantly in summer
Transmission: Fecal-oral route

Answer 17

Enteric adenovirus (40 and 41)