Viruses of Diarrhea

Finish Rotavirus

Calici

Characteristics

Genogroups

Norovirus

Snow Mountain Like Virus

Sapporo-like virus

Hepatitis E virus

Icosahedral

Similar to Rotavirus

Viral replication/assembly in cytoplasm

Particles released by death of host cell

Clinical

Rotavirus symptoms

How does duration and severity differ?

Duration, severity is less

Flu-like symptoms

Fever

Headache

Malaise

Anorexia

Myalgia

Abdominal cramps

Diagnosis

No commercial kit

Research

Immunoassay

Molecular

Electron microscopy

Epidemiology

Transmission

Fecal-oral

Incubation period

1-3 days

Syllabus says "10-50 hrs"

Time

Seasonality

Place

Person

Mostly early childhood

Exception?

Norwalk virus: after 1st decade

Prevention

Similar to Rotavirus

Treatment

ORT

Supportive therapy

Rota

Reoviridae

Characteristics

Hub-wheel shape

Segmented genome

11 segments

Double-shelled capsid

Outer shell necessary for attachment

Genetics

Serology

Replication

Pathophysiology

VP4, VP7

Clinical

Fever

Vomiting

Explosive watery diarrhea

Metabolic acidosis

Diagnosis

Latex Agglutination / EIA

CheapReadily available

Electron Microscopy

Not readily available

Culture

Expensive

Epidemiology

Time

Winter

Place

Nosocomial

DCC

DCC = Day Care Center

Transmission

Fecal-oral

Fomites

Shedding

Symptomatic, asymptomatic, or both?

Symptomatic

Asymptomatic

Water-borne

Respiratory?

Incubation period

1-3 days

Prevention

Vaccine

Rotateq

Rotatrix

Chemical agents

Lysol

Chlorinated phenols

95% EtOH

Hand-washing

Contact isolation

Treatment

ORT

IV/NG feeding

Enteric Adeno

Characteristics

Icosahedral

Linear DS DNA

Capsid

12 pentons

antennae projecting from vertices

Serotypes 40, 41

..cause what illness?

GI-tis

Clinical

Viral GI-tis

2nd most common cause of viral GI-tis in hospitalized patients

Mild respiratory symptoms

Otherwise indistinguishable

Rotavirus symptoms

Diarrhea: 5-12 daysVomiting: 2-3 days

Diagnosis

Commercial kit

DNA probe

Electron microscopy

Molecular

Molecular techniques used by research labs

Not detected by routine techniques

Tissue culture is gold standard for adenoviruses, but enteric adenoviruses (serotypes 40 and 41) are not detected by routine tissue culture techniques.

Epidemiology

Person

Children < 2 y.o.

Group with highest incidence

Place

Time

Seasonality

Incubation period

8-10 days

Longer than most enteric viruses

Prevention

Vaccine for military

CAVEAT: Only covers serotypes 4, 7, and 21

Hand washing

Contact isolation

Treatment

No specific AV

Astro

Characteristics

Star-shaped

7 serotypes

Clinical

Rotavirus GI-tis

Symptoms indistinguishable from Rotavirus-induced gastroenteritis except disease is milder

Duration: 3-7 days

Median duration of viral excretion: 20 days

Diagnosis

No commercial kit

Research

Tissue culture

Immunoassay

Molecular

Electron microscopy

Epidemiology

Time

Incubation period

12 hrs - 3 days

Seasonality

Winter

Similar to Rotavirus

Place

Person

All age groups

Highest attack rate?

Children < 2 y.o.

Prevention

Similar to Rotavirus

Treatment

ORT

Supportive