Structure: Family Reovirus (Respiratory, Enteric, Orphan viruses), a medium sized virus (60-80 nm), double-stranded, segmented RNA genome (11 segments), non-enveloped, double layered icosahedral capsid.
• Infection occurs most frequently in children (6 mo to 2 yrs), but also occurs in adults. Accounts for approximately 50% of all cases of diarrhea in children requiring hospitalization.
• Transmission occurs via the fecal-oral route with an incubation period of <48 hrs.
• Stable in the environment due to resistance to detergents, pH extremes and freeze-thawing.
• Occurs year round in tropical areas, however, in temperate regions Rotavirus infections peak during Dec-April.
• At least 3 factors are felt to play a role in the pathogenesis of rotavirus diarrhea: direct effect of an enterotoxin (NSP4), loss of brush border enzymes and activation of the enteric nervous system.
• Within the intestine, proteolytic enzymes enhance infectivity.
• In children: Typical symptoms include vomiting, nonbloody diarrhea, abdominal pain and fever. Average duration of illness in children is 3-8 days, however, the virus may be shed for weeks following illness.
• In adults: Typically mild disease and generally occurs in household members of affected children. Rotavirus has been reported as a cause of outbreaks in colleges and long-term care facilities.
• More severe symptoms (high fever, dehydration, seizures) may be seen in immunocompromised patients.
• Immunity is not completely protective; reinfection may occur, however, the symptoms are generally mild.
• Laboratory findings are usually normal. A mild to moderate number of fecal leukocytes are present in approximately 30% of stool samples.
• Stool sample for rapid detection of viral antigen via enzyme immunoassay (EIA) or latex agglutination. Molecular techniques such as PCR (more sensitive) are not readily available.
• Bacterial, other enteric viruses and noninfectious causes of diarrhea.
• No specific medications available; supportive management of symptoms and complications, especially dehydration.
Prevention and Control:
• Oral Vaccine – live, attenuated rotavirus (currently 2 brands available)
• Stringent hand hygiene
• Isolation of known cases