Rotavirus is a virus that causes gastroenteritis (inflammation of the stomach and intestines). The rotavirus disease causes severe watery diarrhea, often with vomiting, fever, and abdominal pain. In babies and young children, it can lead to dehydration (loss of body fluids).
The incubation period for rotavirus disease is approximately 2 days. The disease is characterized by vomiting and watery diarrhea for 3 to 8 days, and fever and abdominal pain occur frequently. Immunity after infection is incomplete, but repeat infections tend to be less severe than the original infection.
Rotavirus has a characteristic wheel-like appearance when viewed by electron microscopy (the name rotavirus is derived from the Latin rota, meaning "wheel"). Rotaviruses are non-enveloped, double-shelled viruses. The genome is composed of 11 segments of double-stranded RNA, which code for six structural and five nonstructural proteins. The virus is stable in the environment.
Diagnosis may be made by rapid antigen detection of rotavirus in stool specimens. Strains may be further characterized by enzyme immunoassay or reverse transcriptase polymerase chain reaction, but such testing is not commonly done.
The primary mode of transmission is via fecal-oral route. Because the virus is stable in the environment, transmission can occur through ingestion of contaminated water or food and contact with contaminated surfaces or objects. In the United States and other countries with a temperate climate, the disease has a winter seasonal pattern, with annual epidemics occurring from December through June. The highest rates of illness occur among infants and young children. Adults can also be infected, though disease tends to be mild.
Rotavirus is the leading cause of severe diarrhea in infants and young children worldwide. Globally, it causes more than a half a million deaths each year in children younger than 5 years of age.
There are currently two Rotavirus vaccines pre-qualified by the World Health Organization. These are Rotarix, produced by GlaxoSmith Kline and available in 3 different presentations, and Rotateq, produced by Merck Sharp & Dohme Corp. WHO has recommended that rotavirus vaccination be included in all national immunization programmes.
Vaccinated and unvaccinated children may develop rotavirus disease more than once because there are many different types of rotavirus and because neither vaccine nor natural infection provide full immunity (protection) from future infections. However, second infection tends to be less severe than the first rotavirus infection.