Rotavirus

Rotavirus is a genus of viruses in the family Reoviridae that cause gastroenteritis. Rotaviruses are non-enveloped, icosahedral particles about 70 nanometers in diameter and have a segmented double-stranded RNA genome. The virus has a wheel-like appearance under electron microscopy, which gives it its name. The genome consists of 11 segments encoding structural and nonstructural proteins, including VP4 and VP7, which define the G and P types.

In humans, rotavirus infections mainly affect infants and young children, though older children and adults can be infected, especially in settings with close contact. The virus is transmitted primarily by the fecal-oral route, but fomites and contaminated food or water can contribute. Rotavirus can persist on surfaces and in the environment, and illness tends to be seasonal in temperate climates, with winter peaks.

Clinical presentation usually includes abrupt onset of vomiting followed by watery diarrhea, abdominal pain, and fever. Dehydration can be severe, particularly in infants, and may require oral rehydration or intravenous fluids. Most cases resolve within a week. Diagnosis is typically clinical, but can be supported by laboratory testing such as antigen detection in stool or nucleic acid testing.

Treatment is mainly supportive, focusing on rehydration and maintenance of nutrition. Zinc supplementation is recommended in many settings. Antibiotics are not effective against viruses. Prevention relies on vaccination and good hygiene. Two main vaccines, Rotarix and RotaTeq, are used in many countries and are given to infants as part of routine immunization schedules; vaccination reduces the incidence of severe rotavirus disease and hospitalizations.

Global burden remains high in low- and middle-income countries where access to care is limited, though vaccination programs have substantially reduced severe disease and mortality. Ongoing surveillance monitors rotavirus strains and vaccine impact.