Viruses belonging to the family of Reoviridae.
Transmission is primarily by the faecal–oral route, directly from person to person, or indirectly via contaminated fomites. A respiratory mode of transmission has also been proposed.
Nature of the disease
Rotavirus causes an acute gastroenteritis in infants and young children and is associated with profuse watery diarrhoea, projectile vomiting and fever. Rapid dehydration requiring rehydration therapy can occur, especially in very young infants. The virus replicates in the enterocytes of the small intestine, causing extensive damage to the microvilli and resulting in malabsorption and loss of fluids and electrolytes.
Rotaviruses are found worldwide. They are the leading cause of severe, dehydrating diarrhoea in children under 5 years globally: outpatient visits are estimated at more than 25 million and hospitalizations attributable to rotavirus infections at more than 2 million each year. WHO estimates that in 2008 453 000 (420 000 494 000) child deaths occurred due to rotavirus gastroenteritis worldwide. Fatal outcomes occur predominantly in low-income countries. In temperate climates, the incidence of rotavirus gastroenteritis typically peaks during the winter season, whereas in tropical settings this type of gastroenteritis occurs year round. Reinfection of older children and adults is common, although reinfections are usually sub-clinical.
Risk for travellers
The risk for adult travellers is negligible since most individuals will have good immunity through repeated exposures early in life. Children under the age of 5 years are at risk.