Rotavirus is a highly contagious virus that infects the intestine causing gastroenteritis (vomiting and diarrhoea) and fever, predominantly in infants and young children.
Without immunisation, almost all children in the world are infected by rotavirus before five years of age. It is recognised as the most common cause of diarrhoea (loose stools) and dehydration in infants and young children in all countries. Adults can also become infected.
Rotavirus was first identified in 1973 and was named rotavirus because of the wheel-like appearance of the virus.
Before a vaccine to protect against rotavirus was added the the New Zealand Immunisation Schedule, 9 out of 10 New Zealand children would have contracted rotavirus by the age of three years. Although death from rotavirus infection in New Zealand was very rare, 1 child in 43 had been hospitalised with rotavirus infection by 5 years of age.
Rotavirus is spread by the faecal-oral route (from the stool to the mouth usually through contaminated fingers) and generally occurs in winter and early spring. Spread of infection within families and institutions is common, as large amounts of rotavirus are present in the stools of infected individuals. The virus survives on hard surfaces for several days, and contamination of hands, hard surfaces, toys, utensils and other objects is relatively easy.
The illness begins with the sudden onset of vomiting and/or watery diarrhoea, which can last from three to seven days. Fever and abdominal pain may also occur. Adult symptoms are usually mild. In some cases the person infected has no symptoms but can still infect others.
Small frequent sips of water or age-appropriate hydration fluids (oral rehydration therapy) can help prevent/manage dehydration.
Rapid and severe deterioration can occur, and many children will require medical intervention and hospitalisation for this. Signs of dehydration include:
Children can start eating solids whenever they feel ready. Bland foods, e.g. toast or dry biscuits are good to start with.
The major risk is dehydration from vomiting and diarrhoea.
Most infections occur in infants and children aged between 3–24 months. The first infection after 3 months of age is usually the most severe.
Rotavirus infection increases the risk of bowel obstruction, known as intussusception, particularly in infants under one-year of age.
Death from rotavirus infection is extremely rare in New Zealand.
An oral rotavirus vaccine is available free and recommended for young babies to commence before 15 weeks of age.
The spread of rotavirus can be minimised by thorough hand washing, especially after changing nappies or cleaning up vomit, after using the bathroom, before preparing food and before eating, and by cleaning toys and hard surfaces regularly. The virus may be shed in the stool of an infected child for up to 10 days after the onset of symptoms.
Children with diarrhoea or vomiting should not attend school or childcare centres until diarrhoea or vomiting has stopped for at least 48 hours.
Purifying water supplies and a focus on good hand hygiene are important but alone are unlikely to substantially reduce the incidence of this disease.