Humans are always the source of infection and viruses may be present in the gastro-intestinal tract.

Many outbreaks are caused by people vomiting in closed environments. There is a high risk of person-to-person spread due to the large number of virus particles present in the vomit and infected aerosols in the atmosphere.

Where the illness is associated with food the cause is often attributed to a food handler working whilst unwell or recovering from infection.

Food handlers showing symptoms must be excluded from work until 48 hours after symptoms have ceased;

Food handlers must take extra care with personal hygiene when family members are suffering gastro-enteritis or similar symptoms;

Food handlers and other staff should ensure that their hands are thoroughly clean and washed as frequently as necessary;

Care staff in residential or nursing homes and cleaning staff in hotels, should wear designated protective clothing when dealing with symptomatic residents. This should include over-clothing and gloves which should be put on before entering a sick-room and removed prior to leaving that room at which time they should be placed into a sealable bag and either disposed of or laundered at a high temperature;

Residents of hotels and care homes should be isolated to prevent person-to-person contact and reduce the risk of spreading the infection;

Faecal matter and vomit should be cleaned up as quickly as possible to avoid creating further aerosols and be removed in closable containers to prevent the spread of infection. Containers should be disposed of, where possible, or else sanitized after use. It is advisable to use absorbent granules when dealing with spillages. Finally the area should be cleaned and disinfected; Those who are symptomatic should have designated towels and utensils to reduce the risk of spreading the infection. These items should be boil-washed after use.

Environmental hygiene should include frequent disinfection of door handles, all surfaces within toilets/wash rooms. Areas where spillage has occurred, i.e. in lounge/dining rooms/hallways, become highly infected areas and should be well ventilated to allow a fresh air flow to remove virus particles. In some incidents it may be worth while considering environmental fogging to destroy viruses.