Preventing viral gastroenteritis

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Viral gastroenteritis occurs more commonly during cooler months of the year. The most common culprits are norovirus and rotavirus. The symptoms are diarrhoea and vomiting mainly, sometimes also headache, fever, and abdominal cramps. In general, symptoms begin 1 – 2 days following infection and, depending on the type of viruses causing the illness, may last for 1 – 10 days. 

If you experience symptoms, seek medical advice from your doctor promptly. Antibiotics are usually of no value in treatment for viral infections, and should not be taken without a doctor’s prescription. Drink enough fluids to avoid dehydration, but avoid sugary drinks as they may make symptoms worse. Oral vaccines for infants are available for preventing rotavirus infection.  Parents can approach their family doctors for further advice and information.

Prevention is better than cure. Viral gastroenteritis can be transmitted through consuming contaminated food or water, or contact directly or indirectly with vomitus or faeces from infected persons. Norovirus can also be transmitted by aerosol spread with contaminated droplets of splashed vomitus. To prevent viral gastroenteritis, strict observance of environmental, food, and personal hygiene is important. 

Food hygiene:

  • Eat only thoroughly cooked food, particularly seafood and shellfish.
  • Drink only boiled water from the mains or bottled drinks from reliable sources. Avoid drinks with ice of unknown origin.
  • Susceptible populations (e.g. pregnant women, infants, the elderly and people with weakened immune systems) should avoid eating foods that are consumed raw, such as raw oyster and pre-packaged salads.

Personal Hygiene:

  • Perform hand hygiene frequently, especially before handling food or eating, and after using toilet and changing diapers. 
  • If suffering from fever, vomiting or diarrhoea, refrain from work or school, and avoid handling food for susceptible populations.

Environmental Hygiene:

  • After using the toilet, put the toilet lid down before flushing to avoid spreading germs.
  • Clean and disinfect toilets used by infected persons and the soiled areas.
  • Properly clean any vomitus/ faeces spillage with disposable wipe, and disinfect contaminated areas with 1:49 diluted household bleach (mixing 1 part of 5.25% bleach with 49 parts of water). For metallic surface, disinfect with 70% alcohol. Wear gloves and a surgical mask throughout the disinfection procedure. Soak all cleaning tools in 1:49 diluted household bleach for 30 minutes, then rinse thoroughly and air dry before reuse. Wash hands thoroughly afterwards.

For details, please visit the thematic webpage of Centre for Health Protection (, and the website of Centre for Food Safety (