What are the risk factors for gastroenteritis?

Gastroenteritis is inflammation of the stomach and intestines, commonly caused by viruses and sometimes bacteria or parasites. Germs can spread through unwashed hands, shared surfaces, close contact, unsafe food or contaminated water. Norovirus spreads readily in households, schools, healthcare settings and other crowded places.

Young children, older adults and people with weakened immunity can become dehydrated more quickly. Travel, childcare attendance, living in shared accommodation and preparing food for others may increase exposure. A risk factor raises exposure or vulnerability; it does not prove that a particular germ caused the illness.

Wash hands with soap and water after using the toilet, changing nappies and before preparing or eating food. Clean contaminated surfaces, avoid sharing towels and stay home while vomiting or having diarrhoea. Handle food safely, use reliable drinking water and take travel-health advice when needed.

If illness starts, take frequent small sips of fluid; oral rehydration solution can replace lost water and salts. Continue suitable foods as tolerated. Avoid preparing food for other people while infectious, and follow local clinical advice about returning to school or work.

Seek medical advice for signs of dehydration such as very little urine, dry mouth, dizziness or unusual sleepiness, especially in a child or older adult. Get urgent care for blood in stool, severe abdominal pain, confusion, fainting, repeated vomiting or inability to keep fluids down. Persistent diarrhoea after travel or in a person with reduced immunity also needs review.

Ask: How can I recognise dehydration? Should I use oral rehydration solution? Does anyone exposed at home need extra precautions? Do my medicines or health conditions increase risk? When can I safely return to work, school or childcare?