Food poisoning bacteria: what to know

Some bacteria multiply in food; others produce toxins that irritate the digestive system. Contamination can happen during growing, handling, cooking or storage. Symptoms vary by germ and may begin soon after a meal or later. Bacterial food poisoning can present with nausea, abdominal pain, diarrhoea, vomiting or fever, but symptoms alone cannot name the organism. A clinician may ask about shared meals, travel, sick contacts and the appearance of your stool.

Replace losses with frequent sips of water or oral rehydration solution. Continue eating small, plain meals if you can, and avoid alcohol while symptoms continue. Wash hands with soap and water after using the toilet and before touching food; clean contaminated surfaces and do not share towels. Avoid antibiotics unless prescribed, because they are not useful for every cause and may be unsuitable in some situations. Oral rehydration therapy supports fluid and salt replacement; IV fluid therapy may be used when dehydration is significant or drinking fails.

Get medical advice for bloody diarrhoea, severe abdominal pain, persistent fever, repeated vomiting, worsening weakness or symptoms that are not settling. Urgent care is needed for fainting, confusion, inability to drink, very little urine or other signs of marked dehydration. Children, older adults, pregnant people and those with long-term conditions can become unwell more quickly and should seek advice early.

Ask whether testing is needed, how to choose an oral rehydration product, which medicines are appropriate, and when you can safely return to work or prepare food.