What should you know about microbial food poisoning?

Microbes can enter food during growing, preparation, storage or serving. They may irritate the gut or release substances that disturb digestion. Symptoms can include diarrhoea, nausea, vomiting, abdominal cramps and fever. The timing varies with the organism and the amount consumed, so symptoms may begin soon after eating or later.

Most uncomplicated illness improves with rest and fluids. Antibiotics are not suitable for every cause, and taking an anti-diarrhoeal medicine may be unhelpful in some situations, especially with fever or blood in the stool.

Take frequent small sips of water or an oral rehydration solution. If vomiting settles, try light meals and return gradually to your usual diet. Avoid preparing food for other people while you have symptoms, wash your hands carefully, and clean shared bathroom surfaces. Keep a note of when symptoms began, what you ate, and how often you are passing stool or vomiting.

A clinician can assess dehydration and decide whether testing, prescription treatment or fluids through a vein are needed. Oral rehydration therapy may be enough when you can drink; IV fluid therapy may be considered when dehydration is significant or drinking is not possible.

Seek urgent medical help for confusion, fainting, severe weakness, very little urine, inability to keep fluids down, severe or worsening abdominal pain, blood in vomit or stool, or a high fever with marked illness. Contact a clinician promptly if symptoms are prolonged, you are pregnant, or the person affected is a young child, an older adult, or someone with a weakened immune system.

Ask which signs suggest dehydration, whether a stool test is useful, which medicines to avoid, and when it is safe to return to work, school or food preparation.