What is a foodborne illness outbreak?

An outbreak may involve people who ate the same meal, used the same water source, visited the same venue, or became ill after contact with a common food handler. Similar symptoms such as diarrhoea, vomiting, abdominal pain, nausea, or fever can provide a clue, but only an investigation can identify the source.

People may become ill at different times because the cause and amount of exposure vary. The suspected food may have been eaten earlier, and not everyone exposed will feel unwell.

Contact a healthcare professional and describe the shared exposure, meal location, timing, and symptoms. Keep packaging, receipts, or leftover food sealed if available, and do not serve suspected leftovers. Drink fluids and use oral rehydration solution when needed. Wash hands and avoid preparing food for others while symptomatic.

Seek urgent care for severe dehydration, fainting, confusion, blood in vomit or stool, severe abdominal pain, persistent vomiting, or a rapidly worsening illness. Get advice early for a young child, older adult, pregnancy, or weakened immune system. A suspected outbreak should be reported through the local public-health route or with help from your clinician.

Ask whether testing is needed, how long you may be infectious, and how to reduce household spread. Give a clear list of affected people, shared foods, symptom onset, travel, and any hospital visits.