Bacteria & viruses in food
Food contaminated with harmful bacteria and viruses can cause stomach upset, nausea, vomiting and diarrhoea, or worse. Learn about foodborne illnesses and how to avoid them.
Contaminated food can make you sick
Foodborne illness is the term used when you are sick because of food and drink containing harmful bacteria, viruses, fungi, parasites, toxins or natural contaminants. It's often referred to as food poisoning. If you think you have an illness caused by food, seek medical attention from your doctor.
Symptoms of foodborne illness
Symptoms may include:
- nausea or vomiting
- diarrhoea or dysentery
- allergic reactions
- stomach cramps or pains
- fever or chills
- muscle or joint aches.
Symptoms may show up in as little as 20 minutes – or it could take several weeks for you to become sick. Often it is not the last food you ate that caused your illness.
If you have symptoms of foodborne illness
If you have low immunity and you think you have an illness caused by something you've eaten, contact your doctor right away. Foodborne illness can be mild but sometimes, especially for people with low immunities, it can be life-threatening.
Notifiable foodborne illness
Some foodborne illnesses are notifiable under the Health Act 1956, which means your doctor or diagnostic laboratory must tell a Medical Officer of Health of your illness.
The Medical Officer of Health is responsible for identifying the source of your illness, if possible. If it's a foodborne illness, they'll work with MPI to minimise its effect in the community.
Types of bacteria and viruses
Find out more about the types of bacteria that cause foodborne illness on these pages:
- Bacillus cereus
- Escherichia coli (E. coli) (STEC)
- Listeria monocytogenes
- Other harmful bacteria and viruses, including Yersinia
Reduce your risk of getting sick
You can easily pass harmful bacteria and viruses on to another person. To avoid getting sick, you need to prepare, handle, cook, and store food carefully.
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