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Foodborne illnesses - what they are and how to avoid them

The more common foodborne illnesses:
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Bacteria, fungi, parasites, viruses and toxins may contaminate food and cause stomach upset, nausea, vomiting and diarrhoea or worse. Learn about foodborne illnesses and how to avoid them.

Foodborne illness is the term used when you are sick because of contaminated food. If you think you have an illness caused by food, contact your doctor right away.

Some foodborne illnesses are ‘notifiable’ which means your doctor must tell the local public health service of your illness. The public health service will identify the source of the illness and prevent it from spreading.

You can easily pass bugs from one person to another. To avoid getting sick, you need to prepare, cook and store food carefully.

Two of the most important ways to reduce your risk from contaminated food are by following the:

• 4Cs rule – clean, cook, cover, chill [NZ Foodsafe Partnership]

• 20+20 hand washing rule before and after handling food [NZ Foodsafe Partnership]

Meet the bugs – the causes, symptoms and how long a foodborne illness may last

The more common foodborne illnesses:

Campylobacter (bacteria)

Campylobacter is the bacterial organism that causes the gastro-intestinal illness campylobacteriosis. Outbreaks of campylobacteriosis have been linked to undercooked chicken, unpasteurised milk, chicken live pate and drinking water.

Campylobacter, cooking and food – information for consumers

Salmonella (bacteria)

Salmonella is a bacteria that causes mild to severe gastroenteritis in people and animals. Salmonella mainly lives in the gut. It can be found on most foods of animal origin such as meat or eggs, also foods that have been washed in contaminated water or touched by infected food-handlers.

Salmonella, cooking and food – information for consumers

Escherichia coli or E. coli (bacteria)

E. coli bacteria live in the intestines of some healthy cattle, sheep and pigs as well as deer and seagulls.

These bacteria have been found in undercooked meat (usually minced) contaminated during the slaughter process. Other sources of the infection could be raw vegetables, untreated water, unpasteurised milk, and handling farm animals that are shedding the bacteria. It can also be spread by poor hand hygiene.

Frequently asked questions about Escherichia coli O157:H7

Detailed information about Escherichia coli O157:H7 [PDF: 33K, 5 pages]

Detailed information about Escherichia coli non-O157, shiga toxin producing (STEC) [PDF: 24K, 4 pages]

Bacillus cereus (bacteria)

Most illnesses from Bacillus cereus are foodborne, caused by eating infected rice or starchy foods such as potato flakes and pasta. The bacteria arise when these foods have been cooled too slowly, or not correctly stored in a refrigerator.

Detailed information about Bacillus cereus [PDF: 27K, 3 pages]

Listeria monocytogenes (bacteria)

Listeria bacteria are widespread in the environment and can be found around the home, in farm livestock, pets and wild animals. Most foods associated with outbreaks are unprocessed foods, such as raw diary products, meat, poultry and fish and ready-to-eat products, such as deli meats and salads, soft cheeses and foods with a long shelf life.

Listeria, cooking and food – information for consumers

Norovirus (virus)

Noroviruses are very contagious and hardy viruses that cause severe stomach upsets (gastroenteritis). You may become infected after eating food that’s been exposed to sewage in some way, such as oysters eaten raw which were taken from polluted water.

Frequently asked questions about Noroviruses

Detailed information about Noroviruses [PDF: 27K, 4 pages]