Gastroenteritis and food poisoning are a public health concern

Acute gastroenteritis is a highly contagious disease that many of us have experienced. Te Mana Ora | Community and Public Health can investigate cases of gastroenteritis if groups of people are affected at the same time or if a food premise, event or location is implicated.

Sources and symptoms of Acute gastroenteritis

Acute gastroenteritis is caused by bacteria, viruses, parasites or chemicals and can be spread:

  • By ingesting contaminated food (food poisoning); or
  • By ingesting contaminated water; or
  • From animals; or
  • Directly from one person to another person; or
  • From contaminated objects in the environment.

The common symptoms of diarrhoea, vomiting and stomach cramps are caused by the digestive system being inflamed. These symptoms can last from a few hours, days, weeks or months – depending on the cause.

What to do if you think you have food poisoning

Contact the Communicable Disease Team at Te Mana Ora | Community and Public Health if you think you have food poisoning. A staff member will complete a questionnaire with you over the phone. The information will used to determine the likely source and cause of your illness. You may need to provide poo samples (and food specimens if available) to assist in the investigation.

Most people think that the last food they ate caused their illness. However symptoms can take from 30 minutes to over 10 days to start.

Te Mana Ora | Community and Public Health may follow up food poisoning cases where a food premise, event or location is implicated. Further investigation is then carried out and the local Council or Ministry for Primary Industries (Food Safety Section) notified of an issue if needed.

Food safety guidance for pregnant people

Your immunity levels are lower than usual when you are pregnant. So you’re more at risk of getting food poisoning or other diseases from food.

Eating safely when you are pregnant will help protect you and your developing baby’s health. Foodborne illness can make you and your baby unwell, and in extreme cases can cause:

  • serious illness;
  • premature birth;
  • stillbirth; or
  • the death of newborn babies.

Some high-risk foods should be avoided while you’re pregnant such as raw milk or dairy products. Other foods need to be prepared carefully to reduce harmful bacteria, such as processed meats or seafood.

It is also important to follow basic food safety guidelines when preparing and storing food. This helps prevent harmful bacteria from getting in your food.

Dealing with gastroenteritis outbreaks in aged care and education settings

Cases of acute gastroenteritis are increasing in health care facilities and education settings in New Zealand. These institutional outbreaks are concerning as the very young and elderly are at greater risk of being seriously affected. Te Mana Ora | Community and Public Health staff can provide assistance to deal with these infectious diseases when they happen and also guidance to limit the impact on everyone involved.

Staff need to act quickly if a rest home suddenly has an increase in diarrhoea or vomiting. Staff should take the following steps:

  • Seek infection control advice from an Infection Control Nurse at a Community Laboratory.
  • Contact the Communicable Disease Team at your local Community and Public Health office to notify the outbreak to the Medical Officer of Health.
  • Download the Outbreak Notification and Illness Log forms. Email the completed forms to your local Community and Public Health office at the end of the outbreak.

The Communicable Disease Team can provide further advice or assistance if needed.


Food safety guidance for individuals and events


Download or order resources from the Community Health Information Centre.


Contact the Communicable Disease staff at your local office to report possible food poisoning:

Ph: +64 3 364 1777

Ph: +64 3 687 2600

Ph: +64 3 768 1160

For questions on food safety, call:

Ministry for Primary Industries
0800 693 721

This includes:

  • Food Complaints including foreign objects or undeclared allergens in food within our region;
  • Food Recalls;
  • Imported Food;
  • Food Safety Programmes; and
  • Food Labelling.

Contact an Environmental Health Officer at your local council if you want to report a ‘dirty’ food premise or unhygienic practices of food handlers.

Don't eat raw or undercooked mussels.

Understanding the risks of raw milk

Raw milk has not been heat treated to kill harmful bacteria such as Campylobacter, Listeria and toxin-producing strains of E. coli.

There’s no way to tell by taste, sight or smell if raw milk will make you sick.

People most likely to get sick from drinking raw unpasteurised milk are young children, pregnant women and those with weakened immune systems.

Page last updated: 10/11/2023

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