Listeria and food - advice for people at risk

What is Listeria?

Listeria are bacteria that can cause a serious illness called listeriosis in some people. While Listeria infection is uncommon and causes few or no symptoms in healthy people, it can be very dangerous for those people at risk.

Listeriosis is usually caused by eating food contaminated by certain types of Listeria bacteria. The Listeria bacteria are found widely in nature. Storing contaminated foods, even in the refrigerator, may allow the Listeria bacteria to grow.

The bacteria may be present in raw foods or may contaminate food after it has been cooked or processed.

Who is at risk?

People at higher risk of listeriosis include:

• pregnant women, their unborn and newborn children;
• older people (generally considered to be persons over 65-70 years);
• people of all ages whose immune systems have been weakened by disease or illness, for example cancer, leukaemia, AIDS, diabetes, liver or kidney disease; and
• anyone on medication that can suppress the immune system, for example, prednisone or cortisone, including organ transplant patients.

If you have any concerns about whether you are at risk please consult your medical practitioner.

What are the symptoms?

In persons at risk, symptoms may include fever, headache, tiredness, aches and pains. Less common symptoms are diarrhoea, nausea and abdominal cramps. Symptoms may progress to more serious forms of the illness, such as meningitis and septicaemia.

Symptoms in pregnant women may be mild, but listeriosis can result in miscarriage, premature birth or, in rare cases, stillbirth.

If you have any concerns about symptoms or illness please consult your medical practitioner

What precautions should I take if I am at risk?

The food industry and governments work together to ensure our food is safe. However, if you or anyone in your household is in the at risk group, it is important you reduce your risk by taking a few simple precautions. These include:

• preparing, storing and handling food hygienically;
• avoiding certain foods which have a higher risk of Listeria contamination; and
• being careful about food prepared by others.

Eat freshly cooked or freshly prepared foods

Ideally, eat only freshly cooked food and well-washed freshly prepared fruit and vegetables. However, leftovers can be eaten if they are refrigerated promptly and kept no longer than a day. It's important that you do not eat food if there is any doubt about its hygienic preparation or storage.

Cook foods thoroughly

Thorough cooking of food kills Listeria bacteria. Ensure food is cooked thoroughly.

Reheat foods to 'steaming' hot

If you plan to eat previously cooked and refrigerated leftovers, only keep them in the refrigerator for a day and reheat them thoroughly to steaming hot. This will kill Listeria bacteria.

When reheating food, especially in a microwave, make sure the food is steaming hot throughout.

Make safer food choices

As a general rule, avoid perishable foods (need to be refrigerated) that have been prepared well in advance and are to be eaten without further cooking.

The tables overleaf list some examples of higher risk foods and safer alternatives. You should avoid consuming these higher risk foods, especially if you are unsure about how they have been prepared, stored and handled. Food is safe if you cook it or reheat it to steaming hot throughout and serve it hot.

Avoid ready-to-eat food from salad bars, sandwich bars, delicatessens and smorgasboards

Ready-to-eat foods from salad bars may have been prepared and refrigerated some time before they are put on display. Listeria bacteria may have grown in these foods so they are best avoided.

Foods on open display in delicatessen counters are more likely to become contaminated by Listeria than foods that are sold packaged by the manufacturer. Avoid these foods.

Avoid foods that are past their 'best before' or 'use by' date

Choose and consume foods well within their 'use by' or 'best before' date. Once opened, eat promptly.

Do not eat refrigerated foods that are past their 'use by' or 'best before' date.

Only buy ready-to-eat hot food if it's steaming hot

If you buy ready-to-eat hot food, for example a cooked chicken, make sure it's very hot and either eat it or refrigerate it promptly on arriving home. Use it within a day.

If eating out, order hot meals

Choose menu items that are cooked to order and served hot. Do not eat food that is served lukewarm. It is best to avoid smorgasbords and salad bars. If this isn't possible, choose the hot foods only.

Good food hygiene

Take some simple food hygiene steps to reduce the risk of foodborne disease.

• Thoroughly wash and dry your hands before preparing food, particularly before preparing ready-to-eat food.
• Keep your refrigerator clean and operate it below 5°C.
• Wash knives, cutting boards and kitchen appliances and dry thoroughly after handling raw food to prevent contamination of cooked and ready-to-eat foods.
• Thoroughly wash and dry raw fruit and vegetables before eating or juicing.
• Thaw ready-to-eat frozen food in the refrigerator or microwave - don't thaw at room temperature.
• Thoroughly cook all raw meat, chicken and fish.
• Don't leave foods to cool on the bench or stove top. Put them in the refrigerator after the steam has gone.
• If you are keeping food hot, keep it very hot (60°C or hotter). Keep cold food cold (5°C or colder).
• Thoroughly reheat food until it is steaming hot.
• Keep stored foods covered.
• Store raw meat separately from cooked and ready-to-eat food in the refrigerator. Store it below other foods so that there is no chance it will drip onto other foods.

For more information on good food hygiene visit the Food Safety Information Council website www.code.asn.au

Making safer food choices

Listeria is managed by hygienic preparation, storage and handling of food. Avoid consuming higher risk foods, especially if you are unsure that hygienic practices have been followed. These tables list some examples of higher risk foods and safer alternatives. 

Examples of some higher risk foods:

Safer alternatives:

Food Standard Australia New Zealand (FSANZ) ensures safe food by developing effective food standards for Australia and New Zealand.

We are an integral part of a strong food regulatory system operating between governments at all levels in Australia and New Zealand.

We develop food standards with advice from other government agencies, input from stakeholders and food regulatory policies endorsed by the Food Ministers Meeting. FSANZ and the food industry work together to ensure our food is safe.

Our decisions are open and accountable, based on the rigorous scientific assessment of risk to public health and safety.

In Australia, we develop food standards for the entire food supply chain, from primary production through to manufactured food and retail outlets.

Download a copy of this brochure (PDF 32kb)