Listeria infection causes few or no symptoms in healthy adults and children.
However, it can be very serious for people whose immune systems are weakened by disease or illness as well as pregnant women and their unborn children, newborn babies and the elderly.
Health authorities advise people with compromised immune systems, and their families, that they need to consider taking precautions against contracting listeriosis.
Listeria may be found in certain types of foods, especially ready-to-eat foods that have not been stored or handled correctly after being produced or cooked.
Unlike most microorganisms, listeria can multiply in some foods such as soft cheeses, smoked salmon and sandwich meats even when stored under refrigeration for a long time.
Therefore you can reduce your risk of contracting listeriosis by avoiding specific foods and by practising good food hygiene.
The foods to avoid include:
- cold meats, including chicken, from delicatessen counters and sandwich bars, and packaged sliced ready-to-eat meats
- pre-prepared or pre-packaged fruit and vegetable salads including those available from buffets and salad bars
- chilled seafood such as raw oysters, sashimi and sushi, smoked ready-to-eat seafood (such as smoked salmon) and cooked ready-to-eat peeled prawns in salads, sandwiches or prawn cocktails
- soft, semi-soft and surface ripened cheeses such as brie, camembert, ricotta, blue and feta
unpasteurised dairy products
- refrigerated types of patÃ© and meat spreads
- soft serve ice cream
What can I do?
Listeria infection can be minimised by good food handling practices in the home. Here are some suggestions on how you can minimise your risk;
- Thoroughly washÂ fruits andÂ vegetables before using
- Keep high risk foods below 4Â°C (susceptible individuals should avoid altogether)
- Use food within its â€˜use by dateâ€™
- Refrigerate leftovers promptly and use within 24 hours, or freeze
- Participate in good food hygiene and clean utensils when preparing food
- Reheat food until it is piping hot (Listeria is killed off at boiling point).
Also remember to always wash your hands before preparing or eating food.