The listeria bacteria is found absolutely everywhere. It likes the cold, propagating well at 32° Fahrenheit (0° centigrade), so it can thrive in refrigerated as well as non refrigerated foods.
If you put infected food (meat that has not been properly cooked, for example) in your fridge, you can be almost certain it contains listeria bacteria.
Many people mistake flu symptoms (headaches, fever and stiffness) for benign or acute listeriosis. In acute cases the nape of the neck stiffens, and delirium and even fatal coma can result. Generally though, symptoms are confined to severe diarrhoea and a bad cold.
Persons with immune deficiencies have to be extremely careful not to contract listeriosis, since their natural defence mechanism does not function, giving the bacteria free rein to propagate. The quality of cheese, ham, fish, meat, cooked dishes and even packaged lettuce should be closely monitored.
Initial symptoms of listeriosis include:
– prolonged severe indigestion – headaches
– fatigue – weak legs
If you have developed one or a number of these symptoms after eating what you suspect may be contaminated food, seek the advice of a qualified health specialist.
– Wash your hands before handling food.
– Make sure knives and cutting boards are washed, especially after handling raw foods.
– Keep uncooked meat separate from vegetables and cooked or ready-to-eat meals.
– Try to avoid leftovers as much as possible.
– If you do eat leftovers, heat them beforehand.
– Never re-freeze food that has already thawed.
– Cook meat and other animal foods well (that includes eggs).
– Wash raw vegetables and herbs thoroughly
Despite all these precautions, the best defence against listeria is a strong immune system.
The question of non-pasteurized milk
Are products made from non-pasteurized milk (certain types of cheese, for example) more likely to contain listeria bacteria? The answer is no. Tests have shown that pasteurized milk – as well as processed meat-contains just as much listeria as non-pasteurized milk. People who decide to eat only vegetables in order to avoid listeria contamination overlook the fact that many vegetables can host the bacteria as well. Potatoes, radishes, the outside leaves of lettuce and cabbage, etc., can all contain listeria, although strangely enough none has been found on grated carrots.