Foodborne listeriosis is one of the most serious and severe foodborne diseases. It is caused by the bacteria Listeria monocytogenes. It is a relatively rare disease with 0.1 to 10 cases per 1 million people per year depending on the countries and regions of the world. Although the number of cases of listeriosis is small, the high rate of death associated with this infection makes it a significant public health concern.
Unlike many other common foodborne diseases causing bacteria, L. monocytogenes can survive and multiply at low temperatures usually found in refrigerators . Eating contaminated food with high numbers of L. monocytogenes is the main route of infection. Infection can also be transmitted between humans, notably from pregnant women to unborn babies.
L. monocytogenes are ubiquitous in nature and found in soil, water and animal digestive tracts. Vegetables may be contaminated through soil or the use of manure as fertilizer. Ready-to-eat food can also become contaminated during processing and the bacteria can multiply to dangerous levels during distribution and storage.
Food most often associated with listeriosis include:
- foods with a long shelf-life under refrigeration (L. monocytogenes can grow to significant numbers in food at refrigeration temperatures when given sufficient time); and
- foods that are consumed without further treatment, such as cooking, which would otherwise kill L. monocytogenes.
In past outbreaks, foods involved included ready-to-eat meat products, such as frankfurters, meat spread (paté), smoked salmon and fermented raw meat sausages, as well as dairy products (including soft cheeses, unpasteurized milk and ice cream) and prepared salads (including coleslaw and bean sprouts) as well as fresh vegetables and fruits.
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Outbreaks and emergencies updates
Listeriosis outbreak in South Africa
WHO supports 16 African countries to protect against Listeriosis