Listeriosis outbreak: What you need to know

Photo: Foodessence

What is Listeriosis?

It’s basically food poisoning, caused by the Listeria bacterium, most commonly found in certain high-risk foods, but also other sources in nature.

“It’s found in water, soil, infected animals, human and animal faeces, raw and treated sewage, certain vegetables, effluent from poultry and meat processing facilities, decaying corn and soybeans, improperly fermented silage, and raw or unpasteurised milk,” says Gareth-Lloyd Jones, chief commercial officer at Ecowize.

There is no vaccine, only treatment with antibiotics if diagnosed in time.

The health minister, Aaron Motsoaledi, noted that most of the cases of Listeria infection have been reported in Gauteng, followed by the Western Cape and KwaZulu-Natal.

With at least 66% of the infections recorded in public hospitals, and 34% in private health facilities, Jones suggests that the source is likely to be a food product consumed by South Africans from all socio-economic groups.

Symptoms

Listeriosis presents with flu-like symptoms - fever, muscle aches, and sometimes nausea or diarrhoea. If infection spreads to the nervous system, symptoms include headache, stiff neck, confusion, loss of balance, or convulsions.

High-risk foods

“Foods which are most commonly identified as high-risk for Listeria infection range from improperly pasteurised dairy products such as milk, cheese and ice cream, to raw vegetables, poultry, fermented raw-meat sausages, and cooked or ‘ready-to-eat’ deli meats,” Jones adds.

A research study by the Listeria Study Group notes that Listeria monocytogenes grew from at least one food specimen in the refrigerators of 64% of individuals with a confirmed Listeria infection (79 of 123 patients). In addition, 33% of these refrigerators (26 of 79) were also found to contain foods that grew the same strain of Listeria with which the individual had been infected - a frequency much higher than would be expected simply by chance.

While anyone can be infected by the disease, certain groups are at higher risk. This includes:

• newborns;
• the elderly;
• pregnant women and their unborn babies; and
• immune-compromised individuals with HIV, diabetes, cancer and chronic liver or kidney disease.

Precautions

• Wash your hands more regularly when handling food;
• Ensure that food is cooked thoroughly;
• Only use pasteurised dairy products; and
• store food at safe temperatures.

“It is essential that South Africans become more aware of the risks associated with food contamination and that they practice caution when handling food products, not only during times of disease outbreaks such as this, but in their everyday lives,” Jones concludes.