Listeriosis is a preventable disease caused by Listeria monocytogenes bacteria that is typically transferred through contaminated food and is readily treatable with antibiotics. A total of 557 cases have been confirmed so far, according to health minister Aaron Motsoaledi.
"The bacteria is widely distributed in nature and can be found in soil, water and vegetation," he told a media briefing in Pretoria.
"From these sources, the following foodstuffs can be contaminated and cause the disease: meat and all animal products, fruits and vegetables."
People with compromised immune systems, like some of those living with AIDS and pregnant women, are also at a heightened risk, according to the World Health Organization.
In a tweeted factsheet, the health ministry urged South Africans to use safe water supplies, ensure frequent hand- washing and separate raw and cooked food.