The country's health department confirmed the outbreak at a press conference on Tuesday stating that the majority of the 557 laboratory-confirmed listeriosis cases were coming from the Gauteng province.
South Africa is battling an outbreak of a bacterium disease which has killed 36 people across the country out of the over 500 cases recorded last month.
Health Minister Aaron Motsoaledi says they've launched an investigation into the source of the listeriosis outbreak in South Africa.
"The bacteria is widely distributed in nature and can be found in soil‚ water and vegetation".
He said the bacteria was not new, as it occurs every year and is seen in hospitals with only 60 to 80 cases detected and treated each year.
It poses a higher risk for newborns, the elderly, pregnant women, and persons with weak immunity, the health department said.
"The source of this outbreak is now being investigated, and all the stakeholders are cooperating with the investigation led by the NICD (National Institute for Communicale Diseases)", he said.
Motsoaledi reiterates listeriosis is treatable and preventable.
"From these sources, the following foodstuffs can be contaminated and cause the disease: meat and all animal products, fruits and vegetables".
"This triggered a review of all cases diagnosed in both public and private hospitals", he said.
He said infection with listeria may result in conditions including flu-like illness with diarrhoea, including fever, general body pains, vomiting and weakness, infection of the bloodstream which is called septicaemia, and meningoencephalitis [infection of the brain]. It can be treated with an antibiotic called ampicillin.