The listeriosis death toll has risen to 61 since the outbreak was announced in early December last year, Health Minister Dr Aaron Motsoaledi said on Monday.
Motsoaledi also said genome sequencing was being carried out to shed light on the source of the outbreak.
Gauteng still has the most cases of listeriosis, with 442 out of the 727 confirmed cases. The Western Cape was second with 92 confirmed cases.
The Department of Health has amended the list of notifiable diseases to now include listeriosis. Prior to this outbreak, it was not on the list
Listeriosis is a bacterium found in soil, water and vegetation, which contaminates food sources, such as animal products and fresh produce.
Motsoaledi has urged anyone who experiences symptoms of listeriosis to seek medical attention immediately.
He said the disease can cause meningitis, which is an infection of the brain, and septicaemia, which is an infection of the blood steam. Both can be fatal.
However, he stressed that, while the disease was serious and dangerous, it was treatable with antibiotics.
"If you encounter the symptoms I've mentioned please rush to look for medical help. In other words, don't just assume and sit at home, especially if you get flu-like symptoms now in summer."
Motsoaledi added that, while anyone can contract the disease, which has a mortality rate of between 20 and 30 percent, those who have a high risk of developing listeriosis are newborns, the elderly, pregnant women and people with weak immunity systems, as a result of HIV or cancer.
In December, a Gauteng abattoir had been prohibited from selling meat after samples taken from there tested positive for the listeria pathogen, the Gauteng health department said.
In a statement, Gauteng Health MEC Dr Gwen Ramokgopa said the abattoir in the Tshwane area was tested after the food sample of a listeriosis patient was traced there.
"Based on the discovery, the prohibition notice has been issued to the abattoir in terms of Regulation 4 (3) of regulations governing the general hygiene for food premises and the transport of food, for preparing food to the identified abattoir," Ramokgopa said.
"They're obliged to comply until the following has been adhered to:identification of the source of contamination;disinfection of the premises; [and]surface swabs and water samples taken before and after disinfection."