Updated 12 March 2018

UPDATE: Listeriosis death toll rises to 60

The number of dangerous Listeria cases in South Africa has been revised, with the food-borne disease now a category 1 notifiable medical condition.

South Africa has experienced its biggest Listeriosis outbreak ever, with the food-borne disease claiming 60 lives after infecting 647 people this year.

The deadly food-borne disease, which was first documented in the country 40 years ago, has now been classified as a category 1 notifiable medical condition, the National Institute for Communicable Diseases (NICD) has confirmed.

READ: What you should know about the deadly Listeriosis outbreak

"This means it must be reported immediately using the most rapid means upon clinical or laboratory diagnosis followed by a written or electronic notification within 24 hours of diagnosis," the institute explained.

"This will allow us to investigate possible exposures for disease sooner," the NICD told Health24.

No need to panic

The NICD added that South Africans should not panic and reiterated that everyone should adhere to the five keys to safe food.

"These are food hygiene practices that assist in the prevention of foodborne illness generally, not just Listeria."

It is also advised to cook food thoroughly, only use pasteurised milk products and keep food at safe temperatures.

The data suggests most cases in this outbreak have had exposure to a widely available, common food type or source. However, it is not clear what the source of the infection is.

Increase in number of cases

The total number of laboratory-confirmed Listeriosis cases is now 647 compared to 557 when it was first announced by the Minister of Health Aaron Motsoaledi earlier in December. The initial death count was 36.

Gauteng is still the province most affected with 399 cases, followed by Western Cape at 84 and 45 in KwaZulu-Natal.

Where age and gender was recorded, it ranged from birth to 93 years, and females account for 55% of cases.

Dr Lehlohonolo Majake-Mogoba, a GP and public health specialist, told Health24 most people will present with gastro and cramps, which can be treated with antibiotics.

"People with normal immune systems rarely develop invasive infection."

She said listeria complications are caused by severe infection progression especially for people with compromised immune systems such as the elderly, pregnant women and people with diabetes, cancer and HIV.

If infection spreads to the nervous system symptoms such as headaches, stiff neck, confusion, loss of balance, or convulsions can occur.

"The infection enters the intestines and can then go into different parts of the body like joints causing arthritis and the brain leading to meningitis," Dr Majake-Mogoba explained.

She warned that meningitis may result in seizures and can cause death if not successfully treated.

Dr Majake-Mogoba urged people to be careful where they buy their ready to eat foods during the busy festive period.

A probe with a team consisting of public and private entities into the outbreak is ongoing.

Image credit: iStock