You might say the source of South Africa’s deadly Listeria outbreak was hiding in plain sight, but it took the deaths of 180 people before the Health Minister could collect enough evidence to name the culprits.

A cold, processed meat product made by South Africa’s biggest producer of consumer foods is the cause of the ongoing outbreak, which has a stunning 27 percent fatality rate.

Dr. Aaron Motsoaledi, South Africa’s Minister of Health, on Sunday announced the source of the outbreak was two unrelated brands of “polony” manufactured by the Tiger Brands unit of Enterprise Foods and Rainbow Chicken Limited (RCL).

The minister said the Enterprise and RCL polony products are being recalled, and he went further.

“We advise members of the public to avoid all processed meat products that are sold as ready-to-eat,” Motsoaledi said.

The risk of cross-contamination is why South Africa issued the broader public warning.

“While we know that polony is definitely implicated, there is a risk of cross-contamination of other ready-to-eat processed meat products, either at production, distribution or retail,” according to the minister’s statement.

“This is because Listeria on the exterior casing (packaging) of polony can be transferred to other products it comes into contact with, including viennas, russians, frankfurters, other sausages, and other ‘cold meat’ products that are typically not cooked before eating.”

Motsoaledi said South Africa “can now conclude scientifically that the source of the present outbreak is the Enterprise Food production facility located in Polokwane.”

Ironically, Polokwane means “Place of Safety.” The city is the capital of South Africa’s Limpopo province. Enterprise’s production plant in Polokwane returned at least 16 samples that tested positive for the Listeria monocytogenes outbreak strain known as ST6. Preliminary results on samples from other Enterprise plants also show Listeria contamination, but the strains have not been confirmed.

South Africa’s National Consumer Commission ordered Enterprise to recall all of its polony, smoked russians, frankfurters, and Rainbow brand chicken products. Enterprise says it is cooperating fully.

Meanwhile, RCL says it is suspending all production of its Rainbow polony brand. An RCL production facility is under investigation in the Listeria probe.

After the health minister’s announcement, many South African supermarkets moved immediately to remove any suspect ready-to-eat meats from their coolers.

“In our constant search for the source of the outbreak and the treatment of people who are affected, a team from NICD (National Institute for Communicable Diseases) has interviewed 109 ill people to obtain details about foods they had eaten in the month before falling ill,” Motsoaledi said Sunday. It can take up to 70 days after exposure for listeriosis symptoms to develop.

Of the victims who have been interviewed, 93 of them, representing 85 percent, remember eating ready-to-eat (RTE) processed meat products. Polony was the most commonly named processed meat product, followed by Vienna/sausages and other “cold meats.”

South Africa began investigating the outbreak on Jan. 12 after a pediatrician treating nine children younger than 5 at Chris Hani Baragwanath Hospital suspected a foodborne disease was involved, including listeriosis.

By Jan. 27, NICD had found the same Listeria monocytogenes ST6 strain in Enterprise and RCL products as had been found in stool samples from the ill children. Motsoaledi said it was at that stage of the investigation that officials decided to “visit all food-processing sites, food-packaging sites as well as food production sites where possible.”

The health minister said preliminary results show several ready-to-eat processed meat products from the Enterprise facility located in Germiston contain Listeria monocytogenes, but the sequence type isn’t yet known.

At the RCL Wolwehoek production facility, polony products tested positive for Listeria monocytogenes, but not ST6. “However, such contamination of ready-to-eat processed meat products constitutes a health risk,” said Motsoaledi.

Sunday’s public health warning and the ready-to-eat meat recalls will likely begin to contain the outbreak, but only time will tell how quickly that occurs. Lucia Anelich, a microbiologist and prominent South African food safety expert, said it is the worst foodborne outbreak “in global history.”

As of March 2, South Africa’s count of laboratory-confirmed Listeria infections since January 2017 stood at 948. A total of 659 patients involve the outbreak strain, and 180 of those died, constituting a 27 percent fatality rate.

Except for the much higher numbers, South Africa’s listeria outbreak is eerily similar to Canada’s experience in 2008. That listeriosis outbreak caused 22 deaths of mostly elderly Canadians. It involved one of Canada’s most prominent and respected food companies, Maple Leaf Foods of Toronto accepted responsibility. The fatality rate was 40 percent.

Maple Leaf found mechanical meat slicers at its ready-to-eat meat plant spread the bacteria across Canada. The problem was a design flaw that inhibited thorough cleaning.

That outbreak also led to Canada accepting 57 food safety recommendations from food safety expert Sheila Weatherill, who conducted an independent investigation. Maple Leaf CEO Michael McCain praised the Weatherill report as exceptionally thorough and comprehensive.

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