SA's listeriosis outbreak documented in prestigious medical journal

14 February 2020 - 12:56
By Wendy Knowler, wendy knowler AND Wendy Knowler
The science paper states that “whole genome sequencing” technology has overwhelmingly proved that the source of the listeriosis outbreak was polony produced by Tiger Brands’ Enterprise factory in Polokwane.
Image: 123rf/ John Mcnamara The science paper states that “whole genome sequencing” technology has overwhelmingly proved that the source of the listeriosis outbreak was polony produced by Tiger Brands’ Enterprise factory in Polokwane.

SA’s tragic listeriosis outbreak — the world’s biggest — has been meticulously documented in an article published this week in the prestigious New England Journal of Medicine.

Authored by 31 scientists, health professionals and academics, including nine employees of the Centre for Enteric Diseases in the National Institute of Communicable Diseases (NICD), the article reveals how “whole genome sequencing” technology overwhelmingly proved that the source of the outbreak was polony produced by Tiger Brands’ Enterprise factory in Polokwane, Limpopo.

The authors, led by Dr Juno Thomas of the NICD, don’t name the source in the article, referring to the Polokwane plant as “the production facility”.

Samples taken from nine children at a Soweto creche who fell ill and were rushed to hospital in mid-January, after eating polony, identified a specific strain of listeria monocytogenes ST6, which was subsequently found in polony in the creche’s fridge, sealed polony loaves at the Polokwane plant, and in environmental samples taken in the plant.

The authors thanked paediatrician Dr Preeteeben Vallabh at Chris Hani Baragwanath Academic Hospital “for her recognition of the nursery outbreak” when the children were admitted.

In December 2018, the Johannesburg high court granted an order certifying a class action against Tiger Brands, which will determine whether the company is liable for the outbreak.

The legal case relies on the fact that the outbreak strain of listeria monocytogenes, which infected 91% of the people who died‚ was found at the Enterprise factory in Polokwane.

The class action is being brought by Richard Spoor Inc Attorneys and LHL Attorneys Inc, with US-based firm Marler Clark as a consultant to the attorneys, on behalf of those sickened by listeria-tainted polony and the families of those who lost their loved ones.

Three days after the class action was granted, Tiger Brands announced that its Polokwane plant had been given the green light by health authorities to reopen, stressing: “No liability has been established against the company for the listeriosis outbreak.”

“The legal process of the class action must still take its course.”

Personal injury lawyer and expert on food-borne illness litigation, Bill Marler of Marler Clark, who is giving the class action lawyers financial and legal support, told TimesLIVE that contacting the victims has proved to be extremely difficult.

“Only about 400 of the affected people — less than half — have come forward so far,” Marler said.

That’s despite an intensive advertising campaign paid for by Tiger Brands, and Marler, on behalf of the class action attorneys.

“That leaves a lot of people who are quite ill, or family members of those who died, without the means of being fairly treated,” Marler said.

A neutral, court-appointed company has been tasked with identifying and contacting the victims on behalf of the NICD.

Marler said the level of detail that the NICD and the World Health Organisation had produced to link the illness with the Tiger Brands product was “more overwhelming than any food-borne disease case I’ve been involved with in 27 years”.

The unique features of SA’s listeriosis outbreak, according to the article’s authors, is that it happened “in a middle-income country with a high prevalence of HIV infection and a high fertility rate”.

Of the 937 cases identified, half were associated with pregnancy.

Listeriosis is the most deadly food-borne disease, with 20-30% of victims dying from it.

The article notes that the number of cases decreased “dramatically” after the recall of the implicated Tiger Brands products on March 4 2018.

“By mid-April 2018 — 6 weeks after recall — fewer than 5 cases were reported weekly.”

At the height of the outbreak in mid-November 2017, case numbers peaked at 41 per week.

The article concludes by stressing the crucial role played by whole genome sequencing in detecting and investigating food-borne disease outbreaks.

“As the global shift to whole-genome sequence typing for food-borne pathogen surveillance accelerates, developing countries should build the capacity to leverage this technology in a rapidly evolving landscape of food-safety concerns,” it says.

“And targeted health communication for the prevention of listeriosis among pregnant girls and women and HIV-infected persons in developing countries may help mitigate the risk of disease in these vulnerable groups.”

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