Johannesburg - The source of the current Listeriosis outbreak is the Enterprise food facility located in Polokwane, Health Minister Aaron Motsoaledi confirmed on Sunday.

Motsoaledi held an urgent media briefing at the National Institute of Communicable Diseases after the source was confirmed in the early hours of Sunday. 

He was accompanied by scientists who have been working to identify the source of the outbreak.

"In our constant search for the source of the outbreak and the treatment of people who are affected, a team from the 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. Ninety-three (85 percent) reported eating ready to eat (RTE) processed meat products, of which polony was the most common, followed by viennas/sausages, and then other ‘cold meats’," Motsoaledi said.

On Friday, January 12, nine children under the age of five presented to Chris Hani Baragwanath Hospital with febrile gastro-enteritis. The paediatrician suspected foodborne disease, including listeriosis, as a possible cause. 

The environmental health practitioners (EHPs) were informed and on the same day visited the crèche and obtained samples from two unrelated polony brands (manufactured by Enterprise and Rainbow Chicken Limited (RCL) respectively) and submitted these to the laboratory for testing.

"Listeria monocytogenes was isolated from stool collected from one of the ill children, and from both of the polony specimens collected from the crèche. These isolates were sent to the NICD Centre for Enteric Diseases and underwent whole genome sequencing and genomic analysis. The ST6 sequence type was confirmed on all three isolates on Saturday 27th January," he said.

Following the lead from the tests performed on the children from Soweto and the food they had ingested, the EHPs, together with the NICD and agriculture, forestry, and fisheries department (DAFF) representatives, accompanied by three technical advisors from the World Health Organisation (WHO) in Geneva, visited a food-production site in Polokwane and conducted an extensive food product and environmental sampling.

"Listeria monocytogenes was isolated from over 30 percent of the environmental samples collected from this site, which happens to be the Enterprise factory in Polokwane. To conclude the investigation, whole genome sequencing analysis was performed from this Enterprise factory and the results became available midnight or last night (Saturday]. The outbreak strain, ST6, was confirmed in at least 16 environmental samples collected from this Enterprise facility.
"The conclusion from this is that the source of the present outbreak can be confirmed to be the Enterprise food production facility in Polokwane," Motsoaledi said.

He also revealed that preliminary tests showed that several ready to eat products at enterprise's Germiston factory also contain listeria, but the sequence was not yet known.

Furthermore, the minister revealed that, as of March 2, the total number of laboratory-confirmed listeriosis cases had risen to 948 since January 2017. 

Of the 948, a total of 659 patients had been traced and 180 of them had died - a 27 percent fatality rate, he told journalists.