Complete information is only available for 689 of the people with confirmed infections. Of those, 191 have died, for a mortality rate of 28 percent, according to the South Africa Centre for Enteric Diseases and Division of Public Health Surveillance and Response.
As reconfirmed earlier this week by the National Institute for Communicable Diseases, the outbreak update posted Friday reported the source of the outbreak is ready-to-eat processed meat that is called polony and is similar in appearance and packaging to baloney.
The government has named Enterprise Foods' polony as the source of the outbreak, based on DNA fingerprinting of Listeria samples from sick people and unopened packages of Enterprise polony. Enterprise is a wholly-owned subsidiary of the mega-food company Tiger Brands. It's products were recalled March 4.
“… it is expected that new outbreak-related cases will continue to be reported,” according to the Friday outbreak update. “The number of laboratory-confirmed cases per week are declining since the recall.”
Those additional cases are likely, the federal health agency said, for the following reasons:
The incubation period of listeriosis can be up to 70 days;
The implicated food products have a long refrigeration shelf life, and it is possible that despite the recall some products were not removed from retail/home settings and consumption might occur; and
The possibility of cross-contamination of other types of foods in retail or home settings.
The public health officials in South Africa reported that out of 547 clinical Listeria monocytogenes isolates that have undergone whole genome sequencing, 92 percent match the Listeria monocytogenes sequence type 6 （ST6）， which is the outbreak strain.
