Tracing the source of the listeriosis outbreak is like finding a needle in a haystack, but also having to search for the haystack itself, Health Minister Aaron Motsoaledi said.
Briefing the media in Pretoria on Monday, Motsoaledi said the source of the outbreak, which has already claimed the lives of 61 people since January 2017, was proving to be extremely difficult to find.
Listeriosis is a bacterium disease found in soil, water and vegetation, which contaminates food sources, such as animal products and fresh produce.
“It’s like searching for a needle in a haystack and the problem is that we are still looking for the haystack before we start searching for the needle, we don’t even know yet which haystack it is, that’s how difficult this thing is,” Motsoaledi said.
The National Institute of Communicable Diseases (NICD) has identified the specific strain of listeriosis using Genome Sequencing Analysis, which used isolates from the blood of infected patients, food samples and food production isolates.
Of the clinical isolates taken from patients’ blood, 91% are sequence type six, which represents a single strain of listeria, explained Motsoaledi.
Link to food source unknown
Despite the strain being identified, it has not yet been linked to any food or a specific food production site.
Since Motsoaledi’s announcement of the outbreak on December 5, 2017, a total of 170 extra laboratory-confirmed cases of listeriosis have been reported, bringing the total number of confirmed cases to 727.
The minister said, of the 170 confirmed cases, 119 occurred between December 5, 2017 and January 5, 2018.
Only five patients have been traced in the 119 new cases, of which three had died.
The death toll has also risen since December 5, 2017, from 36 confirmed deaths to 61, as more patients are traced.