The victims include newborns, the elderly and people with weakened immune systems: the most vulnerable in society. Hardly a laughing matter.
The outbreak has been linked so far to two major producers: Rainbow Chicken and Enterprise products (ranging from polony to the “luxury” wafer-thin hams sold by Woolies), which raises questions about food safety, who is policing it, and the quality of food consumed by millions of South Africans - mostly from poorer communities.
By now we know Listeria is the bacterium that causes listeriosis, a disease that can have severe consequences for pregnant women, children, the elderly and immuno-compromised people.
Diabetics, asthmatics, people with cirrhosis (a liver disease), ulcerative colitis (inflammatory bowel disease) and cancer are also at risk.
Last week, reports indicated four people had died from eating “spanspek” or rock melon in Australia. Melons also killed 31 in the US in 2011.
Food Standards Australia New Zealand reports that in 1997, 1 566 people took ill in Italy after eating corn and tuna salad, possibly caused by cross-contamination from untreated foods.
In 1981, 41 people got sick and 18 died in Canada after eating coleslaw. The outbreak was traced to cabbage fertilised with listeria-contaminated sheep manure.
In 2008, 22 elderly people in Canadian retirement homes died after consuming contaminated deli meats.
Most foods implicated in listeriosis are ready-to-eat (RTE), such as deli meats, pâtés/meat spreads, unpasteurised milk and soft cheeses, smoked seafood, pre-packaged salads and raw sprouts.
Yet the outrage and panic, fuelled by the Health Department’s advice to steer clear of all deli meat, needs to be placed in context: listeria is destroyed by temperatures over 70ºC, at steaming point.
But it is not destroyed by refrigeration or freezing, and if contaminated products come into contact with other foods, it spreads.
It’s not the first such outbreak and judging by uneven standards in the food sector and insufficient policing, it won’t be the last.
Listeria might be in the spotlight now, but food-borne outbreaks caused by E coli and salmonella, which are notifiable, are frequent occurrences in South Africa, says food safety expert Linda Jackson.
What makes this more alarming is that the death rate from listeriosis is comparatively high - almost 30% - compared with salmonella and E coli, which have mortality rates of less than 1%.
“Listeria is the new kid on the block now, but Statistics South Africa’s annual stats indicate deaths from other food-borne outbreaks, caused by salmonella and E coli. People need to ask more questions about that.
“Listeria is naturally occurring in agriculture, but the question comes around our processes - once products are processed, we need to ensure there isn’t any listeria and ensure there’s no recontamination.”
Regulations are in place which all food establishments and manufacturers are compelled to commit to.
“Facilities are and should be designed to ensure there are physical divisions in the factory to prevent cross-contamination. There are specific hygiene requirements and strict protocols in place,” she says.
But the rules for the food industry aren’t complied with as they should be.
Jackson says the big brands supplying retailers are subject to third-party audits to monitor their standards, in addition to the legal requirements.
“Retailers took matters in hand 10 years ago - they don’t rely on local health authorities and charge suppliers for those audits.”
Smaller retailers, though, have more latitude. Privately-owned retailers don’t necessarily apply the same standards as bigger outlets, so that “artisanal” delicacy on the shelf might well have been produced in someone’s filthy kitchen or garage.
“If I go into any restaurant, I must see a certificate of acceptability. You have to have a licence to trade; the environmental health inspectors are supposed to inspect and issue certificates as part of their monitoring.
"But there are many people trading without certificates and even if they have certificates, there aren’t enough inspectors to check.”
In an ideal world, health inspectors would be monitoring every food truck, roadside stand, market, café and home industry, but authorities have limited resources.
“The Department of Health works on a risk-based approach - where are the most people fed? - then they allocate resources where the highest risk is, because of the volume of people.
“If they don’t know about you, they don’t check,” Jackson says.
Food safety is a shared responsibility, though, and anyone preparing food must practise good hygiene standards.
An EU study has suggested up to a third of European listeriosis cases are caused in people’s homes.
“How many of us use colour-coded cutting boards? Restaurants should use those so you know you’re not chopping raw fish on a salad board, but we haven’t educated consumers sufficiently about food safety.”
And how many of us read instructions properly on the label? Jackson says best before, use by, storage and serving instructions are messages from the food industry which shouldn’t be ignored.
“If nothing else, the consumer is so outraged because we have been blindly trusting the food industry.
"It’s like finding out your husband has been cheating. You want to kick yourself for being so trusting.
“From the food industry’s perspective, that trust is fragile and it now needs to be rebuilt.”