Listeriosis: what you need to know
One in four people who get listeriosis dies, but while it’s serious it can be treated and prevented. Here’s what you need to know about this food-borne disease
SHE’S still struggling to come to terms with what happened. How is it possible that her child could be dead? More than anything else Tanya Clack wants answers. In August last year her daughter Sonette was looking forward to starting a new chapter as she married a man she adored. But four months later she lay comatose in hospital.
On 1 December Sonette (34) was admitted to Steve Biko Academic Hospital in Pretoria with suspected meningitis. But a week later as she lay unconscious, tests revealed she actually had listeriosis, a food-borne disease. Tanya felt relieved – at last doctors knew what was wrong with Sonette and could start treating her.
She was delighted when a day later her daughter opened her eyes. But within moments her joy turned to horror.
“She regained consciousness and the next minute she was dead,” says Tanya, who’s now looking after Sonette’s two children, aged 10 and 16, from a previous relationship.
The Clacks aren’t the only family struggling to come to terms with losing a loved one to a disease that until now had never been on their radar. With more than 60 deaths and almost 750 confirmed cases countrywide, South Africa is in the grip of what the World Health Organisation (WHO) has officially declared the worst outbreak of listeriosis in recorded history.
It’s far more than just a nasty stomach bug – for those unlucky enough to contract it, the disease is potentially fatal. Around 25% of those who get it die, which makes it more dangerous than typhoid fever or even bubonic plague.
While each week brings news of further casualties experts are lost for answers – they simply have no idea which food is harbouring the disease that’s affecting rich and poor, young and old.
The health department suspects the outbreak is being caused by the contamination of food from farms or foodprocessing plants but because it can take up to 70 days for symptoms of the disease to show it makes isolating possible culprits difficult.
In a media briefing earlier this month health minister Aaron Motsoaledi didn’t mince his words. He acknowledged that the search for the contaminated food is far more complex than looking for a needle in a haystack. “The problem is we’re 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,” he said.
But what is this disease and how do you avoid contracting it? Here’s everything you need to know.
WHAT IS LISTERIOSIS?
It’s a bacterial disease that originates in soil, water or vegetation which contaminates food sources such as animal products and fresh produce, explains Dr Lucia Anelich, a microbiologist and food safety expert.
Foods most often affected include deli meats and Vienna sausages, refrigerated pâtés and meat spreads, unpasteurised milk and dairy products‚ smoked seafood‚ ready-made meals, raw sprouts and fresh and frozen fruit and veg.
The disease, which is caused by the bacterium Listeria monocytogenes, occurs worldwide and initially results in flu-like symptoms. It was first documented in South Africa in 1977 in Johannesburg and since then there’ve been sporadic outbreaks. But nothing on the scale of what we’re seeing now.
Late last year after doctors at Steve Biko Academic and Chris Hani Baragwanath hospitals in Gauteng noticed an increase in the number of cases they started monitoring the situation closely.
“We were seeing cases predominantly from Gauteng and then the Western Cape and KwaZulu-Natal, followed by all the other provinces,” says Dr Juno Thomas, who heads the National Institute of Communicable Diseases’ (NICD) Centre for Enteric Diseases.
Using genome sequencing analysis to test the blood of infected patients the NICD established that they were all infected with the same strain of listeriosis (the ST6 strain). This has helped confirm suspicions that the outbreak is linked to one contaminated food source that’s widely distributed and consumed by people across all socio-economic groups.
With Gauteng reporting the most cases ( followed by the Western Cape and KwaZulu-Natal) there’s a possibility the infected product might come from there or it could simply be that more people from that province are seeking medical attention, Dr Anelich says.
A chicken abattoir in Tshwane was closed after samples showed evidence of listeria but further testing revealed it wasn’t the ST6 strain. It’s since reopened after meeting certain conditions put in place by the department of health to prevent the spread of the disease.
With the abattoir cleared as the source of the current listeriosis outbreak, officials are back at the drawing board. And while the hunt for the source continues, health workers are bracing themselves for more casualties. At the time of going to print, 67 people had died of the disease while 748 cases had been reported countrywide.
“We expect the number of deaths to go up because we know listeriosis has a mortality rate of at least 20 to 30%,” Dr Thomas says. S