SA listeria cases rising but NICD cautions on the numbers

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SA‘s National Institute Communicable Diseases (NICD) warns that because of ‘recent challenges’ in state laboratory information system data and a ‘public holiday lag’, its listeria outbreak statistics were likely to change on a daily basis and ‘trends must be interpreted with caution’.

Another 31 cases of listeriosis have been confirmed with six more deaths‚ bringing the total number since the beginning of last year to 748 and deaths to 67‚ the National Institute Communicable Diseases (NICD) revealed on Friday of last week. About 40% of those who have died were babies less than four weeks old.

The NICD has warned that because of “recent challenges” in state laboratory information system data since mid-November “and a possible lag in reporting as a result of the public holidays,” case numbers for the last six weeks of 2017 were likely to change on a daily basis “and trends must be interpreted with caution”.

The report says the NICD reported that “final data” was only available for 21% of the 748 confirmed cases of listeriosis‚ of which 42% had died. Listeriosis’s average mortality rate is between 20% and 25%. Those with confirmed listeriosis were patients in state and private hospitals – roughly two thirds in state hospitals (65%) and a third (35%) in private hospitals.

The report says the NICD has established via genome sequencing that in most cases‚ the listeria came from a single source‚ thought to be a particular product or range of products. Pretoria-based microbiologist and food safety expert Dr Lucia Anelich said the “culprit” was most likely a product that is eaten by consumers across the country and “extremely often”.

Listeriosis symptoms develop any time between two and 30 days after eating food contaminated with the listeria pathogen. In pregnant women they include mild flu-like symptoms‚ headaches‚ muscle aches‚ fever‚ nausea and vomiting‚ and if the infection spreads to the nervous system it can cause stiff neck‚ disorientation‚ or convulsions.
High on the list of foods known to have caused other listeriosis outbreaks are ready-to-eat foods which consumers don’t cook or heat before eating‚ primarily deli meats – slices of ham‚ polony‚ cooked chicken and the like.

“Deli meats are obviously consumed by a wide variety of people in the population‚ whether it’s a cheaper cut or a more expensive one‚” Anelich says. “But other products might also be just as implicated‚ and it’s really difficult to point a finger in a specific direction‚ considering we have absolutely no other leads at this stage.”


“Listeriosis is a real challenge to health services because it involves so many sectors – not only health services, but the food industry as well as agriculture and farming,” the World Health Organisation (WHO) media officer Christian Lindmeier is quoted in an IoL report as saying. The WHO said the disease occurrence is relatively low and an investigation into the source of the outbreak is ongoing.

However, the report says, listeria’s severe and sometimes fatal health consequences, particularly among infants, children and the elderly, count it among the most serious of foodborne infections.

Lindmeier noted that the people who are becoming infected are from a diverse socio-economic background with both private and public hospitals reporting cases.

“South Africa has implemented some very important measures such as making listeriosis a notifiable disease for the first time ever,” said Lindmeier. “This means that when a clinic gets a case of listeriosis, they must notify the government. This is helping to track the disease.”

The report says a complication in fighting the disease is that it takes about three weeks between when a person eats or drinks contaminated food or drinks and when they actually become sick. Due to this long incubation period, it’s hard to identify the food source, said WHO. “Even if a food source is identified, we can expect to have cases reported for several weeks to come,” said Lindmeier. “This is making the investigation into the source of the outbreak particularly complex.”


Gauteng is the epicentre of the listeriosis outbreak but poor record-keeping at hospitals and clinics is hindering prevention and treatment because many of those infected cannot be contacted or traced, writes Jack Bloom, the Democratic Alliance’s Gauteng Shadow Health MEC on the Politicsweb site.

Bloom writes: “According to Health Minister Aaron Motsoaledi, the number of listeriosis confirmed by lab testing has increased from 557 in early December to 727 cases, of which 443 (61%) are from Gauteng. But only 134 of these confirmed cases have been traced, which highlights the problem that patients often cannot be traced because their contact details have not been accurately recorded in hospitals and clinics. Another problem is that false addresses are sometimes given, particularly by foreign patients.

“Although the outbreak is across all nine provinces, clinical tests have revealed that the listeria originates from a single source which is most likely a food product produced in Gauteng.

“The listeriosis mortality rate is 20%-25%, and food scientists say that this is the worst recorded outbreak in global history. The real number of deaths due to listeriosis is probably much higher than the 61 deaths officially recorded because so many patients could not be found subsequent to their positive diagnosis in a laboratory.

“These patients need to be interviewed so that environmental inspectors in the local municipalities have information as to where the bacteria is coming from, otherwise it is like searching for a needle in a haystack.

“I welcome the designation of listeriosis as a notifiable disease, but urgent attention must be paid to the recording of patient contact details particularly in Gauteng so that we can speedily find the source of the outbreak that is causing more and more deaths.”


The Ghanaian Ministry of Health has issued a public health alert on listeriosis following the outbreak of the disease in South Africa, reports Eyewitness News. While South African authorities try to get to the source of the countrywide outbreak, health officials in Ghana are trying to prevent it from spreading to the West African nation.

According to the report, the Ghanaian Ministry of Health says it has noted with concern the outbreak of listeriosis in South Africa. The department says it will be stepping up its surveillance of products being imported from there, including meat, dairy products, as well as fruit and vegetables.

It has further urged the public to remain calm as they continue to monitor, investigate and assess the quality of plant and animal products coming from South Africa.

The Times report
IoL report
UN material
Politicsweb report
Eyewitness News report

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