NICD refutes DA claims on listeriosis source; death toll still rising

Organisation: Position: Deadline Date: Location:

MotsoalediThe National Institute for Communicable Diseases (NICD) expressed ‘major concern’ over Democratic Alliance claims that the primary source of the outbreak was still unknown and that the Minister of Health Dr Aaron Motsoaledi had backed down on an earlier announcement that the source had been identified. Meanwhile, the death toll continues to rise, with six more deaths last week taking the tally to 189.

Reacting to the claim made last week by the Democratic Alliance’s (DA’s) Shadow Health Minister Patricia Komape, that the source of the listeriosis outbreak has still not been found, the NICD has issued a statement, which reads:

“The National Institute for Communicable Diseases (NICD) is concerned about recent developments and statements supposedly released as facts into the public domain about the listeriosis outbreak. We are particularly worried about the confusion that emanated from statements made at the meeting called by the Parliamentary Portfolio Committee on Agriculture on 28 March 2018.

“Of major concern are the claims that the primary source of the outbreak is still unknown, and that the Minister of Health has backed down on his previous announcement that the source had been identified, both of which we refute. The statements the Minister of Health has made have emanated from epidemiologic and scientific investigations conducted by the NICD. The implication that the NICD has misled the Minister of Health and the public is rejected. Furthermore, we condemn the statement made that the government prematurely scapegoated ‘Enterprise and Rainbow’ without sufficient evidence. We contend that this evidence has been amply provided by the NICD.*

“We do not regard these claims as a small matter, because the NICD is not just a routine diagnostic laboratory with an impact localised to South Africa. The NICD’s work goes far beyond the borders of our country and has an international impact. In outbreaks of this nature, the NICD is obligated by the International Health Regulations to report findings through the National Department of Health to the World Health Organisation (WHO), and cannot afford to, and does not mislead.

“To serve its purpose, the NICD has specialised laboratories and public health and epidemiologic expertise. This expertise leads it to serve as a reference centre, not only for the public and private sectors in South Africa, but across Africa. It shares information and works together with the WHO and eminent international institutions (including the Centres for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) of the US, the European Centre for Disease Control (ECDC) and Public Health England). The NICD is the co-ordinator of the prestigious PulseNet Africa network, within PulseNet International. PulseNet is a global network of laboratories dedicated to tracking foodborne infections (including listeriosis) world-wide, all of whose laboratories, including the NICD, utilise internationally-recognised standardised genotyping methods and share information in real-time.

“Therefore, the work of the NICD is scientifically sound and evidence-based. For those who still have lingering doubts, this is how we arrived at the conclusions announced by the Minister of Health on 04 March 2018.

“The search for the cause of the outbreak began with the isolates of Listeria monocytogenes bacteria from case-patients referred from National Health Laboratory Service (NHLS) and private sector clinical laboratories to the NICD, where they underwent confirmatory testing and whole genome sequencing (WGS). WGS is the most sensitive and specific molecular tool available to assess genetic relatedness of bacterial isolates. Of the 439 clinical isolates from case-patients sequenced to date, 92% belong to sequence type 6 (ST6) and are highly genetically related. This confirms that this single strain is causing the outbreak and is responsible for disease in the vast majority of patients with listeriosis.

“At the same time, an intensive process of trying to identify the source of the outbreak was undertaken by the Departments of Health (DoH), Agriculture, Forestry and Fisheries (DAFF) and Trade and Industry (DTI), municipalities and the NICD. Epidemiological investigations included interviewing patients. As 86% of patients interviewed reported eating polony in the month before falling ill with listeriosis, ready-to-eat processed meat products became the focus of investigations. The key breakthrough came when a group of nine children attending the same crèche in Soweto developed febrile gastroenteritis in January 2018. The L. monocytogenes ST6 outbreak strain was identified in one child and in three samples of two brands of polony from the refrigerator at the crèche. This prompted further investigation of the production facilities manufacturing these polony products.

Enterprise Foods’ Polokwane production facility was visited on 2 February 2018 by a team, which included two WHO food safety experts. Extensive sampling was done. Polony production involves a number of steps: raw ingredients are mixed into an emulsion, the polony emulsion is poured into casings (the plastic wrapping) and clipped at either end of the casing, the polony is cooked in its casing, then finally it is cooled. Any Listeria that is present in the raw ingredients or emulsion should be killed during the cooking process. However, any L. monocytogenes found beyond the cooking stage poses the danger of contaminating the polony and causing disease, because polony is not usually cooked again before it is eaten. Of great concern was that the L. monocytogenes ST6 outbreak strain was found in the post-cooking processing environment, and also on the final polony products.

“The whole genome sequencing (WGS) technology that identified the ST6 outbreak strain is the gold standard method for characterising which specific L. monocytogenes strain is causing an outbreak. This highly specialised test is performed at the NICD. WGS essentially shows the genetic fingerprint of the bacteria, by sequencing the chemical building blocks (nucleotides or base pairs) that make up its genome (the complete set of its DNA, including all of its genes). The L. monocytogenes genome has approximately 3m base pairs. The outbreak strain isolates from patients and from the Enterprise Foods’ Polokwane production facility (notably, the post-cooking area and the final product clips and casing) differ by only ≤7 single base pairs out of 3m. This extremely high level of genetic relatedness (99.99% similarity) means there can be no doubt that these L. monocytogenes ST6 strains are all linked, and that there is certainty that products manufactured at Enterprise Polokwane are the source of the outbreak. This is much like paternity confirmation by DNA testing.

“From the evidence above, it is extremely misleading for anyone to claim that the primary cause of this listeriosis outbreak is unknown.

“Since the first press conference held by the Minister of Health on 05 December 2017, it has been reiterated many times that L. monocytogenes is widely found in nature and can be found in water, soil, vegetation, and the faeces of some animals. Food can be contaminated from any of these sources throughout the food chain (farm, processing, packaging, retail and home food preparation). However, normal food production safety measures and water treatment procedures should deal with the risk of contamination. In addition, the WHO’s five keys to safer food should be practiced by all. These are:
• Wash hands and surfaces before, and regularly during food preparation.
•Separate raw and cooked food, and don’t mix utensils and surfaces when preparing food
•Cook food thoroughly – all bacteria are killed above 70°C
•Keep food at safe temperatures – either simmering hot, or in the fridge
•Use safe water and safe ingredients to prepare food.

“*We can report today that additional results from samples of products produced at the Enterprise Polokwane production facility and sold at the Enterprise Germiston factory shop are available. Seven samples of ready-to-eat processed meat products taken on 15 February 2018 tested positive for L. monocytogenes ST6 (outbreak strain). This means that the outbreak strain has been found inside the ready-to-eat processed meat products manufactured at Enterprise Foods’ Polokwane production facility, dispelling claims made to the contrary.”

 

The NICD announced on Thursday of last week that the death toll in the listeriosis outbreak has climbed to 189 – up six deaths from its last update.

Business Day reports that it also announced that there were now 982 confirmed cases of the deadly disease‚ with outcomes known in 687 of these. The mortality rate is now 28%.

A nationwide recall of affected food products – which has been traced back to ready-to-eat processed meat products manufactured at Enterprise Foods’ Polokwane production facility – was announced on 4 March.

However‚ the report says, as it had previously warned there would be‚ the NICD said more new cases of listeriosis had been confirmed since the recall. In total‚ there had been 23 laboratory-confirmed cases since 4 March – but all exposures occurred prior to the recall.

The institute said that the reasons for the post-recall new cases were that: the incubation period of listeriosis can be up to 70 days; implicated food products have a long refrigeration shelf life‚ and it is possible that despite the recall some products were not removed from retail or home settings and consumption might occur; and the possibility of cross-contamination of other types of foods in the retail or home setting may result in additional cases.

“As of 26 March 2018‚ a total of 982 laboratory-confirmed listeriosis cases have been reported to NICD since 1January 2017. Most cases have been reported from Gauteng (576 cases) followed by Western Cape (121) and KwaZulu-Natal (71)‚” the NICD said in an update posted on its website.

 

NICD says that eight more listeriosis cases have been picked up in the Western Cape. Eyewitness News reports that this brings the total to 121 cases in the province since a countrywide outbreak was first reported last year.

The institute’s Juno Thomas says more cases could be detected as the incubation period for listeriosis can be up to 70 days. “Eight cases were diagnosed. Some of those still have to be followed up because treatment can take three weeks. So we get to know about the cases once the diagnosis is made.”

Twenty-nine people have died in the Cape from the food-borne disease.

 

Polony and other ready-to-eat processed meat manufacturers who have been desperately attempting to distance themselves from the Enterprise and Rainbow products recalled due to listeria contamination had been left reeling by the news that the primary source of the listeriosis outbreak remains unknown, a Sowetan report says.

The DA claimed that at a parliamentary briefing last week‚ the ministries of health‚ trade and industry‚ and agriculture‚ forestry and fisheries admitted that although traces of listeria were found at both the Enterprise and RCL’s Rainbow chicken polony facilities‚ they were not the primary sources of the outbreak. “It is now apparent that the government … has opted for prematurely scapegoating Enterprise and Rainbow because it does not have proper emergency plans in place to contain this outbreak‚” the DA said.

The report said, asked to comment‚ food safety expert Dr Lucia Anelich said she was unsure what was meant by “primary source” of the outbreak. “We know that the outbreak strain of listeria‚ ST6‚ was found in the Enterprise plant‚ but it’s true that we don’t know its origin‚” she said.

Both Health Minister Dr Aaron Motsoaledi and Thomas have been consistently warning consumers to avoid all ready-to-eat processed meats‚ including polony‚ viennas and ham “until there is further clarity as to the extent of product contamination”.

“The finding that the external casing of polony products sampled at the Enterprise Foods’ Polokwane production facility were found to be contaminated with the outbreak strain of L. monocytogenes‚ which means that there was a likelihood of cross-contamination of other RTE processed meat products when stacked together in cold storage and refrigerators at retail level‚ including products of different brands from different manufacturers‚” Thomas said.

“My understanding is that the Department of Health is currently investigating other RTE processed meat producers and retailers are also conducting their own tests on house-brand RTE processed meats to ensure safety.”

 

Parliament has reported that the Portfolio Committee on Agriculture, Forestry and Fisheries invited the Portfolio Committee on Health to received briefings from the Department of Agriculture, Forestry and Fisheries; the Department of Trade and Industry; and the Department of Health on how they have responded to the listeriosis outbreak and what is currently being done to address the crisis.

The committees welcomed the fact that the Department of Health announced listeriosis as a notifiable disease. The members, however, were very concerned to learn that there are no compulsory specifications for listeria and standards on processed meat products are voluntary on the part of the producers. In this regard, the committees highlighted the urgent need for the Department of Trade and Industry to develop norms and standards for all processed meat products.

In addition, the committee requested the fast-tracking of the establishment of the Food Control Agency, to ensure strengthened inter-governmental relations and coordination of food safety practices.

The committee resolved that after three months, both portfolio committees should sit again for a progress report and feedback from the three departments, including the Department of Planning, Monitoring and Evaluation.

 

The Department of Health says while traces of Listeria were found at RCL Foods’ processing facility in Wolwehoek, in the Free State, the facility was not responsible for the recent listeriosis outbreak, reports Fin24. This comes after RCL Foods released a statement earlier in March saying a French lab which tested the same facility also found that the ST6 strain, which caused the listeriosis outbreak, was not present there.

The department said that the results of laboratory tests done on environmental samples collected from the Wolwehoek production facility showed Listeria monocytogenes. “However, whole genome sequencing has confirmed that the strains found in the production facility are not the ST6 outbreak strain which has caused 91% of the human cases during the outbreak,” it said. This corroborates the finding of an investigation into the plant by a French laboratory, it added.

However, the department said that these findings do not change the department’s announcement earlier in the month that Listeria had been found at Wolwehoek.

The report said the department briefed Parliament to clarify that the danger that Listeria monocytogenes presented to consumers depended largely on the amount of monocytogenes found at a facility or on an item, saying small amounts of Listeria were not sufficient to cause illness.

 

The government has, meanwhile, urged consumers to observe all sell-by and use-by dates for ready-to-eat products. eNCA reports that this is despite all meat being inspected at abattoirs and processing plants.

“While meat legally placed on the market by abattoirs and processing plants has been inspected and passed as safe for human consumption, care must be taken by consumers to ensure that there is no post-production contamination of the meat and that the meat is properly cooked and kept in a hygienic environment and correct temperatures,” the Departments of Agriculture, Forestry and Fisheries; Health; and Trade and Industry are quoted in the report as saying.

Earlier, Motsoaledi, said that three meat processing facilities have been implicated in the current listeriosis outbreak and therefore been closed, their export certification taken away and the implicated products had been recalled. Trade and Industry Minister Rob Davies confirmed that immediately on being informed of the affected products, the necessary notice to recall them was issued by the government through the National Consumer Commission.

“Samples have been taken at these facilities and confirmatory tests conducted to determine whether or not the listeria found is, in fact, the sequence types that are of public health concern at the moment,” the department said. “The affected facilities will be monitored for implementation of corrective actions and once all the relevant regulatory authorities are satisfied with the measures taken, they will be permitted to continue their operations. Further investigation of the origin, including mechanically deboned meat (MDM) … is underway.”

Davies highlighted that if imported products were found to be the origin of the current listeriosis outbreak, swift action would be taken to protect food safety in South Africa. Currently, imported MDM was being sampled for microbial contamination and since the beginning of March the testing regime had included listeria.

Agriculture, Forestry and Fisheries Minister Senzeni Zokwana said he was informed by the National Agricultural Marketing Council that it was still too early to assess fully the impact of listeriosis on the food basket and that the impact of product recalls might only be evident within the next three to four months.

“The government remains concerned about agricultural commodities, including meat and meat products unrelated to the current outbreak of listeriosis and even fruits and vegetables from South Africa that are being banned from being imported and taken off the retail shelves in countries to which South Africa exports such products,” the joint statement read.

“This is a concern since these products do not pose any risk to consumers and have been certified safe for human consumption by our competent certifying official veterinarians.”

NICD material
Business Day report
NICD Listeriosis Situation Report
Eyewitness News report
Sowetan report
Report on the Polity site
Fin24 report
eNCA report


Receive Medical Brief's free weekly e-newsletter



Related Posts

Thank you for subscribing to MedicalBrief


MedicalBrief is Africa’s premier medical news and research weekly newsletter. MedicalBrief is published every Thursday and delivered free of charge by email to over 33 000 health professionals.

Please consider completing the form below. The information you supply is optional and will only be used to compile a demographic profile of our subscribers. Your personal details will never be shared with a third party.


Thank you for taking the time to complete the form.