Listeriosis – the biggest outbreak in history

Ian Nkala describes how the outbreak has affected thousands of people in South Africa and Zimbabwe, and how the origins of the outbreak are emerging.
calendar icon 26 March 2018
clock icon 7 minute read

A listeriosis outbreak that, by mid-March, had sickened around 1,000 and killed 183 people in South Africa since January, has caused alarm in consumers and resulted in the recall of thousands of processed meat products from supermarket shelves. Zimbabwe, which imports some processed meats from its richer neighbour, is also facing widespread recalls and worried consumers.

The outbreak, described by the World Health Organisation as the biggest in world history, forced South African retailers to recall at least 3,500 tonnes of a ready-to-eat sausage, also known as polony, viennas, ham, meat spreads, corned meat, salami and pepperoni.

The South African government identified two factories in northern Limpopo province near the border with Zimbabwe as the source of the contamination. Some 16 samples from the plant tested positive for the Listeriosis monocytogenes bacterial strain ST 6, which is highly virulent.

Some of the ready-to-eat foods produced by Colcom, Zimbabwe’s largest pork producer. Colcom have issued a statement saying that their chilled meat products are safe from listeria. Source:

“We import the bulk of processed meats that you see on the market from South Africa,” said Osman Hlabangana, a retailer in Cowdray Park, a high-density residential suburb in Bulawayo, Zimbabwe’s second largest city.

“Omalayitsha (Ndebele language slang for unlicensed road carriers known for smuggling goods from South Africa) bring them from there. Although we import, the imported meats are cheaper than local brands. They are very popular not just because of affordability but customers say they taste better than what you get locally. I had to destroy some of the stock we had when news about the disease broke. That was a loss but I operate in a residential area and personally know many of my customers so I asked myself, ‘what if a person I know buys pork pie from here and gets sick after eating it?’”

Zimbabwe imports large amounts of cold meats from South Africa, because local output is too low to meet demand. A substantial part of the imported food stuffs are pork-based as output is depressed due to high stock feed costs and low producer prices. This has been exacerbated by a cash shortage that has reduced consumer spending over the past two years.

The Livestock and Meat Advisory Council reported late last year that “the total number of pigs slaughtered between January and August 2017 was 102,254, 9% fewer than the corresponding period in 2016”.

Zimbabwe banned importation of ready-to-eat meats from South Africa on 6 March, some 47 days after the listeriosis outbreak.

Announcing the ban, Gerald Gwinji, the permanent secretary in the Ministry of Health said:

"What makes this outbreak significant for us is that we do import quite a significant [amount of] food items, particularly cold processed foods into Zimbabwe from South Africa.

"What we have done as a country is tightening our food surveillance at border posts. We are still to discover any batches of the food items in question, but the fact that South Africa has recalled specific products it means that the products might no longer be on the market. However, we continue to increase our surveillance at the border posts and should products be found at the borders we advise our border control officers to confiscate, quarantine and send for destruction.”

Namibia, Botswana, Kenya, Malawi, Mozambique, Swaziland, Zambia and Zimbabwe have also banned South African meat imports.

Retailers in Bulawayo, in southern Zimbabwe near South Africa, fill up their shops with South African items as local industry continues to underperform. Almost all the foods that are sold by vendors in the city are imported from that country.

According to the Zimbabwe Statistical Agency the country imported goods worth US$4, 5 billion in the first 10 months of 2017 with South Africa contributing 41 percent of the imports worth US$1, 8 billion.

“I am concerned because most families here buy food items made there (South Africa). I think the government was late in effecting the ban if you consider that the disease was reported in January and the ban was effected this month. Some might have eaten contaminated food over that period,” said Noma Mthombeni, a mother of five, also of Cowdray Park.

Colcom, Zimbabwe’s largest pork producer has assured its customers that its products are safe from listeriosis. The company said in a statement that all processed meat products it sells are locally made.

Colcom's delivery vehicles taking loads of processed foods from the Harare factory to the market. The company, Zimbabwe's largest pork processor, has said its products are safe from listeriosis. Source: The Financial Gazette.

“Colcom foods does not import processed meat products from South Africa. Our safety management systems are based on the International Hazard Analysis and Critical Control Point system, managed by a dedicated quality team. We at Colcom Foods prioritise the health and safety of our customers above all else,” said Colcom, adding that it had upgraded the capabilities of its laboratory to test an increased range of microbiological factors including listeria.

The media have seen an opportunity for Zimbabwean pork producers to enhance their output to meet the supply gap occasioned by the government ban on South African products.

FinX, a local business news publication, said Colcom should “fully service the local market and create brand loyalty that will be difficult to break by the time the ban will be lifted. However, it will also require them to be competitive and diversified as consumers in a low-income country such as ours mainly base their buying decision on price”.

Growers are looking forward to higher demand for domestically grown and processed pork products, said Zimbabwe Commercial Farmers’ Union president, Wonder Chabikwa, but the ban will do little to address the underlying factors that have weighed down swine production in recent years.

The price of stock feed, which constitutes between 75 and 80 percent of a swine farmer’s production costs, should be more affordable.

“The ban is an opportunity for the industry. It means the focus will shift to what we produce locally. Even if a retailer somehow manages to bring South African produce, I don’t see any customer risking their health by buying the imported item. However, on its own, the ban will not increase farm production or reduce the price of stock feed.

"What I am saying is the price of stock feed must reflect the fact that we have raw materials locally after last year’s big harvest. None of the stock feed manufacturers are importing maize for use in making pig feed. The excuse that stock feed prices are always high because of the import component does not hold water now, so there is need to correct the price of stock feed,” said Chabikwa.

He however encouraged pig farmers to grow their own maize and process it into stock feed for their animals to cut costs.

There are fears that the incidence of the disease in southern Africa is higher than reported since the disease is not notifiable and that other countries in the region lack capacity to conduct tests to confirm the disease. One case was reported in Namibia, South Africa’s western neighbour on 12 March.

Cognisant of that risk, South Africa’s Health Minister, Aaron Motsoaledi held an emergency meeting on 15 March with his regional counterparts to discuss ways to respond if the outbreak spreads to other countries. He warned that more cases of the disease are likely.

Confederation of Zimbabwe Retailers president Denford Mutashu said members of his organisation have removed South African foods that might carry listeriosis, adding, "Business is not just about profit but the health of customers as well. The ban on imports is in place, which is good, but we have always called on the government to strengthen border controls to curb smuggling.”

By Ian Nkala

Ian Nkala is a Zimbabwean journalist based in Harare. He reports widely on agriculture in Zimbabwe and southern Africa.

Emily Houghton

Editor, The Pig Site

Emily Houghton is a Zoology graduate from Cardiff University and was the editor of The Pig Site from October 2017 to May 2020. Emily has worked in livestock husbandry, and has written, conducted and assisted with research projects regarding the synthesis of welfare and productivity of free-range food species.

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