Listeria Outbreak: What’s the fuss?

Early 2017, South Africa was plagued by an outbreak of Listeria. Since the outbreak occurred, the Department of health in SA has found the source and has established measures to control and eliminate the bacteria. The outbreak has however affected how people view and consume ready-to-eat and processed meat products. In March 2018, there were still some cases of Listeriosis affecting some consumers. At the time I wrote an article regarding the outbreak, but did not publish it. I have decided to publish it on the blog as there has been news over the weekend of a Salmonella outbreak in Durban, South Africa. I will wrote a separate blog regarding the Salmonella outbreak as it tackles a different issue than that of the Listeria Outbreak of 2017. I have inserted the article I wrote regarding the Listeria Outbreak below.

The purpose of this article, is to inform consumers about listeria without all the scientific terms, understand how ready-to-eat meats are manufactured, the significance of ready-to-eat meats in South African culture.

In recent news, South Africa has been affected by a bacterial outbreak of Listeria monocytogenes, that has claimed the lives of at least 180 people and further infected almost 1000 people since the outbreak was discovered in January 2017. The Department of Health (DoH) in South Africa has announced that Enterprise Meats and Rainbow Chicken manufacturing plants have been identified as the source of the outbreak, and has instigated a nationwide recall on all ready-to-eat processed meats produced by these companies. It did not take long for the retailers to follow suite and recall all the ready-to-eat processed meat products on their shelves as well. And as one could imagine, many consumers are panicked as they fear for their health and the health of their family members who may have consumed possibly contaminated product. On the other hand, we have consumers who are nonchalant about the recall and who believe that that may not get infected, as they have not gotten sick yet; as a Food Technologist I am deeply concerned with the consumers on both ends of this recall.

Ready-to-eat processed meat products are significant in South Africa, their significance can be attributed to their low cost, versatility, shelf-life and availability on the market. Usually vienna’s and polonies have a low-cost point and are seen to versatile in that they can be eaten as is, put on bread or rolls, fried etc. Street food vendors or fast food / take-away shops often add vienna’s, polony or Russian sausage to dishes such as the “kota” and “gatsby” which are often very affordable and filling. For those who don’t know, a ‘kota’ is a quarter loaf of bread that has been hallowed out and then filled with a combination of slap chips, eggs, cheese or atchar and topped with Vienna, polony or Russian sausage (Ndabezitha, 2016). A ‘gatsby’ is foot long roll that is cut opened, filled with slap chips, sauce/atchar and topped with polony, Vienna or Russian sausage (other meats may also be used), this is usually cut and divided between 2- 4 people (Morris, 2017).

Consumers may be wondering how this outbreak could occur and what the manufacturers could have done to prevent it. In the food industry throughout the world, food safety is a major topic. In South Africa, the DoH has set out minimum requirements for food manufacturers and have various laws and regulations in place to guide food manufacturers with regard to producing safe product for South African consumers. These guidelines include information and limits for micro-organisms. Retailers may also have their own food safety standards that they apply to food manufacturers to ensure that they sell safe food products to their customers. These standards are usually adopted from world recognised standards; third party certified auditing bodies are then selected to audit the food manufacturer to ensure that the standards and requirements are met (Gardner, 1993).

Typically outbreaks of this nature are to poor implementation of the standards or lack of effectiveness of implemented standard. In a food manufacturing plant there is a cleaning and sanitation programme as well as a microbiological control and monitoring programme. These programmes go hand-in-hand. The cleaning and sanitation programme includes personal hygiene, personal protective equipment and cleaning and sanitation of the facility and equipment (Grinstead, 2006). The microbiological programme monitors the effectiveness of the cleaning programme (example: is the cleaning protocol effective in removing physical dirt as well as removal or elimination of micro-organisms).

Listeriosis is food poisoning that occurs due to the contamination of the bacteria Listeria monocytogenes. L. monocytogenes is a bacterium that is found throughout the environment, this includes sand/soil, air, water, vegetation and sewage. As it is found in the environment animal products such as meats and dairy products are often most affected by this bacterium. Listeria was discovered in the 1800’s, so it’s been around. It is found to be a Gram-positive bacterium which is typical of a pathogen (they have strong cell walls and can cause disease). They usually grow in anaerobic condition (no oxygen required for survival), grow at temperatures of 0- 45˚C, this includes refrigeration temperatures and room-temperature. Listeria has a pH tolerance of 4.5 – 9.4 (acid to neutral), can grow in low water activity area’s and are not scared of salty conditions. These conditions basically describe most food products (Nations, 2004). L. monocytogenes is a resilient bacterium that affects those with weakened immune systems (the elderly and young children).

Listeria usually contaminates food post-processing or during handling but poor processing conditions or poor heat treatment can also lead to contamination. Poor hygiene condition of the manufacturing facility and equipment or poor hygiene practises by staff may also lead to contamination. Contamination of L. monocytogenes can also occur during preparation of food products in the household if surfaces and equipment is not adequately clean or the food handler has not washed their hands after coming in contact with the bacteria. When a food product is contaminated by Listeria, there is no difference in the smell, taste or appearance of the food product (Grinstead, 2006).

Ready-to-eat processed meats like polony, vienna’s or Russian sausages may be more prone to contamination by L. monocytogenes as it is manufactured using various meat products that could come from different sources. The ingredients in processed meats usually contain similar ingredients which includes:

  • Mechanically de-boned meat (chicken, pork or beef)
  • Water
  • Vegetable Protein (textured or powdered Soya)
  • Starch
  • Salt
  • Wheat Gluten
  • Sugar
  • Phosphates
  • Maltodextrin
  • MSG (Monosodium glutamate)
  • Spice
  • Sodium erythorbate (for colour)
  • Sodium Nitrite (preservative)
  • Sodium Nitrate (preservative)

Except the meat ingredients the other ingredients are usually used for bulking, emulsification and flavour. The ingredients are usually grinded, minced or bowl cut together to create a thick paste like emulsion. The emulsion is then automatically filled into casings, clipped and then either steamed, smoked or steam smoked (smoking can add to colour and flavour) (Tauber, 1984). The whole manufacturing process of these processed meats includes a handling process and transfer from one machine to the next. Any un-clean or contaminated item may come into contact with the product at any time.

As consumers we need to be aware of what is happening in the food industry and how we can be “food safe” in our own homes or where we consume food. Consumers are also to follow directives regarding the product recall by the DoH. It is important that any products listed to be recalled is returned to the retailer. It cannot be confirmed that the products you have stored in your refrigerator are contaminated, there is a possibility of contamination. Consumers should not panic; the Listeria outbreak has been active for more than a year now. Hence, we should fuss about this outbreak and the further findings by the DoH, we want to consume safe products and maintain our health. If consumers are concerned that they might be infected, they should seek medical advice. Clearing and cleaning out your refrigerator may help eliminate any cross-contamination. Diluted bleach and warm water, with a clean sponge or cloth are good tools to use for cleaning. Bleach has an antimicrobial effect on micro-organisms, one could also lightly wipe down containers or bottles with diluted bleach and water before returning the items to the refrigerator. It is advisable that food (especially meat products) be thoroughly cooked before serving. Maintaining the cold chain and adequately sealing food products is also important to limit the exposure or growth of micro-organisms. Listeria is motile (can move) at temperatures of 20 – 25˚C, so once cooked food has cooled, best practice is to cover the food and store it in the refrigerator (Nations, 2004).


Gardner, S. (1993). Consumers and Food Safety: A Food Industry Perspective. In Food, Nutrition and Agriculture.

Grinstead, D. (2006, 11 12). Retrieved from Food Manufacturing:

Morris, C. (2017, 05 25). The Gatsby Sandwich. Retrieved from Cape Town Magazine:

Nations, F. a. (2004). Risk Assessment of Listeria Monocytogenes in Ready-to-eat Foods:. In F. a. Nations, Risk Assessment of Listeria Monocytogenes in Ready-to-eat Foods: Technical Report. Rome, Italy.

Ndabezitha, T. (2016, 12 02). South African street food: 5 great kotas in Gauteng. Retrieved from Eat Out:

Tauber, A. M. (1984). Processed Meats. In F. T. A.M. Pearson, Processed Meats. Westport, Connecticut: The AVI Publishing Company, inc.


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