South Africa recently experienced the world’s worst outbreak of Listeriosis, a serious disease caused by the bacteria Listeria monocytogenes – which is a common resident in nature, living in soil, water and occasionally in contaminated food. It usually causes a gastro-enteritis (upset tummy / diarrhoea), fever and even meningitis which can be quite severe; but if the patient is immunocompromised in some way (eg HIV or some other underlying disease) or very young or old, or pregnant – then the outcome can be deadly as we saw in early 2018 in SA. Typically someone would contract the disease by eating contaminated unpasteurised dairy products, smoked fish, vegetables or as in the recent outbreak, processed meats. Thankfully most cases are self-limiting – but the more complicated clinical cases need to be treated urgently with specific antibiotics.

The principle challenges in these food-borne disease outbreaks are twofold. Making the initial diagnosis requires a degree of clinical suspicion on behalf of the healthcare practitioner as the features can be quite vague and not pathognomonic of a particular disease. Secondly, identifying the source of an outbreak can be extremely difficult – as the bacteria can literally be lurking in a small sample of a batch of processed meat or one of the soft cheeses. It can survive in a refrigerator even and is considered a particularly hardy character.

So what can you do ? It’s really all about food hygiene. Always be sure to cook food from animal sources (like beef, pork and poultry) thoroughly. If you are doing tartare, be diligent about your food sources. Always wash raw vegetables before eating and keep uncooked meats separate from cooked or ready to eat foods. Avoid unpasteurised milk products. If you ever feel ill and suspect it may be related to something you ate – you should follow a sensible Sherlock Holmes style investigative strategy. Check whether any others who may have eaten the same meal are ill (clue of contaminated food). If present with a fever not settling on simple antipyretic medications, persistent vomiting, headaches, loose tummy not settling – consult a healthcare professional.