Listeriosis: 10 things we know so far

On Tuesday‚ the Department of Health announced that South Africa had an outbreak of the food-borne disease listeriosis.

A total of 557 cases have been reported this year alone‚ a steep jump from the average of between 60 and 80 reported in previous years.

Health Minister Aaron Motsoaledi said the disease had resulted in 36 deaths.

Here are 10 things we know about the disease thus far:

1) The department said it does not have any readily available data on past mortality rate figures associated with listeriosis as it was previously not flagged as a notable disease.

2) The alert of a possible outbreak was noted in July when Gauteng doctors from neonatal units in the Chris Hani Baragwanath and Steve Biko Academic hospitals raised the alarm when they recorded an unusually high number of babies with listeriosis.

3) Gauteng accounted for the bulk of the cases‚ with 345 reported thus far. The Western Cape had the second-most reported cases (71) followed by KwaZulu-Natal with 37 cases.

4) There are four possible sources of the disease -

• where food is collected‚ e.g. farms

• food processing plants

• retail stores

• food preparation at home

5) The health department believes this particular outbreak of listeriosis is most likely because of the contamination of food from farms or food processing plants but the source is still being investigated.

6) The health department said the large proportion of cases across the public and private health sectors (66% and 34% respectively) indicates that the source of the outbreak is likely a food product that is widely distributed and consumed by people across all socio-economic groups.

7) There is no vaccine to prevent infection. However‚ preventative measures include -

• Washing hands before handling food and during food preparation.

• Separating raw food from cooked food.

• Cooking food thoroughly and never eating half-cooked or uncooked food‚ especially meat products. Food that does not need cooking needs to be thoroughly washed with clean water.

• Keep food at safe temperatures.

• Clean water for domestic use at all times and use pasteurised milk products. In domestic situations where pasteurisation is not possible‚ boil the milk prior to use.

8) The most common foods to be contaminated are raw or unpasteurised milk as well as soft cheeses‚ or vegetables‚ processed foods and ready-to-eat meats and smoked fish products.

9) Symptoms for someone who has the disease include flu-like illness‚ diarrhoea accompanied by a fever‚ general body pains‚ vomiting and weakness. It can also lead to infection of the bloodstream‚ or septiceamia‚ and meningitis - an infection of the brain.

10) Listeriosis is treatable and preventable.