On Monday Health Minister Aaron Motsoaledi announced that there were 61 deaths and 727 laboratory-confirmed cases, but the NICD’s Dr Juno Thomas said that new data shows that the number of cases has risen to 82.

She said that as more cases are tracked, and the outcomes of patients recorded, the “death toll will become higher”. So far only 238 cases have a definite outcome: where the NICD can confirm if the patient has been cured or died from the disease.

According to the World Health Organisation (WHO) listeriosis infection is caused by the bacterium Listeria monocytogenes, and is usually transmitted through contaminated food and causes symptoms like fever, muscle aches, nausea and diarrhoea.

The source of the outbreak is yet to be confirmed but people have become sick with the infection in all nine provinces and across all socio-economic groups, with the highest number in Gauteng.

Rich and poor

“To date 34 percent of cases have come from the private sector and 66 percent from the public and when you think that less than 20 percent of the population relies on private health services it certainly is a signal that the risk is not limited to those living in poor socio-economic conditions,” Thomas said. “The sense we’re getting is that the source is a single contaminated food commodity, or small group of commodities from the same facility, that is or are very popular and accessible to all South Africans across the board.”

According to Thomas, the wide-range of people affected shows that the contaminated food source is unlikely to be a “luxury product” like soft cheeses or seafood but could be a widely-consumed processed meat or dairy product. However, they have not ruled out the possibility of fresh and frozen fruit or vegetables as being the culprit.

The bacteria is readily killed by heat so experts suspect the source to be a food product that does not need to be cooked and is bought ready-to-eat, “for example polony or sausages”.

She said the NICD and Department of Health (DoH) are doing “everything possible” to locate the source including visiting the homes of each patient with confirmed listeriosis infection and testing “everything and anything” in the fridge, freezer and food cupboard “from condiments to ice-cream”.

Country-wide inspections

The DoH has facilitated inspections of production, processing and packaging facilities involved in meat and poultry, as most patients have reported consuming these products.

“This testing is happening in all nine provinces and the dairy and fresh and frozen produce industries will be inspected next,” she said.

Professor Laetitia Rispel from the University of the Witwatersrand’s School of Public Health said that it is possible that deadlier outbreaks have occurred in other countries but that South Africa’s “relatively sophisticated laboratory and diagnostic infrastructure” has allowed the local epidemic to be meticulously tracked and placed it on record as the worst in world history.

“The reason it is proving so difficult to locate the source is that it has affected people across the entire country and you can just imagine the massive number of outlets involved in food production and processing that need to be tested,” she said. “The time and resources needed for such an investigation is extensive.”

Rare infection

She said that the situation is compounded by the fact that listeriosis infection is relatively rare, with an average of between 60 and 80 annual cases, and many clinicians might not be well-versed in suspecting this particular bacterium.

Listeriosis is both treatable, taking between two and six weeks to treat, and preventable through safer preparation of food. But many healthy individuals experience mild symptoms or none at all.  New-born babies, pregnant women and people with compromised immune systems are most at risk of becoming sick or dying.

Thomas said that almost half (42 percent) of the deaths have occurred in infants under one month of age who contract the infection from their mothers while in the womb.

“Even if we haven’t confirmed the source with absolute certainty but have a high suspicion of what it could be, we will inform the public immediately – this is our obligation,” she said. “In the meantime we are cautioning high-risk groups like pregnant women and people living with HIV to be cautious of ready-to-eat products like processed meats and to heat food thoroughly before eating.” – Health-e News.

Five ways to protect yourself

While the source of the outbreak remains unknown, the NICD has directed the South African public to follow the WHO’s guide to safer food to help protect themselves from listeriosis, and for general food safety:

1. Keep clean: Wash hands thoroughly before and during food preparation as well as after using the toilet. Keep food preparation surfaces clean and protected from animals.
2. Separate raw and cooked food: In particular, keep meat, poultry and seafood separate from other foods and store raw and prepared foods in different containers.
3. Cook food thoroughly: Meat, poultry, eggs and seafood should be cooked thoroughly and at high temperatures. Previously prepared food should also be reheated thoroughly.
4. Keep food at safe temperatures. Avoid leaving cooked food at room temperature for more than two hours, keep cooked food hot prior to serving and don’t leave food in the refrigerator for too long.
5. Wash raw foods thoroughly in clean water, especially fruit and vegetables. Select fresh produce where possible and avoid using foods past their expiry date. – Health-e News