Ina Opperman

By Ina Opperman

Business Journalist


Worried about food poisoning? This is what you should know

Food poisoning happens when several microorganisms or their toxins are present in food at high enough levels to cause illness.


Understanding the facts about food poisoning can help you prevent it and keep you informed about what to do if you or someone you know gets it.

Food poisoning is a real threat, especially as load shedding can affect the cold chain that is supposed to keep food safe, while the hot summer months can also cause food to be infected with viruses and bacteria.

In an advisory note about food poisoning that was compiled in collaboration with Prof. Lucia Anelich from Anelich Consulting, the Consumer Goods and Services Ombudsman (CGSO) says although most people who have food poisoning recover within a day or two and do not need to seek medical help, the condition can become more serious and cause longer term medical conditions, while some of the most extreme cases may even be fatal.

Bacteria and viruses are the more common micro-organisms that cause food poisoning and are commonly referred to as pathogens. However, not all foodborne pathogens cause the same symptoms.

The CGSO says some examples of foodborne bacteria and viruses are salmonella, listeria, staphylococcus aureus, certain types of E. coli, shigella, campylobacter, clostridium botulinum, norovirus and Hepatitis A virus.

The most common symptoms of food poisoning are, according to Prof. Anelich, vomiting, stomach cramps, diarrhoea, nausea, fever, headache, muscle aches, shivering and tiredness or fatigue. You can have more than one symptom at the same time in some cases.

With norovirus, also known as stomach flu, you can vomit and have diarrhoea at the same time, with some shivering and tiredness.

ALSO READ: Two toddlers in West Rand die after eating ‘poisoned’ snacks

Other illnesses could have same symptoms

However, Prof. Anelich says a number of other illnesses have the same symptoms, which makes it difficult to determine if you actually have food poisoning when you show these symptoms.

When people who ate the same food at the same time as you from the same source are showing similar symptoms, it is usually a good indicator of food poisoning.

Some bacteria also target vulnerable sectors of the population, such as young children, people over 65, pregnant women, new-born babies and people with compromised immune systems. People who are living with HIV/Aids or who are under-nourished, undergoing cancer treatment, had an organ transplant and are on immuno-suppressive drugs to avoid the body rejecting the organ, are particularly vulnerable.

The last time a food-borne disease affected many South African consumers was in 2018 when an outbreak of the Listeria monocytogenes bacteria caused listeriosis which has a mortality rate of 20-30%.

This outbreak caused 209 deaths, including 91 babies and it infected more than 1 000 people. The origin was traced to Tiger Brands’ Enterprise facility in Polokwane, Limpopo. People contract listeriosis when they eat contaminated food.

Listeriosis symptoms include muscle aches, fever, stiff neck, confusion, convulsions and sometimes even septicaemia, while it can also lead to miscarriages, stillbirths, premature delivery or life-threatening infection of new-born infants, such as meningitis. However, listeriosis usually have mild symptoms which pass with no further consequences and people often do not even know they had it.

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E.coli another serious bacterial disease

E. coli O157:H7 is another serious bacterial disease that causes different symptoms and tends to target young children. It typically causes bloody diarrhoea and causes a significant number of deaths while it can affect the kidneys for life, requiring people be on dialysis.

It is important to remember that not all food poisoning organisms are found in all foods and different organisms have different “preferences” for foods they can grow on or survive in.

The ombudsman says a rule of thumb is that cooked foods are generally safer than uncooked foods, provided these are thoroughly cooked and consumed quite soon after cooking.

It is also very important to keep thoroughly cooked foods refrigerated for a maximum of a few days. Cooked foods can also be potentially dangerous under certain circumstances, such as when food is not prepared under hygienic conditions creating a potential for certain heat resistant bacterial toxins to be produced in the food.

In this case, cooking may destroy the bacterial cells, but not necessarily the toxins, which may then make you ill. The food could also be contaminated after cooking and if it is not reheated thoroughly before eating it, it can make you sick.

ALSO READ: Listeriosis death toll climbs to 189

Close association between pathogens and certain foods

These are examples that illustrate the close association between pathogens and certain foods where foodborne outbreaks have been listed before:

  • Listeria in soft cheeses and certain deli meats
  • E. coli O157:H7 in undercooked minced meat, such as hamburger patties
  • Salmonella in poultry, other meat products and eggs
  • Clostridium botulinum that causes a severe illness called botulism in traditionally-home-prepared salted or fermented foods, such as fish or cured meats and improperly home-canned products.

The ombudsman stresses that most food products in the formal food sector are safe for human consumption. “These foods are produced in plants which undergo regular hygiene and food safety audits to ensure that the food is produced in an environment with good hygiene and good manufacturing practices.”

How do microbes then get into the food? According to the ombudsman, several factors determine how foods become contaminated with bacteria, viruses or other microorganisms that can cause foodborne illness, such as:

  • Improper hygiene among people handling the food when they do not regularly wash their hands, particularly after being to the toilet and sneezing or coughing into their hands.
  • Inadequate cleaning and disinfection of surfaces and the environment. A number of food poisoning incidents occur when cooked food is handled on a surface where raw food was handled and the surface was not cleaned and disinfected first. The raw food’s juices can contain pathogens which can be transferred to the cooked food. This is called cross- contamination and is also applicable to any utensils you use.

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