Food poisoning

Food poisoning does not mean that somebody else has placed poison in your food. It is an illness caused by eating food or drinking water that is contaminated, spoiled or toxic and therefore made unsafe for consumption. Here, certain micro-organisms have found their way into your food and are able to reproduce and multiply there. It is the multiplication of these organisms that frequently makes food the poison that it then becomes. It is a very common problem and it is estimated that in Nigeria, there may be as many as 1.5 million cases yearly. The good news is that the disease is often of a short duration lasting only a few days or at worst, a few weeks. It is often self-limiting and can usually be recognised for what it is by the affected person. It is similarly spread through contaminated water or food.

Food can become contaminated at any stage during its production, processing or cooking. It can especially become contaminated by not cooking it properly.

A good example is meat. It may also suffer from contamination with various bacteria when food that is meant to be refrigerated is not chilled at temperatures below 5o Celsius. This problem can also arise when cooked food is left in the open and is not refrigerated for a long time. When you eat food that has been touched by someone who is ill or has got diarrhea and vomiting already, you are definitely at risk of catching the infection because that food is contaminated. A similar thing happens when a chopping board is used to cut up contaminated chicken and the same unwashed board is used to prepare vegetable salad; cross contamination results and food poisoning follows.

Food poisoning can start to manifest within a few hours of eating the contaminated food with features like diarrhoea, nausea, abdominal pain and vomiting.

The abdominal cramps are often severe enough to warrant treatment and sometimes, the symptoms are so profound that formal hospitalisation with the use of intravenous fluids, antibiotics and pain relievers can simply not be avoided. In the main, however, many episodes of this problem frequently go away on its own and cause no untoward effects. Sometimes, dehydration and electrolyte derangements occur making the suggested treatment above necessary.

The most common organisms involved are Salmonella, the bacteria that causes typhoid, Escherichia coli (E.coli), Campylobacter, Shigella or perhaps a virus known as Norovirus, which is often the culprit in outbreaks of this problem on a large scale as in school cafeterias or in ship dining halls.

Sometimes, it is not just the multiplication of bacteria in food that is responsible for the various symptoms caused by the disease; it is rather the fact that the organisms produce certain toxins as they multiply. As a result of this singular feature, the various types of food poisoning can be made educated guesses of by noting the duration of the onset of the disease. That is determined by the time interval between when the food is consumed till when the symptoms become manifest. Some of the most common bacteria involved in these processes are as follows:

1) Staphylococcus aureus is one of the most common bacteria in our immediate environment. It causes food poisoning through a toxin that is formed in food before it is eaten and it is known to cause serious vomiting within one to six hours of eating such food.

(2) Clostridium perfringens causes food poisoning by producing spores which then germinate in cooked meat that is kept in a warm environment such as it is virtually anywhere in our country. The lack of adequate electricity means that cooling exists mostly for a few hours a day or not at all. When such meat is eaten, there may be profuse diarrhoea within eight to 12 hours of consuming it. Habitual suya eaters should beware.

 (3) Shigella species can contaminate both food and water, cause severe dysentery which is a severe form of diarrhoea that contains both mucus and blood. Sometimes, the people who contract this infection are very ill with no alternative but hospital admission.

(4) Salmonella also frequently causes food poisoning mostly from poorly cooked or undercooked food, improper handling of eggs and chicken as well as from the contamination of sources of drinking water. In persons who have a weakened immune system such as in those suffering from HIV/AIDS, undergoing treatment for cancer or folks with long-standing liver or kidney disease, people with tuberculosis and among the elderly, this organism can often get into their blood stream and become responsible for potentially life-threatening infections.

(5) Escherichia coli is another harmful type of bacteria which is also the most common cause of traveller’s diarrhoea.  In this case, the stools are just loose at all times. There is no blood in it and no mucus.

(6) Vibro cholerae is usually contracted from contaminated drinking water. It causes a large amount of diarrhoea and also vomiting. The combination of fluid loss from both ends rapidly leads to the development of clinical shock unless such persons are hospitalised and treated aggressively with intravenous fluids and antibiotics.

(7) And then there is botulism, a range of features caused by clostridium botulinum. This produces a toxin which causes fever, diarrhoea, vomiting, numbness, weakness and finally, paralysis. Botulism is transmitted through food that has been contaminated with soil. It is fortunately a rare disease but when it occurs, is often fatal. It is one of the biological warfare agents that international arms control conventions talk about often and is a prohibited agent on that basis as a biological weapon of mass destruction.

(8) Yersinia enterocolitica is known to cause an inflammation of the lymph nodes in the lining of the abdomen and in particular, those around the end of the small intestines and may then produce symptoms that resemble appendicitis.

(9) In temperate countries of the world, most cases of food poisoning are caused by campylobacter bacteria which are found in raw and undercooked meat especially poultry, contaminated water and unpasteurised milk. The onset of the illness is usually between two and five days.

Most of them would have been caused by any of the factors named above. Some others would have been caused by certain specific poisons produced as chemicals from the food we eat especially fish. Many of the victims often complain of abdominal cramps, vomiting, bloody diarrhoea and fever.