All of us have at least once got sick after taking in of contaminated food. This condition is called food poisoning. The microorganism or the toxin enters the body through the gastrointestinal tract and causes the symptoms like; tendency to vomit, vomiting, and cramps in the stomach, diarrhea, fever and thus body become weak.
Food may be contaminated with bacteria, viruses, chemicals or even poisonous metals. Most of the food poisoning cases arise due to attack of bacteria. Bacterial contamination does not always cause fouling of food. But it may be capable of causing health problems. Staphylococcus aureus is the commonest bacteria that cause food poisoning by producing toxin.
Foods such as dairy products, meat, chicken, eggs, etc has to be properly cooked or refrigerated before use. Bacteria have the ability to reproduce at a fast rate, especially at 37-380C and in the presence of moisture. Improper storage condition is also a very important factor that causes poisoning. When the prepared food is kept uncovered, or when the person handling the food touches his body during handling, all these contribute to passing germs to the food. Sneezing, coughing or licking the fingers during food preparation all contaminates the food.
Even fresh and good foods can be cross contaminated by contaminated food during storage. Use of same chopping boards for cooked and uncooked foods also results in cross contamination.
Infections causing bacteria; E.coliO157, Salmonella, Vibrio are seen in eggs, shell fishes, oysters, etc. Listeria monocytogenes and Yersinia enterocolitica are food pathogens which easily grow under refrigerated temperature. Clostridium botulinum isa paralytic toxin producing food pathogen commonly seen in canned foods.
Warmed-over left over’s kept without refrigeration, often support the growth of Salmonella. The left open cans of canned foods are more susceptible to Salmonella invasion.
Clostridium perfringenes are commonly involved in meat, fish and poultry products. Cooked meat, allowed for slow cooling and held for sometime before consumption are effortlessly attacked by this bacterium.
Bacillus cereus usually seen in curds, cereals, puddings, etc. causes gastroenteritis due to an enterotoxin produced by it.
Campylobacter species are found in red meat, ground beef, etc. Listeria infection is spread through infected chicken, water, milk, etc.
Shigella is usually spread through improper handling. A virus, Norovirus is also a food pathogen causing gastrointestinal problems, vomiting, diarrhoea, etc. Poisonous mushrooms has often been mistaken and results in the developing of food borne illness.
Some other diseases that spread through food also include brucellosis, Q fever, scarlet fever, septic sore throat and infectious hepatitis.
Fruits and vegetables which are consumed raw should be taken in only after proper washing with chlorine solution or water. Where night soil is used as a fertilizer, there is a great risk of intestinal pathogens being present on fresh salads.
Principle underlying the prevention of food-borne illness is to prevent the transfer of the pathogen from its source to the food. Shellfish from polluted waters and milk from diseased cows should not be entertained. Meat should be taken only after proper cooking. Food handlers should be kept away from work while ill or during recovery.
