Dr. Syeda Sadaf Akber
Food borne Illnesses
Food-borne illness, also referred to as ‘food poisoning’, is caused by eating food contaminated with illness-causing pathogens. Food-borne illnesses are infections or irritations of the gastrointestinal tract caused by food or water that contain harmful bacteria, parasites, viruses, or toxic chemicals. Common symptoms of food-borne illnesses include vomiting, diarrhea, abdominal pain, fever, and chills. Most food-borne illnesses are happen suddenly and last a short time, and most people recover on their own without any treatment.
Once a contaminated food is eaten, illness can be caused by the pathogens themselves, which called food-borne infection; caused by toxins produced in the food by pathogens, called food-borne intoxication and when caused by toxins produced in the body by pathogens is called food-borne toxin infection.
The causes of food borne illness can describe as Biological hazards include bacteria, viruses, and parasites. Bacteria and viruses are responsible for most food-borne illnesses. Chemical hazards include natural toxins and chemical contaminants. Some natural toxins are associated with the food itself like mushrooms and crustaceans shellfish, some are made by pathogens in the food when it is time and temperature abused. Chemical contamination can occur when products like cleaners are not used correctly. Food allergens are a chemical hazard. Some people are sensitive to proteins in foods. Some major food allergens include milk, eggs, fish, crustacean shellfish, wheat, soy, peanuts and tree nuts. Physical hazards can include metal shavings from cans and plastic pieces or broken glass.
The conditions that influence bacterial growth are the food itself, acidity, time, temperature, oxygen, and moisture. Most bacteria need nutrients to survive. They obtain these nutrients from food. Bacteria grow best in food that is neutral to slightly acidic. Bacteria need time to grow and they grow rapidly between 41°F and 140°F. Some aerobic bacteria require oxygen to grow, some grow when there is no oxygen, and some can grow with or without oxygen.
Bacteria can cause infections of the GI tract. Some harmful bacteria may already be present in foods when they are purchased. Raw foods including meat, poultry, fish and shellfish, eggs, unpasteurized milk and dairy products, and fresh produce often contain bacteria that cause food-borne illnesses. Bacteria can contaminate food and make it harmful to eat at any time during growth, harvesting or slaughter, processing, storage, and shipping.
Foods may also be contaminated with bacteria during food preparation in a restaurant or kitchen. If food preparers do not thoroughly wash their hands, kitchen utensils, cutting boards, and other kitchen surfaces that come into contact with raw foods, through cross-contamination bacteria spread from contaminated food to uncontaminated food, may occur.
Food poisoning that has been caused by bacteria is the most common cause of food poisoning. Food safety is essential for lowering the risk of bacterial food poisoning because the way food is handled, stored and prepared is directly related to the level of bacteria present on food. Food handlers should maintain a clean and sanitary workspace, ensure their hands and equipment are thoroughly washed to avoid cross-contamination between foods and store, chill and cook foods in and to the correct temperatures.
Salmonella mostly found in raw and under cooked meat, poultry, dairy products, and seafood. Salmonella may also be present on egg shells and inside eggs. Cyanobacteria jejuni is the most commonly reported gastrointestinal bacterial disease found in raw or under-cooked chicken and unpasteurized milk.
Shigella present in the stools of people who are infected. If people who are infected do not wash their hands thoroughly after using the bathroom, they can contaminate food that they handle or prepare. Escherichia coli O157:H7 causes the most severe illness. Common sources of E. coli include unpasteurized fruit juices, milk, and fresh produce. Listeria monocytogenes has been found in raw and undercooked meats, unpasteurized milk and soft cheeses. Vibrio can contaminate fish or shellfish. Clostridium botulinum can contaminate improperly canned foods and smoked and salted fish. The symptoms of bacterial food poisoning depending on the illness and some people suffer from more severe cases than others.
Viruses do not grow and multiply on food. Viruses cause infections that can lead to sickness. Instead virus cells are present on food and when consumed, they begin taking over human cells and infecting them. Infected person can pass viruses to each other. Viruses are present in the stool or vomit of people who are infected. People who are infected with a virus may contaminate food and drinks, especially if they do not wash their hands thoroughly after using the bathroom. Common sources of foodborne viruses include, food prepared by a person infected with a virus, shellfish from contaminated water, produce irrigated with contaminated water.
Norovirus is a common foodborne virus and it is responsible for causing most of the illnesses related to food contamination and causes inflammation of the stomach and intestines.
These diseases vary in severity and will typically last for a few days, with the exception of Hepatitis A which can last for a number of weeks. Hepatitis A is a disease that affects the liver and is spread by coming into contact with anything contaminated by an infected person’s faces. It is very important that individuals who are suffering from one of these viruses do not handle or prepare food or drink for others as there is an added risk of making others sick.
Parasites are tiny organisms that live inside another organism and they multiply in a host cell. Cryptosporidium parvum and Giardia intestinalis spread through contaminated water with the stools of people or animals who are infected. Foods that come into contact with contaminated water during growth or preparation can become contaminated with these parasites. Food preparers who are infected with these parasites can also contaminate foods if they do not thoroughly wash their hands after using the bathroom and before handling food.
Trichinella spiralis is a type of roundworm parasite and people may be infected with this parasite by consuming raw or undercooked pork or wild game.
Harmful chemicals that cause illness contaminate foods such as fish or shellfish, which may feed on algae that produce toxins, leading to high concentrations of toxins in their bodies. Some types of fish, including tuna and mahi mahi, may be contaminated with bacteria that produce toxins if the fish are not properly refrigerated before they are cooked or served, certain types of wild mushrooms and unwashed fruits and vegetables that contain high concentrations of pesticides.
Toxins are designed to cause harm to anything that comes into contact with them and in many cases toxins that cause an individual to become ill can have lifelong consequences. Natural toxins occur as a defense mechanism produced by the food itself as like mushrooms, Red kidney bean toxin, Shellfish toxins, ciguatera and scombroid poisoning and Berries varieties.
Accidental chemical contamination is another reason that food can become toxic and cause someone to become unwell. Pesticides and chemicals are a common type of manmade toxins that can contaminate food and cause illness. When purchasing foods that will likely have been treated with pesticides, for example lettuces, fruit or vegetables, washing is essential.
Anyone can get a foodborne illness but some people are more likely to develop foodborne illnesses than others, including infants and children, pregnant women and their fetuses, older adults and people with weak immune systems.
Common symptoms of many foodborne illnesses are nausea, vomiting, diarrhea or bloody diarrhea, abdominal pain, loss of appetite, fever and chills. Symptoms can range from mild to serious and can last from a few hours to several days. In severe cases, foodborne illness can lead to hospitalization or even death.
- botulinumand some chemicals affect the nervous system of patient, causing symptoms like headache, tingling or numbness of the skin, blurred vision, weakness, dizziness and paralysis. Foodborne illnesses lead to dehydration, hemolytic uremic syndrome and other complications. Acute foodborne illnesses may also lead to chronic or long lasting health problems.
Some foodborne illnesses lead to other serious complications. C. botulinum and certain chemicals in fish and seafood can paralyze the muscles that control breathing. According to a recent study adults who had recovered from E. coli O157:H7 infections had increased risks of high blood pressure, kidney problems, and cardiovascular disease.
People with those symptoms should see a health care provider immediately, signs of dehydration, prolonged vomiting that prevents keeping liquids down, diarrhea for more than 2 days in adults or for more than 24 hours in children, severe pain in the abdomen or rectum, a fever higher than 101 degrees, stools containing blood or pus, stools that are black and tarry, nervous system symptoms and signs of HUS. Diagnostic tests for foodborne illnesses may include a stool culture, in which a sample of stool is analyzed in a laboratory to check for signs of infections or diseases. A sample of vomit or a sample of the suspected food, if available, may also be tested. The only treatment needed for most foodborne illnesses is replacing lost fluids and electrolytes to prevent dehydration. Hospitalization may be required to treat life threatening symptoms and complications, such as paralysis, severe dehydration, and HUS.
Drink plenty of liquids such as fruit juices and caffeine-free soft drinks to replace fluids and electrolytes, gradually reintroducing food, starting with bland, easy-to-digest foods such as rice, potatoes, toast or bread, cereal, lean meat, and bananas and avoid fatty foods, sugary foods, dairy products and caffeine until recovery is complete.
Foodborne illnesses can be prevented by properly storing, cooking, cleaning, and handling foods. Raw and cooked perishable foods should be refrigerated or frozen promptly. Foods should be cooked long enough and at a high enough temperature to kill the harmful bacteria that cause illnesses. Cold foods should be kept cold and hot foods should be kept hot, fruits and vegetables should be washed before eating, cutting, or cooking. Raw meat, poultry, seafood, and their juices should be kept away from other foods to avoid cross contamination. People should wash their hands with warm, soapy water before and after handling raw meat, poultry, fish, shellfish and eggs. People should also wash their hands after using the bathroom, changing diapers, or touching animals. Utensils and surfaces should be washed with hot, soapy water before and after they are used to prepare food. Wash countertops after preparing each food item and before you use it for the next food. Prevent cross contamination when storing food in the refrigerator. In the refrigerator, store raw meats, fish, and poultry below ready-to-eat and cooked foods.
During cooking color is not a reliable indicator that the food has been cooked to the correct temperature to ensure that foodborne pathogens are destroyed. Time as an indicator that the food is cooked properly could result in a potential food safety hazard. However, different thicknesses of a food or ingredients that are used can alter the time needed at a specific temperature to make sure the food has reached the correct temperature to kill all pathogens. Refrigerate and freeze meat, poultry, eggs and other perishables as soon as possible after purchasing.
There are three safe ways to thaw food like in the refrigerator, in cold water, and in the microwave. Food thawed in cold water or in the microwave should be cooked immediately. It is important to place the food in a bag that will prevent the water from entering. Cook food immediately once thawed because some areas of the food may become warm and begin to cook during the thawing process. Cool leftovers quickly by dividing large amounts into shallow containers for quicker cooling in the refrigerator. Cover any cuts with waterproof bandages and do not prepare food for others if you are sick or have a skin infection.
