Food poisoning is a health problem occurred when people eat contaminated foods or drinks with harmful substances such as bacteria, viruses, and chemicals. The most common cause among them is bacteria.
3 Essential Factors For Bacteria Growth
Bacteria are dependent on 3 factors for survival. Without an ideal combination of these three factors, most bacteria cannot contaminate food before serving.
Food, a source of nutrition for humans is also a source of nutrition for bacteria. Residue from food or garbage usually provides enough nutrition to support infectious bacteria.
Bacteria multiply using the water in food. In an environment where the moisture content is less than 50% bacteria do not grow very well. Bacteria cannot usually survive where moisture content is less than 20%.
Most bacteria multiple between 10 to 60°C (50°F to 140°F) and become most active around 36°C (96.8°F). Storing food below 10°C (50°F) will usually prevent bacteria from multiplying.
Major Causes Of Food Borne Illness
The symptoms and severity of food poisoning vary by bacteria type. SARAYA has outlined the major bacteria and viruses that cause food poisoning. Learn their characteristics to prevent food poisoning.
This infectious bacteria is found mainly in the intestines, and infects through contaminated meat, water or other surfaces. E. Coli can cause infection with as little as 100 cells. It releases a verotoxin that destroys blood vessels in the large intestine, causing cold-like symptoms that lead to diarrhea, bloody feces, severe abdominal pain and vomiting.
Habitat ● Mainly in the intestines of cattle.
Infectious Foods ● Meat and related products such as ground water contaminated by animal feces.
Characteristics ● Only as few as 100 bacteria cells are needed to cause infection. (There are about 100 million E. Coli cells in a peanut size piece of an infected patient's feces.) ● Verotoxins can destroy the blood vessel walls of the large intestine, causing bloody stool.
Incubation ● 1 - 10 days
Symptoms ● Fever, sharp abdominal pain, watery stool, bloody stool, nausea, vomiting. ● Symptoms appear similar to a cold in the beginning, so it is important not to mistake symptoms and delay treatment, especially in those with a weak immune system such as the elderly and children, where it can cause death.
Prevention ● Heat food. Especially, cook meat thoroughly to an internal temperature of at least 70℃ (158°F) for 30 seconds. Do not eat raw meat. ● Wash vegetables thoroughly when eat raw.
Salmonella is a common bacteria, and it is often spread by contaminated food from humans, rodents, and insects to foods. Salmonella infects with a large number of cells that are able to survive in adverse environments. Symptoms of foodborne infection include nausea, fever and diarrhea, and it is often treated with antibiotics.
Habitat ● Widely distributed in the intestines of humans and livestock. Beware infection from mice, flies, cockroaches and pets such as cats and dogs.
Infectious Foods ● Beef, pork, chicken and eggs. Cross-contaminated food.
Characteristics ● Only a small number of bacteria can cause infection. ● Active even in dry conditions.
Incubation ● 6 - 72 hours
Symptoms ● Nausea, abdominal pain (around the navel), fever of approx. 38℃ (100.4°F), diarrhea. ● Once infected, one can be contagious for a long term.
Prevention ● Cook meat and eggs thoroughly. ● Prevent cross contamination. (Wash and sanitize hands, equipment or containers every time after using to handle raw meat or eggs.)
Habitat ● In the intestines of pig, cattle or poultry.
Infectious Foods ● Meat and related products. The contamination rate of chicken is especially high. ● Drinking water such as well water.
Characteristics ● Causes infection with a small number of bacteria. Pet feces can also be a source of infection. ● Microaerophilic bacteria. (Proliferates in an environment with low oxygen.)
Prevention ● Heat meat thoroughly and do not eat raw meat. ● Prevent cross-contamination. (Keep raw meat and cooked meat separated.) ● Dry cooking equipment thoroughly after washing and sanitizing.
This bacteria is common to mucous membranes in humans and animals. Illness usually occurs when uncooked foods such as sandwiches, salads and desserts are prepared by somebody with a skin infection allowing Staphylococcus Aureus to secrete a toxin into the food. Symptoms typically include nausea, vomiting, diarrhea and abdominal pain.
Habitat ● Widely distributed in the wounds of humans and animals (especially festering wounds), throat and nasal cavities.
Infectious Foods ● Sushi, box lunches, sandwiches, cakes and other pre-made foods. Contamination occurs from a cook's hands.
Characteristics ● Multiplies in contaminated foods releasing enterotoxin which is resistant to heat, dry conditions, gastric acid and digestive enzymes.
Incubation ● 30 minutes - 6 hours
Symptoms ● Severe nausea, vomiting, diarrhea, and abdominal pain.
Prevention ● People with rough hands or wounds (especially festering wounds) to avoid contacting with food or utensils directly. ● Avoid using leftover food. ● Prevent cross contamination. (Wash and sanitize hands.)
Clostridium perfringens is widely found in nature such as water, soil and even the human intestines. Food poisoning usually occurs when stewed foods such as sauces, curries or soups are cooked in a large quantizes leading outbreaks. Symptoms include abdominal pain and diarrhea for less than 24 hours. Fever and vomiting are not common.
Habitat ● Widely distributed in nature such as soil, water and human feces. Cattle, poultry and fish are regular carriers.
Infectious Foods ● Stewed food cooked with contaminated meat or seafood. ● Foods such as curries or soups, which are cooked in large quantities. Proliferates at the bottom of the pot causing widespread food poisoning.
Characteristics ● Anaerobic (Proliferates in an environment with no oxygen.) ● Has special spore structure that can not be killed even when cooked for 6 hours. ● One case affects a large number of people leading outbreaks.
Incubation ● 6 - 18 hours
Symptoms ● Watery stool and slight abdominal pain.
Prevention ● Keep stirring while cooking soups or curries to introduce oxygen and suppress growth of C.Perfringens. ● Try to finish food as soon as possible and avoid leaving food at room temperature. ● Divide leftovers into small portions and immediately cool down and store in the refrigerator. (Below 10℃ (50°F) or over 55℃ (131°F).)
Vibrio Parahaemolyticus is found in specific saltwater environments and infects from improperly cooked seafoods such as fish and shellfish. Because of its environmental requirements, it is often easy to wash or kill, but infection rates are increased when food is consumed raw. Symptoms include diarrhea, pain, nausea and vomiting for 2 to 3 days.
Habitat ● Sea water, seafood such as fish and shellfish.
Infectious Foods ● Raw saltwater fish, shellfish and related products. ● Cross-contaminated foods. (Often salt preserved foods.)
Characteristics ● Halophilic, an environment with around 3% salinity can cause rapid growth. ● Weak activity in fresh water. ● Proliferates rapidly in a short time.
Incubation ● 8 - 24 hours
Symptoms ● Diarrhea, abdominal pain (around the navel), nausea, vomiting and fever.
Prevention ● Keep seafood chilled until cooking. Bacterial activity becomes low at temperatures below 4℃ (39.2°F). ● Wash seafood thoroughly with fresh water even if it is fresh. ● Prevent cross contamination. (Especially direct and indirect contact of seafood and other foods must be avoided.)
Habitat ● Widely distributed in nature such as fresh water and soil.
Infectious Foods ● Rice, wheat and other grain based foods such as pasta, bread, rice, and noodles.
Characteristics ● Forms spores that are resistant to 90℃ (194°F) of heat for one hour. ● There are two types of food poisoning attacks: vomiting type and diarrhea type. Vomitting type produces toxins while multiplying in foods, especially rices and noodles. ● Most active around 30℃ (86°F). Proliferates rapidly in cooled cooked food.
Prevention ● Cook only necessary amount and eat soon after cooking. ● Eat leftovers as soon as possible. ● Store food at temperatures below 8℃ (46.4°F) or over 55℃ (131°F) when eaten within 4 hours.
Yersinia is found in nature such as in the intestines of pig, dogs, and cats. Food poisoning occurs as a result of eating contaminated meat, milk and dairy products. It can multiple at low temperatures such as in the refrigerator, but is sensitive to heat. Symptoms include fever, abdominal pain and diarrhea.
Habitat ● In the intestines of livestock (especially pigs), rats, dogs, and cats.
Infectious Foods ● Milk, dairy products, meat, ground water contaminated by livestock feces.
Characteristics ● Two types of Yersinia cause food poisoning. ● Psychrotrophic bacteria which can proliferate at temperatures below 4℃ (39.2°F). ● Weak against heat. Contamination can be prevented by heating foods.
Incubation ● 0.5 - 6 days (Yersinia Enterocolitica)
Symptoms ● Fever, sharp abdominal pain and diarrhea. Often seen in children from 2 to 3 years old.
Prevention ● Heat meat thoroughly and eat soon after cooking. ● Avoid storing raw meat in a refrigerator for a long time and keep in a freezer instead.
Clostridium botulinum is an anaerobic bacteria found in the soil, oceans and lakes. It produces a nerve toxin when it multiples. Food borne illness is caused when food, contaminated with the toxin, is eaten. Symptoms include nausea, vomiting, and dizziness. It can be fatal if left untreated.
Habitat ● Widely distributed in the soil as well as in oceans and lakes.
Infectious Foods ● Ham, sausage, vegetables, fruits, canned foods and vacuum-packed foods.
Characteristics ● Anaerobic (can proliferate without oxygen). ● Can produce neurotoxin in humans. ● Has a special spore structure that is resistant to heat.
Incubation ● 8 - 36 hours
Symptoms ● Weakness, tired feeling, dizziness, nausea, vomiting and constipation. (Delay in treatment may cause breathing difficulties and even death.)
Prevention ● Wash fresh ingredients thoroughly before use. (The neurotoxin can be destroyed in 30 minutes at 80℃ (176°F) and 1 minute at 100℃ (212°F). ● Avoid eating inflated canned or vacuum-packed foods. ● Do not feed honey to infants under 1 year old. (To prevent infant botulinum.)
Norovirus is a virus unique to the human large intestine, however food poisoning is often associated with consuming raw oysters or clams, which can become contaminated from human feces in the water. As few as 10 viruses can cause an infection resulting in nausea, vomiting, diarrhea and pain. Additional symptoms include possible fever, headache and muscle pain.
Habitat ● In the intestines of human, bivalve (two hinged shells) such as oysters.
Infectious Foods ● Oysters and shellfish. Cross-contaminated food through hands of food handlers.
Characteristics ● Only thrives in the intestines of human. ● Only a few viruses can cause infection with high incident rate. ● Immunity from a previous infection is temporary so people can be infected repeatedly. ● Food handlers' hands are often the cause of contamination in food poisoning cases. ● Infects through the consumption of contaminated foods as well as contact infection and airborne transmission.
Incubation ● 24 - 48 hours
Symptoms ● Nausea, vomiting, diarrhea, abdominal pain. Often accompanied by a slight fever.
Prevention ● A person who is suspected of having infection should not be involved in food preparation. ● Prevent cross contamination by washing and sanitizing hands thoroughly. ● Avoid eating raw shellfish, cook thoroughly. ● Sanitize contaminated environment.