Food Borne Illness or Food Poisoning
Foodborne illness (also foodborne disease and often referred to as food poisoning) is any illness resulting from the consumption of contaminated food, pathogenic bacteria, viruses, or parasites that contaminate food, as well as chemical or natural toxins such as poisonous mushrooms.
Symptoms vary depending on the cause. A few broad generalizations can be made, e.g.: The incubation period ranges from hours to days, depending on the cause and on how much was consumed.
The incubation period tends to cause sufferers to not associate the symptoms with the item consumed, and so to cause sufferers to attribute the symptoms to stomach flu for example.
Symptoms often include vomiting, fever, and aches, and may include diarrhea.
Bouts of vomiting can be repeated, with an extended delay in between, because even if infected food was eliminated from the stomach in the first bout, microbes (if applicable) can have passed through the stomach into the intestine, attached to the cells lining the intestinal walls, and begun to multiply there.
Some types of microbes stay in the intestine, some produce a toxin that is absorbed into the bloodstream, and some can directly invade deeper body tissues.
Foodborne illness usually arises from improper handling, preparation, or food storage. Good hygiene practices before, during, and after food preparation can reduce the chances of contracting an illness.
There is a consensus in the public health community that regular hand-washing is one of the most effective defenses against the spread of foodborne illness.
The action of monitoring food to ensure that it will not cause foodborne illness is known as food safety. Foodborne disease can also be caused by a large variety of toxins that affect the environment.
Foodborne illness can also be caused by pesticides or medicines in food and naturally toxic substances such as poisonous mushrooms or reef fish.
Bacteria are a common cause of foodborne illness. In the past, bacterial infections were thought to be more prevalent because few places had the capability to test for norovirus and no active surveillance was being done for this particular agent.
Toxins from bacterial infections are delayed because the bacteria need time to multiply.
As a result, symptoms associated with intoxication are usually not seen until 12–72 hours or more after eating contaminated food. Usually the symptoms are seen the day after the food has been ingested and digested completely.
However if the intoxication involves preformed toxins as is the case with Staphylococcal food poisoning, the symptoms appear within a few hours.
Most common bacterial foodborne pathogens are:
Campylobacter jejuni which can lead to secondary Guillain–Barré syndrome and periodontitis
Clostridium perfringens, the “cafeteria germ”
Salmonella spp. – its S. typhimurium infection is caused by consumption of eggs or poultry that are not adequately cooked or by other interactive human-animal pathogens
Salmonella
Escherichia coli O157:H7 enterohemorrhagic (EHEC) which can cause hemolytic-uremic syndrome
Other common bacterial foodborne pathogens are:
Bacillus cereus
Escherichia coli, other virulence properties, such as enteroinvasive (EIEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroaggregative (EAEC or EAgEC)
Listeria monocytogenes
Shigella spp.
Staphylococcus aureus
Staphylococcal enteritis
Streptococcus
Vibrio cholerae, including O1 and non-O1
Vibrio parahaemolyticus
Vibrio vulnificus
Yersinia enterocolitica and Yersinia pseudotuberculosis
Less common bacterial agents:
Brucella spp.
Corynebacterium ulcerans
Coxiella burnetii or Q fever
Plesiomonas shigelloides
Enterotoxins
In addition to disease caused by direct bacterial infection, some foodborne illnesses are caused by a enterotoxins (an exotoxin targeting the intestines). Enterotoxins can produce illness even when the microbes that produced them have been killed.
Symptom appearance varies with the toxin but may be rapid on-set, as in the case of enterotoxins of Staphylococcus aureus in which symptoms appear in 1–6 hours.
This causes intense vomiting including or not including diarrhea (resulting in staphylococcal enteritis), and staphylococcal enterotoxins (most commonly Staphylococcal Enterotoxin A but also including Staphylococcal Enterotoxin B) are the most commonly reported enterotoxins although cases of poisoning are likely underestimated.
It occurs mainly in cooked and processed foods due to competition with other biota in raw foods, and humans are the main cause of contamination as a substantial percentage of humans are persistent carriers of S. aureus.
The CDC has estimated about 240,000 cases per year in the United States.
Clostridium botulinum
Clostridium perfringens
Bacillus cereus
The rare but potentially deadly disease botulism occurs when the anaerobic bacterium Clostridium botulinum grows in improperly canned low-acid foods and produces botulin, a powerful paralytic toxin.
Pseudoalteromonas tetraodonis, certain species of Pseudomonas and Vibrio, and some other bacteria, produce the lethal tetrodotoxin, which is present in the tissues of some living animal species rather than being a product of decomposition.
Emerging foodborne pathogens
Many foodborne illnesses remain poorly understood. Approximately 99.9% percent of outbreaks are caused by unknown sources.
Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria
Prevention is mainly the role of the state, through the definition of strict rules of hygiene and a public services of veterinary surveying of animal products in the food chain, from farming to the transformation industry and delivery (shops and restaurants).
This regulation includes:
traceability: in a final product, it must be possible to know the origin of the ingredients (originating farm, identification of the harvesting or of the animal) and where and when it was processed; the origin of the illness can thus be tracked and solved (and possibly penalized), and the final products can be removed from the sale if a problem is detected; enforcement of hygiene procedures such as HACCP and the “cold chain”; power of control and of law enforcement of veterinarians.
At home, prevention mainly consists of good food safety practices.
Many forms of bacterial poisoning can be prevented even if food is contaminated by cooking it sufficiently, and either eating it quickly or refrigerating it effectively.
Many toxins, however, are not destroyed by heat treatment.
