Foodborne illness


Foodborne illness is any illness resulting from the contamination of food by pathogenic bacteria, viruses, or parasites, as well as prions, and toxins such as aflatoxins in peanuts, poisonous mushrooms, and various species of beans that have not been boiled for at least 10 minutes. While contaminants directly cause some symptoms, many effects of foodborne illness result from the body's immune response to these agents, which can vary significantly between individuals and populations based on prior exposure.
Symptoms vary depending on the cause. They often include vomiting, fever, aches, and diarrhea. Bouts of vomiting can be repeated with an extended delay in between. This is because even if infected food was eliminated from the stomach in the first bout, microbes, like bacteria, can pass through the stomach into the intestine and begin to multiply. Some types of microbes stay in the intestine.
For contaminants requiring an incubation period, symptoms may not manifest for hours to days, depending on the cause and on the quantity of consumption. Longer incubation periods tend to cause those affected to not associate the symptoms with the item consumed, so they may misattribute the symptoms to gastroenteritis, for example.
In low- and middle-income countries in 2010, foodborne disease were responsible for approximately 600 million illnesses and 420,000 deaths, along with an economic loss estimated at US$110 billion annually.

Causes

Foodborne disease can be caused by a number of bacteria, such as Campylobacter jejuni, and chemicals, such as pesticides, medicines, and natural toxic substances, such as vomitoxin, poisonous mushrooms, or reef fish.
Foodborne illness usually arises from improper handling, preparation, or food storage. However, many cases result from the immune system's response to unfamiliar microbes rather than from direct microbial damage, explaining why local populations often tolerate food that sickens travelers.
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.

Bacteria

are common causes of foodborne illness. In 2000, the United Kingdom reported the individual bacteria involved as the following: Campylobacter jejuni 77.3%, Salmonella 20.9%, Escherichia coli O157:H7 1.4%, and all others less than 0.56%.
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. However, in some cases, such as Staphylococcal food poisoning, the onset of illness can be as soon as 30 minutes after ingesting contaminated food.
A 2022 study concluded that the practice of washing uncooked chicken actually increases the risk of pathogen transfer through the splashing of water droplets, with factors such as faucet height, flow type, and surface stiffness affecting the risk of cross-contamination.
The 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
  • Escherichia coli O157:H7 enterohemorrhagic which can cause hemolytic-uremic syndrome
Other common bacterial foodborne pathogens are:
  • Bacillus cereus
  • Escherichia coli, other virulence properties, such as enteroinvasive, enteropathogenic, enterotoxigenic, enteroaggregative
  • Listeria monocytogenes
  • Shigella spp.
  • Staphylococcus aureus
  • 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
  • ''Plesiomonas shigelloides''

    Emerging foodborne pathogens

  • Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria
Scandinavian outbreaks of Yersinia enterocolitica have recently increased to an annual basis, connected to the non-canonical contamination of pre-washed salad.

Preventing bacterial food poisoning

Governments have the primary public health mandate of ensuring safe food for all, however all actors in the food chain are responsible to ensure only safe food reaches the consumer, thus preventing foodborne illnesses. This is achieved through the implementation of strict hygiene rules and a public veterinary and phytosanitary service that monitors animal products throughout the food chain, from farming to delivery in shops and restaurants. This regulation includes:
  • traceability: the origin of the ingredients and where and when it has been processed must be known in the final product; in this way, the origin of the disease can be traced and resolved, and the final products can be removed from 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.
In August 2006, the United States Food and Drug Administration approved phage therapy which involves spraying meat with viruses that infect bacteria, and thus preventing infection. This has raised concerns because without mandatory labeling, consumers would not know that meat and poultry products have been treated with the spray.
At home, prevention mainly consists of good food safety practices. Many forms of bacterial poisoning can be prevented by cooking food sufficiently, and either eating it quickly or refrigerating it effectively. Many toxins, however, are not destroyed by heat treatment.
Techniques that help prevent food borne illness in the kitchen are hand washing, rinsing produce, preventing cross-contamination, proper storage, and maintaining cooking temperatures. In general, freezing or refrigerating prevents virtually all bacteria from growing, and heating food sufficiently kills parasites, viruses, and most bacteria. Bacteria grow most rapidly at the range of temperatures between, called the "danger zone". Storing food below or above the "danger zone" can effectively limit the production of toxins. For storing leftovers, the food must be put in shallow containers
for quick cooling and must be refrigerated within two hours. When food is reheated, it must reach an internal temperature of or until hot or steaming to kill bacteria.

Enterotoxins

s are potent compounds produced by various microorganisms that specifically target and damage the intestines, causing many of the most rapid and severe forms of food poisoning. Unlike bacterial infections that require live organisms to multiply in the gut, enterotoxins can cause illness even when the bacteria that produced them have been killed through cooking or other preservation methods.
Symptom onset varies with the toxin but may be rapid in onset, as in the case of enterotoxins of Staphylococcus aureus in which symptoms appear in one to six hours. This causes intense vomiting including or not including diarrhea, and staphylococcal enterotoxins 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.

Cultural adaptation and food safety

Traditional preservation methods like fermentation, sun-drying, and smoking have been used for centuries. These methods not only preserve food but also enhance nutritional value and can reduce foodborne illnesses by creating environments that inhibit harmful bacteria.
The notion that modern food safety standards are universally applicable is challenged by the effectiveness of these traditional methods. In cultures without access to modern refrigeration, traditional preservation techniques adapted to local climates and resources have proven effective in preventing spoilage and illness. Community knowledge and social practices can be as critical as technical standards in ensuring food safety, differing significantly from the regulatory focus in Western systems.

Mycotoxins and alimentary mycotoxicoses

The term alimentary mycotoxicosis refers to the effect of poisoning by mycotoxins through food consumption. The term mycotoxin is usually reserved for the toxic chemical compounds naturally produced by fungi that readily colonize crops under specific temperature and moisture conditions.
Mycotoxins can have severe effects on human and animal health. For example, an outbreak which occurred in the UK during 1960 caused the death of 100,000 turkeys which had consumed aflatoxin-contaminated peanut meal. In the USSR in World War II, 5,000 people died due to alimentary toxic aleukia. In Kenya, mycotoxins led to the death of 125 people in 2004, after consumption of contaminated grain.
In animals, mycotoxicosis targets organ systems such as the liver and digestive system. Other effects can include reduced productivity and suppression of the immune system, thus pre-disposing the animals to other secondary infections.
The common foodborne Mycotoxins include:
  • Aflatoxins – originating from Aspergillus parasiticus and Aspergillus flavus. They are frequently found in tree nuts, peanuts, maize, sorghum and other oilseeds, including corn and cottonseeds. The pronounced forms of aflatoxins are those of B1, B2, G1, and G2, amongst which Aflatoxin B1 predominantly targets the liver, which will result in necrosis, cirrhosis, and carcinoma. Other forms of aflatoxins exist as metabolites such as Aflatoxin M1. In the US, the acceptable level of total aflatoxins in foods is less than 20 μg/kg, except for Aflatoxin M1 in milk, which should be less than 0.5 μg/kg. The European union has more stringent standards, set at 10 μg/kg in cereals and cereal products. These references are also adopted in other countries.
  • Altertoxins – are those of alternariol, alternariol methyl ether, altenuene, altertoxin-1, tenuazonic acid, and radicinin, originating from Alternaria spp. Some of the toxins can be present in sorghum, ragi, wheat and tomatoes. Some research has shown that the toxins can be easily cross-contaminated between grain commodities, suggesting that manufacturing and storage of grain commodities is a critical practice.
  • Citrinin
  • Citreoviridin
  • Cyclopiazonic acid
  • Cytochalasins
  • Ergot alkaloids / ergopeptine alkaloids – ergotamine
  • Fumonisins – Crop corn can be easily contaminated by the fungi Fusarium moniliforme, and its fumonisin B1 will cause leukoencephalomalacia in horses, pulmonary edema syndrome in pigs, liver cancer in rats and esophageal cancer in humans. For human and animal health, both the FDA and the EC have regulated the content levels of toxins in food and animal feed.
  • Fusaric acid
  • Fusarochromanone
  • Kojic acid
  • Lolitrem alkaloids
  • Moniliformin
  • 3-Nitropropionic acid
  • Nivalenol
  • Ochratoxins – In Australia, The Limit of Reporting level for ochratoxin A analyses in 20th Australian Total Diet Survey was 1 μg/kg, whereas the EC restricts the content of OTA to 5 μg/kg in cereal commodities, 3 μg/kg in processed products and 10 μg/kg in dried vine fruits.
  • Oosporeine
  • Patulin – Currently, this toxin has been advisably regulated on fruit products. The EC and the FDA have limited it to under 50 μg/kg for fruit juice and fruit nectar, while limits of 25 μg/kg for solid-contained fruit products and 10 μg/kg for baby foods were specified by the EC.
  • Phomopsins
  • Sporidesmin A
  • Sterigmatocystin
  • Tremorgenic mycotoxins – Five of them have been reported to be associated with molds found in fermented meats. These are fumitremorgen B, paxilline, penitrem A, verrucosidin, and verruculogen.
  • Trichothecenes – sourced from Cephalosporium, Fusarium, Myrothecium, Stachybotrys, and Trichoderma. The toxins are usually found in molded maize, wheat, corn, peanuts and rice, or animal feed of hay and straw. Four trichothecenes, T-2 toxin, HT-2 toxin, diacetoxyscirpenol, and deoxynivalenol have been most commonly encountered by humans and animals. The consequences of oral intake of, or dermal exposure to, the toxins will result in alimentary toxic aleukia, neutropenia, aplastic anemia, thrombocytopenia and/or skin irritation. In 1993, the FDA issued a document for the content limits of DON in food and animal feed at an advisory level. In 2003, US published a patent that is very promising for farmers to produce a trichothecene-resistant crop.
  • Zearalenone
  • Zearalenols