Access to safe and healthy food is key to lasting life and promoting good health. Unsafe food containing harmful bacteria, viruses, parasites or chemical substances can cause more than 200 different diseases, ranging from diarrhea to cancers. Around the world, an estimated 600 million, almost 1 in 10 people, fall ill after eating contaminated food each year, resulting in 420,000 deaths. (World Health Organization, ).

Food Borne Illnesses

Campylobacter

Basic Information

Campylobacter is 1 of 4 key global causes of diarrheal diseases. It is the most common bacterial cause of human gastroenteritis in the world. Campylobacter is common in food animals such as poultry, cattle, pigs, ostriches, and sheep; and in pets, including cats and dogs. The bacteria have also been found in shellfish. Campylobacteriosis is a zoonotic disease transmitted to humans from animals or animal products. Most often, meat is contaminated by Campylobacter from feces during slaughtering (World Health Organization, 2020). People can get Campylobacter infection by eating raw or undercooked poultry or eating something that touched it. They can also get it from eating other foods, including seafood, meat, and produce, by contact with animals, and by drinking untreated water (CDC, 2021a). Contaminated ice is also a source of infection (World Health Organization, 2020). Campylobacter infection is common with people who travel abroad. About one in five cases are associated with international travel (CDC, 2021a).

Symptoms

Campylobacter infections are generally mild, but can be deadly among very young children, elderly, and immunosuppressed individuals. The beginning of disease symptoms usually occurs 2–5 days after infection with the bacteria but can range from 1–10 days. The most common clinical symptoms of Campylobacter infections include diarrhea (frequently bloody), abdominal pain, fever, aching head, nausea, and/or vomiting. Neurological disorders such as Guillain-Barré syndrome, a polio-like form of paralysis in a small number of cases. Death from campylobacteriosis is rare and usually confined to very young children or elderly patients, or to those already suffering from another serious disease (World Health Organization, 2020).

Controls

Campylobacter species can be killed by heat and thoroughly cooking food. To prevent Campylobacter infections, make sure to follow basic food hygiene practices when preparing food. Bactericidal treatment, such as cooking, pasteurization or irradiation, is the only effective method of eliminating Campylobacter from poisoned contaminated foods (World Health Organization, 2020).

Salmonella

Basic Information

Salmonellosis is a disease caused by the bacteria Salmonella. Salmonella is 1 of 4 key global causes of diarrheal diseases. Salmonella bacteria are widely distributed in domestic and wild animals. They are common in food animals such as poultry, pigs, and cattle; and in pets, including cats, dogs, birds, and reptiles such as turtles. Salmonellosis in humans is generally contracted by eating contaminated food of animal origin (mainly eggs, meat, poultry, and milk), although other foods, including green vegetables can be contaminated by manure used as fertilizer. Person-to-person transmission can also occur through the fecal-oral route. Human cases also occur where individuals have contact with sick infected animals, including pets. These sick infected animals often do not show signs of disease (World Health Organization, 2020).

Symptoms

Salmonellosis is usually characterized by fever, abdominal pain, diarrhea, nausea, and sometimes vomiting. Symptoms of salmonellosis are usually mild and patients will make a recovery without specific treatment in most cases. However, in some cases, particularly in children and elderly patients, the associated dehydration can become severe and life-threatening. Symptoms generally occur 6–72 hours (usually 12–36 hours) after eating food contaminated with Salmonella, and the illness lasts 2–7 days (World Health Organization, 2020).

Controls

Prevention requires control measures at all stages of the food chain, from agricultural production, to processing, manufacturing and preparation of foods in both commercial establishments and at home. Basic food health hygiene practices, such as "cook thoroughly," are also recommended as a preventive measure against salmonellosis. The contact between young children and pet animals that may be carrying salmonella (such as cats, dogs, and turtles) needs careful supervision (World Health Organization, 2020).

Listeriosis

Basic Information

Foodborne listeriosis is one of the most serious and severe foodborne diseases. It is caused by the bacteria Listeria monocytogenes (L. Monocytogenes). It is a relatively rare disease with 0.1–10 cases per one million people per year depending on the countries and regions of the world. Although the number of cases of listeriosis is small, the high rate of death associated with this infection makes it a significant public health concern. Different from many other common foodborne diseases causing bacteria, L. monocytogenes can survive and multiply at low temperatures usually found in refrigerators. Eating poisoned contaminated food with high numbers of L. monocytogenes is the main route of infection. Infection can also be transmitted between humans, notably from pregnant women to unborn babies. L. monocytogenes are everywhere in nature and found in soil, water, and animal digestive tracts. Vegetables may be contaminated through soil or the use of manure as fertilizer. In past outbreaks, foods involved included ready-to-eat meat products, such as hotdogs, meat spreads, smoked salmon, and raw meat sausages, as well as dairy products (including soft cheeses, unpasteurized milk, and ice cream) and prepared salads (including coleslaw and bean sprouts) as well as fresh vegetables and fruits (World Health Organization, 2018c).

Symptoms

There are two main types of listeriosis: a non-invasive form and an invasive form.

Non-invasive listeriosis is a mild form of the disease affecting mainly otherwise healthy people. Symptoms include diarrhea, fever, aching head, and myalgia (muscle pain). The incubation period is short (a few days). Outbreaks of this disease have generally involved eating foods containing high amounts of L. monocytogenes. Invasive listeriosis is a more severe form of the disease and affects certain high-risk groups of the population. These include pregnant women, patients undergoing treatment for cancer, AIDS, organ transplants, and elderly people and babies. This form of disease is characterized by severe symptoms and a high death rate (20%–30%). The symptoms include fever, myalgia (muscle pain), septicemia, and meningitis. The incubation period is usually 1–2 weeks but can vary between a few days and up to 90 days. Pregnant women are about 20 times more likely to contract listeriosis than other healthy adults. It can result in miscarriage or stillbirth. Newborns may also have low birth weight, septicemia, and meningitis (World Health Organization, 2018c).

Controls

The control of L. monocytogenes is required at all stages in the food chain and an integrated approach is needed to prevent the multiplication of this bacteria in the final food product. The challenges for controlling L. monocytogenes are considerable given its nature to be everywhere and high resistance to common preservative methods such as the use of salt, smoke or acid. Guidance on the prevention of listeriosis is like guidance used to help prevent other foodborne illnesses. L. monocytogenes in food is killed by pasteurization and cooking. It is important to respect the shelf-life and storage temperature written on labels of ready-to-eat foods to ensure that bacteria potentially present in these foods does not multiply to dangerously high numbers (World Health Organization, 2018c).

Escherichia Coli (E. Coli)

Basic Information

E. Coli is a bacterium that is commonly found in the lower intestine of warm-blooded organisms. Most E .coli strains are harmless, but some can cause serious food poisoning. Shiga toxin-producing E. coli O157:H7 is a bacterium that can cause severe foodborne disease. Primary sources of outbreaks are raw or undercooked ground meat products, raw milk, and fecal poisoning contamination of vegetables. The reservoir of this pathogen appears to be mainly cattle but can include pigs, horses, rabbits, dogs, cats, and birds (such as chickens and turkeys). E. coli O157:H7 is transmitted to humans primarily through eating contaminated foods, such as raw or undercooked ground meat products and raw milk. Fecal poisoning, contamination of water and other foods, as well as cross-contamination during food preparation (with beef and other meat products, poisoned contaminated surfaces and kitchen supplies), will also lead to infection (World Health Organization, 2018b).

Symptoms

In most cases, the illness is self-limiting, but it may lead to a life-threatening disease including hemolytic uremic syndrome (HUS), especially in young children and the elderly. Symptoms include abdominal cramps and diarrhea that may in some cases progress to bloody diarrhea. Fever and vomiting may also occur. The incubation period can range from three to eight days, with a median of 3–4 days. Most patients recover within 10 days, but in a small proportion of patients (particularly young children and the elderly), the infection may lead to a life-threatening disease, such as hemolytic uremic syndrome (HUS). HUS is characterized by acute renal failure, hemolytic anemia, and thrombocytopenia (low blood platelets) (World Health Organization, 2018b).

Controls

E. coli is heat sensitive. In preparing food at home, be sure to follow basic food hygiene practices such as "cook thoroughly." The only effective method of eliminating it from foods is to introduce a bactericidal treatment, such as cooking, pasteurization or irradiation. Education in hygienic handling of foods for workers at farms and those involved in the food production is essential to keep microbiological contamination to a minimum. Washing hands regularly, particularly before food preparation or eating and after toilet contact, is highly recommended; especially for people who take care of small children, the elderly, or immunocompromised individuals. Screening the animals pre-slaughter and hygienic slaughtering practices reduce contamination of carcasses by feces but do not guarantee the absence of it. A few infections have been caused by contact with recreational water. Therefore, it is also important to protect such water areas, as well as drinking-water sources, from animal waste (World Health Organization, 2018b).

Botulism

Basic Information

Clostridium botulinum is a bacterium that produces dangerous toxins (botulinum toxins) under low-oxygen conditions. Botulinum toxins are one of the deadliest substances known. Although rare, it can be deadly if not diagnosed rapidly and treated with antitoxin. Homemade, canned, preserved, or fermented foodstuffs are a common source of foodborne botulism and their preparation requires extra caution. Person to person transmission of botulism does not occur. Spores produced by the bacteria Clostridium botulinum are heat-resistant and exist widely in the environment, and in the absence of oxygen they germinate, grow and then excrete toxins. The growth of the bacteria and the creation of toxins occur in products with low oxygen content. This happens most often in lightly preserved foods, and in inadequately processed, home-canned or home-bottled foods. The botulinum toxin has been found in a variety of foods, including low acid preserved vegetables, such as green beans, spinach, mushrooms, and beets; fish, including canned tuna, fermented, salted, and smoked fish; and meat products, such as ham and sausage. Though spores of C. botulinum are heat-resistant, the poison toxin produced by bacteria growing out of the spores under anaerobic conditions is destroyed by boiling (for example, at internal temperature greater than 85 °C for five minutes) (World Health Organization, 2018a).

There are four types of human botulism that include foodborne botulism, infant botulism, wound botulism, and inhalation botulism. Infant botulism occurs mostly in babies under six months of age. It occurs when C. botulinum spores from eaten food germinate into colonies of bacteria in the gut and release toxins. In most adults and children older than about six months, this would not happen because natural defenses in intestines that develop over time prevent germination and growth of the bacterium. Although there are several possible sources of infection for infant botulism, spore-contaminated honey has been associated with infant botulism. Parents and others caring for children are therefore warned not to feed honey to the babies before the age of one year (World Health Organization, 2018a).

Wound botulism is rare and occurs when the spores get into an open wound and can reproduce in an anaerobic environment (World Health Organization, 2018a).

Inhalation botulism is rare and does not occur naturally; for example, it is associated with accidental or intentional events (such as bioterrorism) which result in release of the toxins in aerosols (World Health Organization, 2018a).

The bacterium C. botulinum is the same bacterium that is used to produce Botox, a pharmaceutical product predominantly injected for clinical and cosmetic use. Botox treatments employ the purified and heavily diluted botulinum neurotoxin type A (World Health Organization, 2018a).

Symptoms

Botulinum toxins are neurotoxic and block nerve functions and can lead to respiratory and muscular paralysis. Foodborne botulism is characterized by descending, flaccid paralysis that can cause respiratory failure. Early symptoms include marked tiredness, weakness, and vertigo, usually followed by blurred vision, dry mouth, and difficulty in swallowing and speaking. Vomiting, diarrhea, constipation, and abdominal swelling may also occur. The disease can progress to weakness in the neck and arms, after which the respiratory muscles and muscles of the lower body are affected. There is no fever and no loss of consciousness. The disease can be deadly in 5–10% of cases. The symptoms are not caused by the bacterium itself, but by the toxin produced by the bacterium. Symptoms usually appear within 12 - 36 hours (within a minimum and maximum range of 4 hours to 8 days) after exposure. Infant botulism symptoms include constipation, loss of appetite, weakness, an altered cry, and a loss of head control (World Health Organization, 2018a).

Controls

Prevention of foodborne botulism is based on good practice in food preparation particularly during heating, and hygiene. Foodborne botulism may be prevented by the inactivation of the bacterium and its spores in heat-sterilized or canned products or by inhibiting bacterial growth and poison toxin production in other products. The vegetative forms of bacteria can be destroyed by boiling, but the spores can remain viable for several hours even after boiling. However, the spores can be killed by very high temperature treatments such as commercial canning. Commercial heat pasteurization (including vacuum packed pasteurized products and hot smoked products) may not be sufficient to kill all spores; therefore, the safety of these products must be based on preventing bacterial growth and poison toxin production. Refrigeration temperatures combined with salt content and/or acidic conditions will prevent the growth of the bacteria and creation of toxins (World Health Organization, 2018a).

Norovirus

Basic Information

Norovirus is the leading cause of illness and outbreaks from contaminated food in the United States. Most of these outbreaks occur in food service settings like restaurants. Sick food workers are frequently the source of outbreaks, often by touching ready-to-eat foods, such as raw fruits and vegetables, with their bare hands before serving them. However, any food served raw or handled after being cooked can become contaminated with norovirus. Norovirus often gets attention for outbreaks on cruise ships, but Norovirus is very contagious, and outbreaks can occur anywhere people gather, or food is served. People infected with norovirus are very contagious. While sick, they spread billions of tiny viral particles in their stool and vomit (CDC, 2021b). It takes a very small amount, as few as 18 viral particles, to make another person sick. People of all ages can get sick if they are exposed to a tiny amount of stool or vomit from a sick person (CDC, 2019). You can get norovirus illness many times in your life because there are many different types of noroviruses. Infection with one type of norovirus may not protect you against other types. It is possible to develop immunity to (protection against) specific types. However, it is not known exactly how long immunity lasts. Norovirus is sometimes called the stomach flu or stomach bug. However, norovirus illness is not related to the flu which is caused by influenza virus (CDC, 2021b).

Symptoms

The most common symptoms of norovirus are diarrhea, vomiting, nausea, and stomach pain. Other symptoms may include fever, aching head, and body aches. A person usually develops symptoms 12–48 hours after being exposed to norovirus. Most people with norovirus illness get better within 1–3 days. Norovirus is the most common cause of vomiting and diarrhea, and foodborne illness (CDC, 2021b).

Controls

You can help protect yourself and others from norovirus by washing your hands thoroughly with soap and water, especially after using the toilet or changing diapers. Wash your hands also before eating, preparing, or handling food, and before giving yourself or someone else medicine. You can use hand sanitizers in addition to hand washing, but you should not use hand sanitizer instead of washing your hands with warm water and soap. Washing hands is always best. Hand sanitizers aren’t as effective at removing norovirus particles as washing hands with water and soap. Carefully wash fruits and vegetables before preparing and eating them. After someone vomits or has diarrhea, always thoroughly clean and disinfect the entire area immediately. Wipe the area with paper towels, then disinfect the area using a bleach-based household cleaner. If using a chlorine bleach solution use a concentration of 1000–5000 ppm (5–25 tablespoons of bleach per gallon of water). Leave bleach on the affected area for at least five minutes, then clean the entire area again with soap and hot water (CDC, 2021b).

Food Safety Practices

The WHO recommends the following as keys to safe food practices for anyone handling and preparing food (World Health Organization, 2022).

Keep Clean

• Wash hands before handling food and often during food preparation and after going to the toilet.
• Wash and clean sanitize all surfaces and equipment used for food preparation.
• Protect kitchen areas and food from insects, pests, and other animals.

Separate Raw and Cooked

• Separate raw meat, poultry, and seafood from other foods.
• Use separate equipment and utensils, such as knives and cutting boards, for handling raw foods.
• Store food in containers to avoid contact between raw and prepared foods.

Cook Thoroughly:

• Cook food thoroughly, especially meat, poultry, eggs, and seafood.
• Bring foods like soups and stews to boiling, make sure that juices are clear, not pink.
• When possible, use a thermometer to ensure proper temperature.
• Thoroughly reheat cooked food.

Keep Food at Safe Temperatures

• Do not leave cooked food at room temperature for more than two hours.
• Quickly refrigerate all cooked and perishable food.
• Keep cooked food hot until serving.
• Do not store food too long, even in the refrigerator.
• Do not thaw frozen food at room temperature.

Use Safe Water and Raw Materials

• Use safe water or treat it to make it safe.
• Select fresh and healthy foods.
• Choose foods processed for safety, such as pasteurized milk.
• Wash fruits and vegetables, especially if eaten raw.
• Do not use food beyond its expiry date.

Practice Good Personal Hygiene

• Wash and dry hands with a clean, dry towel after toilet use, putting a diaper on a child, and contact with animals.
• Change clothes and bathe regularly.
• Cover cuts and wounds.
• Use a toilet or latrine to urinate or defecate.

References

CDC. (2019). Preventing Norovirus Outbreaks. Retrieved 29 December 2022, from https://books.byui.edu/-DcXN

CDC. (2021a). Campylobacter (Campylobacteriosis). Retrieved 29 December 2022, from https://books.byui.edu/-Ukdn

CDC. (2021b). Norovirus. Retrieved 29 December 2022, from https://books.byui.edu/-dmEN

World Health Organization.Health Topics - Food Safety. Retrieved 29 December 2022, from https://books.byui.edu/-Tio

World Health Organization. (2018a). Fact Sheet Botulism. Retrieved 29 December 2022, from https://books.byui.edu/-EQAL

World Health Organization. (2018b). Fact Sheet E. coli. Retrieved 29 December 2022, from https://books.byui.edu/-XawS

World Health Organization. (2018c). Fact Sheet Listeriosis. Retrieved 29 December 2022, from https://books.byui.edu/-GGwb

World Health Organization. (2020). Fact Sheet Campylobacter. Retrieved 29 December 2022, from https://books.byui.edu/-huvJ

World Health Organization. (2022). Compendium of WHO and other UN guidance on health and environment. ( No. WHO/HEP/ECH/EHD/22.01). Geneva: https://books.byui.edu/-YrjX