Ch. 11 environmental health

Foodborne Infection

A foodborne disease is when a person eats food containing harmful microorganisms, which then grow in the intestinal tract and cause illness.

Four Major Categories of Food Hazards

Biological Physical (e.g., stone, glass, metal) Chemical Nutritional

Examples of Marine Toxins

Ciguatoxin Scombroid toxin Paralytic shellfish poison Puffer fish toxin

Listeria monocytogenes

Commonly found in soil and water Animals can be asymptomatic and carry bacteria (meat and dairy products) Can live for years in processing factories Dole salads, January 2016 Hot dogs, deli meats

viral agents that cause foodborne disease are

Hepatitis A, norovirus, and rotavirus

Staphyloccus aureus

Humans and animals are reservoirs. Present in the nose and in skin lesions Elaborates a toxin that is resistant to high temperatures Causes a foodborne intoxication with rapid onset Ham is a frequent vehicle

Food Additives

Intentional (direct) additives are added to foods in order to improve their quality. Incidental (indirect) additives may be present in foods as a result of unintentional contamination during packaging, storage, and handling. Malicious additives include substances such as poisons that saboteurs introduce into foods for various reasons.

Bacterial Agents

Salmonella, Clostridium botulinum, Staphylococcus aureus, and Clostridium perfringens

Toxin-mediated Infection

A toxin-mediated infection is when a person eats food containing harmful bacteria. While in the intestinal tract, the bacteria produce toxins that cause illness. Some bacteria cause toxin-mediated infection. Viruses and parasites do not cause a toxin-mediated infection. The foodborne bacteria that cause toxin-mediated infection are: Shigella spp. And Shiga toxin-producing Escherichia coli

Symptoms of Salmonellosis

Acute symptoms (onset time 6-48 hours) Nausea Vomiting Abdominal cramps Diarrhea Fever Headache Chronic symptoms May include arthritic-like symptoms that occur 3-4 weeks after an acute infection

Clostridium botulinum

Causes the foodborne disease botulism, a form of foodborne intoxication. Grows in an anaerobic (oxygen-free) environment and produces a potent toxin (a neurotoxin) that affects the nervous system. Canned vegetables, honey Botox: paralyzes facial muscles

The Global Increase in Foodborne Illness

Changes in agricultural and food processing methods Globalization of food distribution Social and behavioral changes among the human population

Foodborne Illnesses Caused by Viral Agents: Hepatitis A

Foods that are associated commonly with HAV outbreaks include fruits, sandwiches made with cold cuts, dairy products, vegetables, and shellfish. Common mode for contamination of foods is by HAV-infected workers in food processing plants and restaurants. Of the 23,000 cases of hepatitis A reported in the U.S. annually, about 7% are believed to be food- or waterborne.

Effects of Infection with C. Perfringens

Intense abdominal cramps Diarrhea Onset 8-22 hours after consumption of incriminated food Duration Approximately 24 hours. Mild symptoms may last for 1 or 2 weeks.

Safe holding temperature

Keep foods above 140˚F for hot foods and below 40˚F for foods that are kept in cold storage. The range between 40˚F and 140˚F is the danger zone

Shiga Toxin Producing E. coli (STEC)

Note that many E. coli strains reside harmlessly in the intestinal tract. Shiga toxin is extremely poisonous compound secreted by E.coli Causes hemorrhagic and necrotic colitis

Sources of Salmonella

Occur widely in wild and domestic animal reservoirs Animals that are used for human consumption—poultry, swine, cattle—may harbor Salmonella. Pet animals such as cats, dogs, and turtles also can be reservoirs for Salmonella. Some animals and birds are chronic carriers of the bacteria

Effects of Botulism

Onset of symptoms in foodborne botulism is usually 18 to 36 hours after ingestion of the food containing the toxin, although cases have varied from 4 hours to 8 days." Early signs: Marked lassitude Weakness and vertigo Double vision Progressive difficulty in speaking and swallowing Difficulty in breathing Weakness of other muscles Abdominal distention Constipation

Prions

Prions are regarded as the cause of bovine spongiform encephalopathy (BSE), a neurological disease in cattle. The course of BSE is progressive, ultimately fatal, and is potentially transmissible among cattle.

foodborne bacteria

Salmonella spp., Listeria monocytogenes, Campylobacter jejuni, Vibrio parahaemolyticus, Vibrio vulnificus, and Yersinia enterocolitica.

Effects of Infection with Tapeworms

Symptoms of taeniasis usually are limited to mild abdominal distress. One of the main symptoms is the passage of the proglottids (the section of the worm that contains eggs) of T. saginata and T. solium in stools

Tapeworms

Taeniasis is a parasitic disease caused by tapeworms. One form is caused by the beef tapeworm (Taenia saginata) and the other by the pork tapeworm (Taenia solium). These organisms may induce human illness following the consumption of raw or undercooked infected beef or pork.

Clostridium perfringens

The CDC estimates that about 10,000 cases occur each year in the U.S. C. perfringens is anaerobic, rod-shaped, and forms spores. Occurs commonly in the environment (e.g., in soil and sediments), especially in those areas contaminated with feces Also found in the intestines of humans and animals

Intentional Additives: Preservatives

The function of preservatives is to arrest the proliferation of microbes such as bacteria, yeasts, and molds in foods. Antioxidants prevent fatty foods from acquiring a rancid taste; they also prevent some foods from turning brown and reduce the loss of vitamins. Among the antimicrobial preservatives are nitrates (e.g., sodium nitrate), BHA and BHT, disodium EDTA, sulfites, proprionates, and parabens.

Salmonella

The infection is called salmonellosis. Salmonella bacteria are: Rod-shaped Motile Gram-negative Non-sporeforming The most common serotypes in U.S. are: Salmonella serotype Enteritidis Salmonella serotype Typhimurium

How are Salmonella Bacteria Transferred?

To environmental surfaces at work and at home (e.g., the kitchen) from raw meats, poultry, and seafood From animal feces From contaminated water and soil

Chemically Related Foodborne Hazards

Toxins Heavy metals Pesticides, herbicides, and fungicides Veterinary medicines in meat Additives used for various purposes Cleaning products

Norovirus

Transmitted easily within closed environments such as cruise ships May be brought on board by passengers who fall ill just before embarking on a cruise Crew members and ship-board environmental contamination may act as disease reservoirs.

foodborne parasites

Trichinella spiralis, Anisakis simplex, Giaria duodenalis, Toxoplasma gondii, Cryptosporidium parvum, and Cyclospora cayetanensis

Foodborne Illnesses Caused by Worms: Trichinosis

Trichinosis is a foodborne disease associated with eating meat that contains a nematode (also called a roundworm) from the genus Trichinella. The classic agent of trichinosis is Trichinella spiralis, which can be found in many carnivorous and omnivorous animals (e.g., pigs, bears, walruses, rodents, and cougars).

Norovirus Symptoms

Vomiting Diarrhea Dehydration Abdominal cramps These symptoms last from one to two days.

Foodborne Outbreak

the occurrence of a similar illness among two or more people which an investigation linked to consumption of a common meal or food items, except for botulism (one case is an outbreak)