Food safety notes

Definition: "Illnesses acquired by consumption of contaminated food."
- Frequently and inaccurately referred to as food poisoning.
Causes:
- Bacteria
- Viruses
- Toxins
Outbreak Definition: "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)."
Public Health Impact:
- Major cause of morbidity and mortality in the US and worldwide.
- Increased incidence in industrialized nations.
- Recognized as a public health problem.

Facts:
- Affects almost one-quarter of the population each year in the U.S.
- Causes an estimated 9,000 deaths annually.
- Incurs an economic cost of $5 billion annually.
Surveillance:
- The Centers for Disease Control and Prevention (CDC) maintains responsibility at the federal level.
- The CDC Foodborne Diseases Active Surveillance Network (FoodNet) operates an active system of frequent direct contact with clinical laboratory directors to identify new cases of foodborne illness.

Changes in:
- Agriculture and food processing methods.
- Globalization of food distribution.
- Social and behavioral changes among the human population.

Four Major Categories:
- Biological (e.g., bacteria, viruses)
- Physical (e.g., stone, glass, metal)
- Chemical (e.g., residues, toxins)
- Nutritional (e.g., excessive or deficient nutrients leading to disease)

Salmonella
- Causes salmonellosis.
- Common Serotypes in the U.S.:
- Salmonella serotype Enteritidis
- Salmonella serotype Typhimurium
- Characteristics:
- Rod shaped, motile, gram-negative, non-spore forming.
- Incidence:
- Estimated 1 million cases annually; causes approximately 380 deaths.
- Sources of Contamination:
- Wild and domestic animals (e.g., poultry, swine, cattle).
- Pet animals (e.g., cats, dogs).
- Environmental surfaces contaminated by raw meat, feces, contaminated water and soil.
- Symptom Onset:
- 6-72 hours after ingestion.
Clostridium botulinum
- Causes botulism (a form of foodborne intoxication).
- Produces a potent neurotoxin affecting the nervous system.
- Grows in anaerobic environments.
- Symptom Onset:
- 18–36 hours after ingestion (may vary from 4 hours to 8 days).
Clostridium perfringens
- Estimated 1 million cases annually in the U.S.
- Anaerobic, rod-shaped, spore-forming.
- Common in soil, intestines of humans and animals.
- Onset: About 16 hours after consumption.
Staphylococcus aureus
- Found in humans and animals (nose, throat, skin lesions).
- Produces a heat-resistant toxin.
- Common vehicle: ham; thrives in environments with high salt or sugar concentration.
Escherichia coli (E. coli O157:H7)
- Pathogenic strain causing hemorrhagic colitis and bloody diarrhea.
- Incidence: Wholesome, 73,000 cases and 61 deaths yearly linked to food.
- Key transmission source: undercooked hamburger meat.

Trichinosis
- Associated with nematodes from the genus Trichinella (e.g., Trichinella spiralis).
- Found in carnivorous and omnivorous animals (e.g., pigs, bears).
Tapeworms (Taeniasis)
- Caused by the beef tapeworm (Taenia saginata) or pork tapeworm (Taenia solium).
- Human illness occurs following consumption of raw or undercooked infected meats.

Hepatitis A
- Approx. 1,600 cases annually believed to be foodborne.
- Vaccine available but not required.
- Commonly transmitted through contamination of raw foods (e.g., shellfish, salads), often via fecal-oral route.
- Symptoms: vomiting, diarrhea, dehydration, abdominal cramps.
Norovirus
- Another significant viral agent causing foodborne illness.
Prions
- Cause bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob Disease (vCJD) in humans; linked to BSE exposure from contaminated food sources.

Toxins: Naturally occurring toxins (e.g., from seafood, mushrooms) may be associated with foodborne illness.
Heavy Metals: Can cause symptoms such as vomiting; high concentrations lead to acute symptoms within minutes to a few hours.

Contaminants leaching from food containers, lead in candy wrappers, and high arsenic levels found in poultry feed.
Certain fish species (e.g., shark, swordfish) may contain harmful mercury levels.

Antimicrobials used for disease prevention and growth enhancement in livestock (e.g., amoxicillin, penicillin).
Concerns include potential persistence in human food, contributing to antimicrobial resistance, and indirect toxicity.

Intentional (direct): Added to enhance food quality.
Incidental (indirect): Result from unintentional contamination.
Malicious additives: Poisons added intentionally for sabotage.
Preservatives: Headers such as nitrates and BHT; may present health concerns (e.g., carcinogenic potential due to nitrosamines).

Agencies:
- Food and Drug Administration (FDA) regulates food safety in general.
- USDA regulates meat and poultry safety.
Significant Regulations:
- Food & Drug Act 1906
- Federal Food, Drug, and Cosmetic Act 1938
- Miller Pesticide Amendments 1954
- Food Additives Amendment 1958 (Delaney Clause).
- Food Quality Protection Act 1996 (limits cancer cases linked to chemical exposure).

Risk Factors:
- Inadequate cooling, holding temperatures (top risk factor).
- Hot foods must be kept above 140°F and cold foods below 40°F, while anything between 40°F and 140°F is considered the danger zone.
Preventative Measures:
- Engage in thorough hand washing, avoid cross-contamination, cook foods thoroughly, store properly.
Irradiation:
- Safe method for destroying bacteria and pathogens in food, referred to as cold pasteurization.