Env Hlt 100 - Ch. 11 Food Safety - Reading Notes PDF

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Chapter 11: Food Safety — Reading Notes: Week 6 Page 279 Introduction Foodborne Diseases - Illnesses acquired by consumption of contaminated food Frequently and inaccurately referred to as food poisoning Includes: Foodborne intoxications and food borne infections Foodborne Outbreak - The occurrence of similar illness among 2 or more people which an investigation linked to consumption of a common meal or food items EXCEPT for Botulism, one case is an outbreak Foodborne illness can be both acute and long term Some of the causes of acute Foodborne illness are microbiologic agents and toxic chemicals like pesticides and heavy metals Sources of food contamination are pollutants in water used to process foods chemicals used by the agriculture industry pollutants found in the air One of the important responsibilities of local and federal government agencies is to ensure the quality of foodstuffs Page 280 The Global Burden of Foodborne Illness From the global perspective, Foodborne illness is a major cause of morbidity and sometimes mortality Illnesses transmitted by foods can cause adverse birth outcome, chronic illness, disabilities Within the past few years, the incidence of Foodborne illnesses has increased in industrialized nations This increase has been attributed to changes in agricultural and food processing methods globalization in food distribution other social and behavioral changes among the human population Some estimates suggest that Foodborne illnesses affect almost 1/4 of the population each year in the US 9k deaths annually $5 billion in economic cost a year In recent years, the incidence of Foodborne illnesses in the US has tended to remain stable with recent declines in some conditions Surveillance of Foodborne Illness In the US, the CDC maintains responsibility at the federal level for surveillance

of Foodborne illness Passive Surveillance Systems rely on the reporting of cases of Foodborne illness by clinical laboratories to state health departments and ultimately to the CDC CDC Foodborne Diseases Active Surveillance Network (FoodNet) - An active system whereby public health officials maintain frequent direct contact with clinical laboratory directors to identify new cases of Foodborne illness The focus of the FoodNet program is diarrheal illnesses caused by emerging infectious disease agents Foodborne diseases caused by parasites Cyclospora Cryptosporidium Foodborne diseases caused by bacteria Campylobacter E. Coli O157:H7 Listeria monocytogenes Salmonella Shigella Vibrio associated with consumption of uncooked oysters taken from contaminated waters of the bacteria The Burden of Illness Period - Describes how reporting of Foodborne disease takes place shows the chain of events that must occur for an episode of illness in the population to be registered in surveillance Page 282 Categories of Food Hazards The BIG 3 categories of food hazards are biological, chemical, physical Nutritional Hazards - Those hazards associated with the presence of nutrients and other food constituents in excessive or deficient amounts that lead to disease Food hazards may be introduced when foods are harvested, processed, shipped, stored Common Microbial Agents of Foodborne Illness Emerging Foodborne Disease Pathogen - A type of microbial agent increasingly causing Foodborne infections A subset of agents from the general category of emerging infectious disease agents which cause emerging infections Examples of emerging infections cause by emerging Foodborne disease pathogens cholera, Rift Valley Fever, Lyme disease Emerging Foodborne disease pathogens include E. coli O157:H7, Campylobacter Jejuni, Listeria monocytogenes

Some of the microbial agents that cause Foodborne illness have adapted to changes in food production, causing their reemergence and the development of new pathogens A number of infectious agents tend to be associated with an increasing intensity of production and concentration of animals in limited spaces Microbial agents form 4 general classes Bacteria Parasites Viruses Other Page 283 Bacterial Agents Bacterial Pathogen examples Salmonella Clostridium botulinum Staphylococcus aureus Clostridium perfringens Bacteria - Unicellular organism the has characteristics shapes such as rod, spherical, spiral Bacteria can be moving (motile) propelled by flagella or nonmoving (nonmotile) Bacteria may be classified as Gram-positive or Gram-negative Foodborne infections should be differentiated from Foodborne intoxications Foodborne Infection - Induced by infectious agents such as some bacteria that cause Foodborne illness directly Foodborne Intoxications - Result from agents that do not cause infections directly but produce spores or toxins as they multiply in the food example is Staphylococcus aureus Salmonella Salmonella embodies approximately 2000 serotypes that can cause human illness Salmonella is the causative agent for the Foodborne infection salmonellosis Salmonella - A rod-shaped, motile, gram-negative, and non-sporeforming bacteria Page 284 Approximately 40 to 50k cases of salmonellosis are reported each year in the US about 500 deaths each year are caused by salmonella infections Salmonella is inwoon to occur widely in wild and domestic animal reservoirs poultry, swine, cattle, cats, dogs, birds Salmonella disease outbreak examples raw unpasteurized milk and products consumption cantaloupe from Mexico

Contaminated alfalfa sprouts Toasted Oats cereal Pasteurized milk Page 286 Several of the strains of salmonella have developed antibiotic resistance, making their treatment more difficult The development of antimicrobial-resistant Salmonella has been tied to the administration of antibiotics to animals consumed for food Clostridium Botulinum Clostridium botulinum causes the foodborne disease botulism Botulism is a form of foodborne intoxication Clostridium botulinum grows in an anaerobic (oxygen-free) environment and produces a neurotoxin that affects the nervous system, rod shaped Clostridium botulinum forms spores that are resistant to heat The form of the disease called infant botulism has been linked to consumption of honey by infants Page 287 Clostridium Perfringens Clostridium Perfringens causes Perfringens food poisoning intoxications Clostridium Perfringens is anerobic, rod shaped, and forms spores occurs commonly in the environment, especially areas contaminated with feces Page 288 Staphylococcus Aureus Staphylococcus aureus is a spherically shaped bacterium that causes foodborne intoxication with rapid onset Staphylococcus aureus can thrive in an environment that has heavy concentrations of salt or sugar e.g., ham Page 289 E. coli O157:H7 E. coli O157:H7 is one of 4 classes of E. coli that are designated enterovirulent Enterovirulent - causes inflammation of the intestines and the stomach The disease caused by E. coli O157:H7 is called hemorrhagic colitis because on of the symptoms of illness produced is bloody diarrhea For this reason, E. coli O157:H7 is referred to as an enterohemorrhagic

(EHEC) strain of E. coli Nonpathogenic strains of E. coli reside harmlessly in the intestinal tacts of animals and humans and are part of the normal bacterial flora Page 290 The organism E. coli O157:H7 is found in the intestines of healthy cattle, and may invade meat during the slaughter process In the US, 73k cases and 61 deaths occur annually due to E. coli O157:H7 Young children are particularly vulnerable to HUS caused by E. coli O157:H7 E. coli O157:H7 is associated with an outbreak involving hamburger strains Shigella Shigella bacteria, which are highly infectious, are the cause of shigellosis Page 291 The bacteria Shigella can be transmitted via the fecal-oral route through contaminated water and foods that are handled in an unsanitary manner Fewer than 10% of foodborne disease outbreaks in the US are believed to be caused by Shigella Campylobacter Jejuni Campylobacter Jejuni is responsible for an illness known as Campylobacteriosis Among the bacterial causes of forborne infections, Campylobacter Jejuni is among the most commonly reported agents About 2.1 to 2.4 million cases of Campylobacteriosis occur each year in the US Among the Campylobacter Jejuni-associated outbreaks, many are related to consumption of unpasteurized milk Unpasteurized milk can serve as a vehicle for many pathogens Page 294 Listeria Monocytogenes The illness listeriosis is caused by the bacterium Listeria Monocytogenes Listeria Monocytogenes is found in some domestic animals and several species of birds The bacterium Listeria Monocytogenes occurs widely in plant-related materials such as vegetables that may have been contaminated with sewage used as fertilizer Listeria Monocytogenes is associated with 2,500 cases of illness and 500 fatalities per year One outbreak associated with Listeria Monocytogenes was due to sliceable turkey del meat

Page 295 Worms Trichinella Trichinosis is a foodborne disease associated with eating meat that contains a nematode from the genus Trichinella The classic agent of Trichinosis is Trichinella Spiralis Trichinella Spiralis can be found in many carnivorous and omnivorous animals The disease may be transmitted from animals such s these to humans when meat that contains the cysts of Trichinella Spiralis has not been cooked adequately Following ingestion of meat that contains cysts, the larvae are released due to the action of stomach acids on the cysts For Trichinella Spiralis, the human host is a dead-end host meaning that the disease cannot spread to other humans Tapeworms Taeniasis is a parasitic disease caused by tapeworms Beef tapeworm is Taenia Saginata Pork tapeworm is Taenia Solium Page 296 These organisms may induce human illness following the consumption of raw or undercooked infected beef or pork Taenia Solium (Pork Tapeworm) can cause a serious condition termed cysticercosis in which the organism migrates to muscle or brain tissue and forms cysts Taenia Saginata (Beef Tapeworm) resides in human intestines Viral Agents Hepatitis A Virus (HAV) Hepatitis A Virus can be transmitted by both contaminated food and water Foods associated commonly with Hepatitis A Virus include Fruits, cold cut deli meat, vegetables, dairy products, shellfish Page 297 Norovirus Norovirus is transmitted easily within closed environments such as cruise ships Page 298 An outbreak of gastrointestinal illness is defined as having 3% or more of either passengers or crew reported with a gastrointestinal illness

Vessel Sanitation Program (VSP) - Ran by the CDC and aims to keep the risks of diarrheal disease outbreaks among passengers at a minimum Other Agents Prions Prions are hypothesized to be a modification of a normal protein Prion Protein - A pathogenic agent that can damage the central nervous system of cattle Infections with Prions are regarded as the cause of Bovine Spongiform Encephalopathy (BSE) Bovine Spongiform Encephalopathy (BSE) - Neurologic disease in cattle AKA mad cow disease Page 300 On Dec 23, 2003 the first known case of Bovine Spongiform Encephalopathy (BSE) was reported in the US as of 2010, 3 cases have been reported in the US BSE appears to be spread among cattle by feeds that contain rendered cattle products Human form of disease caused by consumption of Bovine Spongiform Encephalopathy (BSE) is a type of dementia called Variant Cruetzfeldt-Jakob Disease (vCJD) Page 301 Chemically Related Foodborne Hazards Foodborne hazards include toxins, heavy metals, pesticides, herbicides, fungicides, veterinary medicines in meat, additives Exposure to chemicals in food can result in acute and chronic toxic effects ranging from mild and reversible to serious and life threatening Effects include cancer birth defects, damage to the nervous, reproductive and immune system Toxins Naturally occuring Toxins may be associated with foodborne illness Naturally occuring Toxins examples Oaxlic acid, nitrites and nitrates, aflatoxin Marine Toxins In the US, the annual number of reported cases of poisoning from marine toxins is estimated to be 30

Page 302 Examples of marine toxins are ciguatoxin, produced by dinoflagellates that become concentrated in certain types of fish and shellfish scombroid toxin, elaborated by bacterial deterioration of certain species of fish (tuna) paralytic shellfish poison, produced by dinoflagellates that become concentrated in certain types of fish and shellfish Also produced by domoic acid toxic produced by marine diatoms puffer fish toxin Mushroom Toxins Produced naturally by mushrooms referred to as toadstools Most of the mushroom toxins that are linked to human poisoning cannot be deactivated by cooking, canning, freezing or any other kind of processing The only sure way to avoid mushroom poisoning is by avoiding consumption of toxic mushrooms Heavy Metals When present in high concentrations, heavy metals can cause vomiting that occurs a few minutes to several hours after ingestion Pesticides in Foods Dietary sources are one of the persistent means of exposure of the population to persistent organic chemicals The effects of high-level exposures often are acute The pesticide aldicarb has been detected in watermelons and caused illness Page 303 The outbreak of aldicarb contaminated watermelons was the largest foodborne pesticide illness outbreak ever recorded in North America The pesticide aldicarb is regarded as appropriate for use of citrus fruits and potato crops but not for use on melons Antimicrobials in Meat Antimicrobials that are smilier or identical to those used by humans are employed for disease prevention and growth enhancement among animals

E.g., amoxicillin, penicillin, bacitracin, erythromycin Page 304 Metaphylaxis - A procedure where antimicrobials are given to an entire collection of animals for the purpose of curing disease among the sick animals and preventing disease among the remainder Regarding the use of antimicrobials for growth enhancement of animals, antimicrobials increase the efficiency of feeds by reducing the amount of feeds that animals require Unlike chemical residues, there is an additional concern for the use of antimicrobial animal drugs of an indirect toxicity to the human consumer Characterized by the loss of an effective therapeutic intervention Resistance of microbials to antimicrobials Improved conditions for raising food animals and the use of vaccines can reduce the need for microbial agents Biotechnology and Genetically Modified Foods Biotechnology and genetically modified foods hold promise food addressing the need for more food supplies as the world’s population increase and available land and water for agricultural uses diminish Examples of GM foods are those that result from genes that have been manipulated Biotechnology can, and is, enhancing the quality of food in addition to improving the quantity of food Page 305 Food Additives Food Additives - Substances that become part of a food product when added (intentionally or unintentionally) during the processing or production of that food 3 categories of food additives Intentional (Direct) Additives - Added to foods in order to improve their quality Incidental (Indirect) Additives - Present in foods as a result of unintentional contamination during packaging, storage and handling Malicious Additives - Substance such as poisons that saboteurs introduce into foods for various reasons Additives include emulsifiers, stabilizers, thickeners, vitamins, minerals, preservatives Preservatives Preservatives - Act as antimicrobial agents and antioxidants Among the antimicrobial agents are

nitrates, BHA (butylated hydroxyl anisole), BHT (butylated hydroxytoluene), disodium EDTA, sulfites, propionates, parabens 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 Page 306 One concern about the use of nitrates and nitrites is that they may interact with amines to produce nitrosamines Nitrosamines are known carcinogens The safety of food additives is monitored by the FDA Regulation of Food Safety In the US, a body of governmental regulations is designed to assure the quality of food products and to protect the public from possible harm resulting from additives and chemicals in food The FDA is the US agency charged with regulation and enforcement of food safety The US Department of Agriculture (USDA) regulates the safety of meat and poultry products Food safety regulations that are in force at present are the result of an incremental process of change Examples of significant US food safety regulations 1. Food Quality Protection Act (FQPA) 2. Food and Drugs Act 3. Food Additives Amendments 4. Color Additive Amendments 5. Annual Drug Amendments Page 307 Agencies That Regulate Food Safety International: The Food and Agriculture Organization of the United Nations (FAO) Raise levels of nutrition and standards of living Improve agricultural productivity Better the condition of rural populations FAO is the largest specialized agency in the UN system and the lead agency for agriculture, forestry, fisheries and rural development National: The Food Safety and Inspection Service (FSIS) The public health regulatory agency in US department of Agriculture Responsible for ensuring that the nation’s commercial supply of meat, poultry, and egg products is safe, wholesome, correctly labeled and packaged

Page 308 National: The Center for Food Safety and Applied Nutrition (CFSAN) An arm of the US Food and Drug Administration (FDA) Regulates $417 billion worth of domestic food $49 billion worth of imported foods over $60 billion worth of cosmetic sold across state lines National: The Centers for Disease Control and Prevention Food Safety Office (FSO) Provides leadership in the control of foodborne illness in the US Investigates the source of foodborne disease outbreaks State: California Department of Health Services, Food and Drug Branch Protects and improves the health of all California residents by assuring that foods, drugs, medical devices, cosmetics and certain other consumer products are safe and are not adulterates, misbranded nor falsely advertised and that drugs and medical devices are effective Local: The LA County Department of Health Services, Division of Environmental Health, Bureau of District Environmental Services Protect health, prevent disease, and promote health for all persons in LA County Foodborne Disease Prevention In the US, 2 main factors are related to Foodborne disease outbreaks Improper temperatures for keeping foods Poor personal hygiene of food handlers Developing countries may have both or one of the US elements, in addition with no reliable water supply More than one factor at a time can be present as a cause of Foodborne illness Safe Cooling and Holding Temperatures In order to prevent microorganisms from multiplying in foods, they must be kept in the same temperature range Above 140 F for hot foods Below 40 F for foods that are kept in cold storage Page 310 Tha range between 40 F and 140 F is the DANGER ZONE The temperature range in which microbes that can cause Foodborne illness produce toxins or multiply Preventing Growth of Foodborne Pathogens

4 steps to prevent the growth of foodborne pathogens in food 1. Clean 1. Wash hands and surfaces often 2. Separate 1. Don’t cross contaminate 3. Cook 1. Cook to proper temperatures 4. Chill 1. Refrigerate properly Page 313 Irradiation During the process of irradiation, energy from ionizing radiation passes through foods and destroys bacteria and other pathogens The procedure does not cause food to become radioactive Exposing foods to radiation does not cause their temperatures to increase as with other methods of food preservation Reasoning why irradiation is called “Cold Pasteurization” The sources of ionizing radiation used in cold pasteurization include gamma radiation from cobalt-60 and cesium-137 Electromagnetic beam radiation X-rays A low dose of radiation (...