Food Borne Diseases And Its Prevention

Foodborne disease and its prevention

Definitions

Foodborne disease is any illness resulting from the consumption of food contaminated with one or more disease-producing agents. These include bacteria, parasites, viruses, fungi and their products as well as toxic substances not of microbial origin.

• Infection • Intoxication • Metabolic food disorder • Allergy • Idiopathic illness

The Food and Drug Administration (FDA) Ranking of Food Hazards ranking* 1. microbial contamination 2. naturally occurring toxicants 3. environmental contaminants (e.g., metals 4. nutritional problems (i.e., malnutrition, undernutrition) 5. pesticide residues 6. food additives *1 being most dangerous, 6 least dangerous

Major identified foodborne pathogens, United States – circa 2002 • Bacterial:  Bacillus cereus  Brucella  Campylobacter*  Clostridium botulinum  Clostridium perfringens  E. coli O157:H7*  E. coli, non-O157 STEC*  E. coli, other diarrheagenic*  Listeria monocytogenes*  Salmonella Typhi  Salmonella non-typhoidal  Shigella  Staphylococcus  Streptococcus  Vibrio cholerae, toxigenic*

•

Bacterial, continued:  Vibrio vulnificus*  Vibrio, other*  Yersinia enterocolitica*

•

Parasitic:  Cryptosporidium*  Cyclospora*  Giardia*  Toxoplasma*  Trichinella

•

Viral:  Norwalk-like viruses*  Rotavirus*  Astrovirus*  Hepatitis A

Prions*

* Recognized as foodborne in last 30 years (Zoonotic reservoir)

Classification of Foodborne Illness 1. Bacterial foodborne infection • Disease-causing organism is carried by food or water into the host • While infection occurs inside the body, there is lag-time:  onset time = time from infection to appearance of symptoms • Fever usually appears • Possibly nausea, headaches, vomiting and chills 2.

Bacterial foodborne intoxication (poisoning)  Organisms multiply to great numbers within the food product and then produce toxin in the process.  If enough quantities of the toxin are ingested, it’ll override the body’s immune system and cause illness.  Faster acting than food infections  NO fever usually (toxin acts immediately on the body)  Vomiting may result

Classification of Food Poisoning Toxins

1. Exotoxins • Released by the bacteria when they are alive and growing 

Endotoxins  Released by the bacteria after they die

1.

Enterotoxins  Toxins that develop in the gastro-intestinal tract

Toxins may be: 1.

Heat stable – hot temp. does not alter the toxin chemical e.g. Staphylococcus aureus toxin

1.

Heat labile – hot temp. alters the toxin protein which get deactivated e.g. Clostridium botulinum toxin

Food poisoning: Notifications and laboratory reports, 1995-2005, Northern Ireland Campylobacter sp

Cryptosporidium sp

Salmonella sp

Food Poisoning Notifications

Number of notifications/lab reports

2500

2000

1500

1000

500

0 1995

1996

1997

1998

1999

2000 Year

2001

2002

2003

2004

2005

Number of Lab Reports

Laboratory reports of Clostridium difficile toxin (all specimen types), 1995 – 2005, Northern Ireland 1600 1400 1200 1000 800 600 400 200 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Number of Lab Reports

Laboratory reports of Clostridium perfringens (all specimen types), 1995 – 2005, Northern Ireland 25 20 15 10 5 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Number of Lab Reports

Laboratory reports of Campylobacter sp (all specimen types), 1995 – 2005, Northern Ireland 1200 1000 800 600 400 200 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Number of Lab Reports

Laboratory reports of Cryptosporidium sp (all specimen types), 1995 – 2005, Northern Ireland 450 400 350 300 250 200 150 100 50 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Number of Lab Reports

Laboratory reports of Escherichia coli O157 (all specimen types), 1995 – 2005, Northern Ireland 60 50 40 30 20 10 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Laboratory reports of Giardia lamblia (all specimen types), 1995 – 2005, Northern Ireland Number of Lab Reports

60 50 40 30 20 10 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Laboratory reports of Listeria sp (all specimen types), 1995 – 2005, Northern Ireland Number of Lab Reports

7 6 5 4 3 2 1 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Number of Lab Reports

Laboratory reports of Rotavirus (all specimen types), 1995 – 2005, Northern Ireland 700 600 500 400 300 200 100 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Laboratory reports of Salmonella sp, 1995-2005, Northern Ireland 800 Salmonella (total) S. enteritidis S. typhimurium

Number of Lab Reports

700 600 500 400 300 200 100 0 1995

1996

1997

1998

1999

2000 Year

2001

2002

2003

2004

2005

Number of Lab Reports

Laboratory reports of Salmonella sp (all specimen types), 1995 – 2005, Northern Ireland 800 700 600 500 400 300 200 100 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Number of Lab Reports

Laboratory reports of Salmonella enteritidis (all specimen types), 1995 – 2005, Northern Ireland 500 400 300 200 100 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Number of Lab Reports

Laboratory reports of Salmonella enteritidis PT4 (all specimen types), 1995 – 2005, Northern Ireland 450 400 350 300 250 200 150 100 50 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Number of Lab Reports

Laboratory reports of Salmonella typhimurium (all specimen types), 1995 – 2005, Northern Ireland 200 150 100 50 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Laboratory reports of Salmonella typhimurium DT 104 (all specimen types), 1995 – 2005, Northern Ireland 140 120 100 80 60 40 20 0 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05

Number of Lab Reports

160

Year

300 250 200 150 100 50 0 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05

Number of Lab Reports

Laboratory reports of Shigella sp (all specimen types), 1995 – 2005, Northern Ireland

Year

Number of Lab Reports

Laboratory reports of Norovirus (all specimen types), 1995 – 2005, Northern Ireland 450 400 350 300 250 200 150 100 50 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year

Outbreaks vs. Cases • Foodborne disease outbreak: an incident in which two or more persons experienced a similar illness after ingestion of a common food, and epidemiologic analysis implicated a food as the source of illness. • Foodborne disease case: one individual experiences illness after ingestion of an epidemiologically incriminated food.

Estimates of the yearly incidence of foodborne illness • The estimates vary greatly but thought to be around 76 million cases per year • Cost estimates range from $5–23 billion per year • High cost due to many factors: – medical care, investigation of illness, loss of productivity, loss of business, legal activities

Information reported to and compiled by the Centers for Disease Control (CDC) Outbreaks of known etiology = where laboratory evidence indicated a specific agent Outbreaks of unknown etiology = where epidemiological evidence implicated foodborne transmission, but the etiological agent was not identified. 4 subgroups based on incubation period: < 1 hr = probable chemical poisoning 1 – 7 hr = probable Staphylococcus aureus poisoning 8 – 14 hr = probable Clostridium perfringens food poisoning > 14 hr = probably other infectious/toxic agents Outbreaks of known vehicle =a particular food item was associated with the illness

Number of reported foodborne-disease outbreaks, cases, and deaths, by etiology — United States, 1993–1997 Outbreaks No. (%)

Cases No. (%)

Bacterial

655(23.8)

Chemical

148(5.4)

576(0.7)

0(0)

Parasitic

19(0.7)

2,325(2.7)

0(0)

Viral

56(2.0)

4,066(4.7)

0(0)

Confirmed etiology878 (31.9)

43,821(50.9)

50,788(59.0)

Deaths No. (%)

28(96.6)

28(96.6)

Unknown etiology1,873(68.1) 35,270(41.0)

1(3.4)

Total 1993–19972,751(100.0) 86,058(100.0)

29(100.0)

ex MMWR Table 1, Vol. 49/No. SS-1, p. 11 http://www.cdc.gov/mmwr/preview/mmwrhtml/ss4901a1.htm

Foodborne diseases Infection with a variety of different pathogens Illness may occur in large focal outbreaks Most illness is “sporadic”: either individual cases or

part of unrecognized dispersed outbreaks

Reservoir: locus of sustained transmission and

persistence

• Some have a human reservoir: Shigella, hepatitis A, Norwalk

virus

• Some have an animal reservoir: Salmonella, Campylobacter,

E. coli O157:H7, Listeria, Vibrio, Yersinia, Toxoplasma

Often transmitted by several different pathways

• Specific foods, water, direct contact with animals, direct

contact with humans

The new foodborne zoonoses The infected food animal looks healthy Sustained or repeated infections in animals Contaminated food looks normal Pathogen survives standard processing and preparation Missed by current inspection strategies Spreads silently around the globe Requires new control strategies More to be discovered

Estimated illnesses for known foodborne pathogens, United States Disease or agent

Estimated total cases

Bacteria5,204,934 Parasites2,541,316 Viruses30,883,391 Grand Total38,629,641 ex Mead, P. S., L. Slutskaer, V. Dietz, L. F. McCaig, J. S. Bresee, C. Shapiro, P. M. Griffin, and R. V. Tauxe. Food-related illness and death in the United States. Emerging Infectious Diseases 5(5):607–625 (1999). http://www.cdc.gov/ncidod/eid/vol5no5/mead.htm

Public health burden of foodborne disease Each year an estimated 76 million cases

• 1 in four Americans gets a foodborne illness each

year • 1 in 1000 Americans is hospitalized each year • $6.5 billion in medical and other costs

• Prevention depends on efforts from farm to

table to reduce contamination of food

Public health burden of foodborne disease 1997 Estimate: each year an estimated 76 million

cases* • 1 in four Americans gets a foodborne illness each year • 1 in 1000 Americans is hospitalized each year

Prevention depends on efforts from farm to table to

reduce contamination of food

Healthy People Goals for 2010: 50% reduction from

1997 baseline in incidence of infections with: • Salmonella • Campylobacter • E. coli O157 • Listeria monocytogenes • Outbreaks caused by Salmonella Enteritidis

* Mead, EID 5:607, 1999

Top Twelve Factors Contributing to 345 Outbreaks of Foodborne Disease Caused by Mishandling and/or Mistreatment of Foods in Homes in the U.S., 1973–1982 Ranking Contributing Factor Percent* 1. Contaminated raw food/ingredient 42.0 2. Inadequate cooking/canning/heat processing 31.3 3. Obtained food from unsafe source 28.7 4. Improper cooling 22.3 5. Lapse of 12 or more hours between preparing and eating 12.8 6. Colonized person handling implicated food9.9 7. Mistaken for food 7.0 8. Improper fermentations 4.6 9. Inadequate reheating 3.5 10. Toxic containers 3.5 11. Improper hot holding 3.2 12. Cross-contamination 3.2 *Percentage exceeds 100 because multiple factors contribute to single outbreak

Organisms that Cause Bacterial Foodborne Infections

Infection • Definition: a disease state caused by the presence of viable, usually multiplying organisms at the site of inflammation – – – –

Bacteria Virus Protozoa other parasites

- Salmonella, Campylobacter - hepatitis A, Norwalk virus - Cryptosporidium, Cyclospora - Trichinella spiralis

Sources of Foodborne Pathogens “You

mean there are things on my hands that can make people sick?”

Overview • • • • • • • •

Microorganisms Susceptible Populations Infectious Doses Intoxication vs. Infection Fungal Pathogens Parasitic Pathogens Bacterial Pathogens Viral Pathogens

Pathogenic Microorganisms • • • •

Fungi Parasites Bacteria Viruses

Salmonella - salmonellosis • Symptoms - 7-72 hrs • Livestock, poultry, eggs, pets, wild animals, people • Meat, poultry, eggs/products, unpasteurized dairy

• Over 2000 Salmonella • Grow well at 95 oF • Healthy adults – ingest thousands to get ill; young children, elderly - few cells • Killed by heat if hot enough – 150o F

Eggs - Salmonella Enteritidis • Uncracked shell eggs --- 3-7% • Transmission from hen to egg before egg is laid • Processed foods pasteurized eggs required – examples:

Campylobacter jejuni campylobacteriosis • Sym – headache, fever, abdominal pain, recurring over several weeks • Anaerobic bacteria, no spores • Source: livestock of various species • Foods: meat, poultry, unpasteurized dairy, cross-contaminated foods • Very frequent cause of illness

Escherichia coli O157:H7 • • • •

First recognized in 1982 Infection and/or intoxication Causes severe illness/kidney failure/death Sym - ab pain, fever, cramps, nausea, bloody diarrhea - particularly harmful to children, elders • Secondary infections caused by • poor hand washing

• Source - intestinal tract of livestock, wild game, • Food: ground beef, other undercooked meats, apple cider, water

Listeria monocytogenes Listeriosis • Meningitis • Nausea, vomiting, headache in healthy adults. • Miscarriage, stillbirth in pregnant women. • Retardation, meningitis, deaths in newborns

• 1 day to 3 weeks • Source • Unpasteurized dairy; raw, soil-grown vegetables may be contaminated; raw meats and poultry, processed meats

Viral Causes of FBI

Hepatitis A virus • Sym - Fever, nausea, ab pain, fatigue, jaundice, may be liver involvement • 15-50 days onset • Source: human • Foods - Prepared salads, oysters/clams - raw or slightly cooked • Does not reproduce in food

Norwalk virus • Sym - ab pain, vomiting, diarrhea, headache, low grade fever • 1-2 days for onset • Source - human • Does NOT reproduce in food • Virus particles stay viable a long time

Intoxication • Definition: a disease state, caused by exposure to a toxic chemical, that is not mediated immunologically and is not primarily the result of a genetic deficiency. – Staphylococcal food poisoning, botulism – Saxitoxin, ciguatera

Foodborne Intoxications

Staphphyloccus aureus - food intoxication • Bacteria secrete toxins into surrounding food as they grow. • Bacteria killed by heat; but toxin is very heat stabile • Sym.- nausea, vomiting, diarrhea, cramps, dehydration, prostration. • 1-7 hours after eating toxin in food - FAST

• Source - people ! • 40 - 50 % of all healthy adults are carriers. • Found in nasal passage, cuts, wounds, boils, acne,skin. potato • Foods: ham, chicken and salads, cream fillings good places for bacteria to grow and produce toxin • Under what conditions?

Clostridium botulinum - botulism • Rare but very serious, often fatal or long-term recovery. • Symptoms: double vision, constipation; difficult eye movement, swallowing, speech, loss of autonomic nervous system function • Spore forming, anaerobic - organism becomes vegetative and produces toxin • Vegetative and spore forms found in soil, water, intestinal tracts of animals, fish

Processed Foods • Improperly canned low acid meats, vegetables • Smoked, vacuum-packed fish • Other improperly prepared and held, modified - atmosphere packaged

Clostridium perfringens • Toxin-mediated infection - organisms eaten in food, stay in intestine and produce toxin • Mild illness • Sym 8-22 hours • Source- soil, dust, human and animal feces • Foods - cooked meats, chili, stews, poultry, gravies, baked beans, other thick dishes

Foodborne Diseases

Infections

Intoxications

Chemical Poisoning

Poisonous Plant Tissues

Poisonous Animal Tissues

Toxicoinfection

Microbial Intoxications

Other

Neurotoxins

Invasive Infection

Enterotoxins

Intestinal Mucosa Mycotoxins (Fungal Toxins)

Algal Toxins

Bacterial Toxins

Diarrhogenic

Emetic

Enterotoxins

Neurotoxins

Other

Systemic

Other Tissues or Organs (Muscle, Liver, Joints, Fetus, Other)

Foodborne Diseases Intoxications

Infections

Toxicoinfection

Other

Neurotoxins

Invasive Infection

Enterotoxins

Intestinal Mucosa

Systemic

Other Tissues or Organs (Muscle, Liver, Joints, Fetus, Other)

Foodborne Diseases Intoxications

Chemical Poisoning

Infections

Poisonous Plant Tissues

Poisonous Animal Tissues

Microbial Intoxications

Mycotoxins (Fungal Toxins)

Diarrhogenic

Emetic

Enterotoxins

Algal Toxins

Bacterial Toxins

Neurotoxins

Other

Examples of foodborne infections/intoxications Disease

Reservoir

Botulism food intoxication

Soil contaminated foods

Campylobacteriosis

Cattle, poultry, shellfish

Clostridium perfringens food poisoning

Soil contaminated foods

Salmonellosis

Animals and birds

Staphylococcal food poisoningHuman carriers Vibrio parahaemolyticus infection

Seafoods

Yersinia enterocolitica infection

Animal intestines

Objectives of foodborne disease surveillance prevention and control: identification of contaminated products knowledge of disease causation: observe the track record of various illnesscausing agents administrative guidance: assessment of trends to justify regulatory decisions/actions

Susceptible Populations  Elderly

and infants  Pregnant women  Impaired immune system (AIDS)  Cancer patients  Organ transplant recipients  Predisposing illness (ex. alcoholism, diabetes, cirrhosis of the liver)

Infectious Doses

 Minimum infectious dose (MID) not

determined for most pathogens  Consumption of just a few (10-100) organisms in some individuals may cause disease (depends upon immune status)  High numbers (>106) of organisms may be required to cause disease in healthy adults

Infection vs. Intoxication

Foodborne Infection • occurs when pathogens (bacteria, viruses, or parasites) are ingested with food and multiply in the human body • symptoms can occur 1 to 50 days after ingestion • symptoms may include fever, chills, malaise, headache, vomiting, diarrhea, dehydration, intestinal cramping, arthritis (3-4 weeks later), septicemia, miscarriages, stillbirths, death

Examples of Foodborne Infection • Virus: Hepatitis A, Norwalk, Rotavirus • Bacteria: Salmonella spp., Vibrio spp. Campylobacter spp., Yersinia spp., Shigella spp., Listeria monocytogenes • Parasite: Trichinella spiralis, Anisakis simplex, Giardia duodenalis (protozoan)

Foodborne Intoxication • occurs when food are ingested that contain toxins produced by bacteria or molds • toxins may be heat stable • symptoms can occur within minutes to 15 hours after ingestion • symptoms may include headache, vomiting, diarrhea, dehydration, intestinal cramping, weakness, blurred vision --> paralysis/death (ex. C. botulinum); no fever

Examples of Foodborne Intoxication • Staphylococcus aureus • Bacillus cereus • Clostridium botulinum • Aspergillus flavus/parasiticus

Foodborne Parasites • • • •

Trichinella spiralis Giardia lamblia Cryptosporidium parvum Cyclospora

Trichinella spiralis

Trichinella spiralis Nematode/roundworm AKA=Trichinosis Foodborne infection; 2-28 days Symptom: abdominal pain, fever, thirst, bleeding Found in pigs, wild game Associated foods: undercooked pork or wild game Controlled by freezing, cooking, salting, irradiation

Giardia lamblia

Giardia lamblia • Flagellated protozoan • Found in domesticated and wild animals, humans, rodents, contaminated water supplies • Foodborne infection-1 week • May require only 1 cyst to cause infection • Diarrhea

Giardia lamblia • Associated foods: salads, water  Poor personal hygiene is responsible for contamination of foods handled by infected employees

Cryptosporidium parvum

Cryptosporidium parvum • Protozoa, obligate intracellular parasite • Found in domesticated and wild animals, humans, rodents, contaminated water supplies • Foodborne infection • May require only 10 organisms to cause infection • Symptoms: Severe watery diarrhea

Cryptosporidium parvum • Associated foods: water, vegetables treated with animal manure • Poor personal hygiene is responsible for contamination of foods handled by infected employees

Cyclospora

Cyclospora • • • •

Unicellular parasite Associated with contaminated water supplies, human waste Foodborne infection-1 week Symptoms: Watery diarrhea, explosive bowel movements, stomach cramping, low grade fever

Cyclospora • Associated foods: water, fruits and vegetables treated with animal manure • Poor personal hygiene is responsible for contamination of foods handled by infected employees

Bacterial Pathogens • Salmonella spp. • Listeria monocytogenes • Campylobacter jejuni • E. coli O157:H7 • Staphylococcus aureus

Clostridium spp. Aeromonas spp. Vibrio spp. Yersinia spp. Shigella spp. 

Bacteria Differentiated according to ability to retain specific stains Gram Stain: Gram Positive Gram Negative

Salmonella spp.

Salmonella spp. Gram negative, non-spore forming, aerobic, motile rod Found in animals, man, soil, water, insects, raw meat, poultry, seafood, kitchens Foodborne infection; 1-2 days As few as 20 cells-10,000 cells may cause disease (depends upon host, age, etc). Symptoms: Diarrhea, fever, vomiting, severe dehydration

Salmonella spp. May cause arthritis (3-4 weeks after infection) Associated foods: undercooked poultry and meat, beef jerky, unpasteurized or contaminated milk, salad dressings, cream filled desserts, eggs, orange juice

Listeria monocytogenes

Listeria monocytogenes Gram positive, non-spore forming, facultative anaerobe, motile rod Found in intestinal tracts of man, birds, soil, silage, water, livestock, cold & damp areas Survives drying, refrigeration, freezing, and heat treatments Foodborne infection; 3-70 days

Listeria monocytogenes Symptoms: Diarrhea, meningitis, encephalitis, septicemia, miscarriages, stillbirths Infective dose may be <1000 cells Associated foods: RTE meats, hot dogs, deli meats, unpasteurized dairy products, ice cream, raw vegetables, fermented sausages, raw meat, poultry

Campylobacter jejuni

Campylobacter jejuni Gram negative, non-spore forming, motile rod Microaerophilic-low oxygen Found in man, animals (domestic and wild), birds, flies, water Foodborne infection; 2-5 days As few as 400-500 cells cause infection

Campylobacter jejuni Symptoms: Watery-bloody diarrhea, Guillain Barre syndrome May be most common cause of gastroenteritis in US Associated foods: undercooked poultry and meat, unpasteurized milk, contaminated water

Escherichia coli O157:H7

E. coli O157:H7 Gram negative, non-spore forming, aerobic, rod Found in intestinal tracts of cattle, deer, birds, man Foodborne infection; 3-4 days Acid tolerant, heat tolerant Symptoms: bloody diarrhea, fever, severe cramping, Hemolytic Uremic Syndrome (HUS)

E. coli O157:H7 As few as 10 cells may cause disease Associated foods: undercooked hamburgers, venison jerky, water, unpasteurized milk, fermented sausages, sprouts, water, roast beef, apple cider, salami, lettuce, yogurt, cantaloupe

Staphylococcus aureus

Staphylococcus aureus Gram positive, aerobic cocci Staph are found in air, dust, sewage, water milk, food, equipment, animals and humans: skin, hair, nose, throat, open sores, boils, saliva Transmitted to foods via handling, coughing, sneezing, wiping

Staphylococcus aureus Foodborne intoxication; hours Symptoms: Vomiting, abdominal cramping Organism produces toxin in food Toxin is heat stable Associated foods: cured meat products, improperly cooled food products, salads (ex. egg, tuna, chicken, potato, macaroni), crème filled pastries, canned mushrooms

Clostridium perfringens

Clostridium perfringens Gram positive, spore forming, anaerobic rod Found in soil, intestinal tracts of man and animals Foodborne infection;8-22 hours; toxin is formed in the gut Symptoms: Diarrhea, severe dehydration, cramps

Clostridium perfringens Large number of cells (108) needed to cause disease Associated foods: temperature abused foods, roast beef, stews, meat gravy, poultry

Clostridium botulinum

Clostridium botulinum Gram positive, spore forming, anaerobic rod Found in soil, water, animal, poultry, vegetables, shellfish, horses, fish Foodborne intoxication; hours Symptoms: Paralysis, blurred vision, death Toxin is susceptible to heat (175F, 10 min)

Clostridium botulinum Associated foods: honey, improperly canned foods, underprocessed or temperature abused foods, stews, meat/poultry loaves; sausages, seafood products, garlic-in-oil, liver pate, smoked and salted fish, baked potatoes, pickled eggs

Aeromonas hydrophila

Aeromonas hydrophila Gram negative, non-spore forming, aerobic rod Found in brackish freshwater, seafood, fish, salt water Foodborne infection Symptoms: Watery diarrhea, dehydration, septicemia Associated foods: fish, shellfish, beef, pork, lamb, poultry

Vibrio spp.

Vibrio vulnificus Gram negative, non-spore forming, aerobic rod Found in fresh and salt water, plankton, shellfish, brackish lakes Foodborne infection or enters via wound (shucking oysters, stepping on shell, etc).

Vibrio vulnificus Symptoms: Diarrhea, septicemia, septic shock, death Associated foods: raw, undercooked, or contaminated oysters, clams, crabs

Yersinia enterocolitica

Yersinia enterocolitica  Gram negative, non-spore forming, aerobic rod  Found in domestic and wild animals, pigs, ponds, lakes, birds, beavers  Foodborne infection  Symptoms:Diarrhea, cramps, nausea, vomiting, fever, severe abdominal pain (mimic appendicitis), septicemia

Yersinia enterocolitica  Associated foods: pork, beef, lamb, oysters, fish, raw milk, chocolate milk, tofu, chitterlings

Shigella spp.

Shigella spp.  Gram negative, non-spore forming, nonmotile, aerobic rod  Found in feces of humans and primates, water contaminated with human feces  Foodborne infection (12-50 hours)  Need as few as 10 cells to cause disease  Symptoms: Diarrhea, cramps, nausea, vomiting, fever, mucus in stools

Shigella spp.  Associated foods: potato, tuna, shrimp, macaroni, chicken salads, raw vegetables, milk and other dairy products  Fecally contaminated water and poor personal hygiene are the most common causes of contamination

Viruses Hepatitis A Rotavirus Norwalk

Hepatitis A

Hepatitis A AKA: type A viral hepatitis Excreted in feces of infected employees Foodborne infection (10 to 50 days) Infection may occur with approximately 10100 virus particles Symptoms: Fever, malaise, nausea, abdominal discomfort, jaundice Associated foods: deli meats, salads, beverages, sandwiches, fruits, dairy products

Hepatitis A Poor personal hygiene is responsible for contamination of foods handled by infected employees

Rotavirus

Rotavirus AKA: Viral gastroenteritis Excreted in feces (108-10 ) of infected employees; found in fecally contaminated water supplies Foodborne infection (1-3 days) Symptoms: Vomiting, diarrhea, dehydration Poor personal hygiene is responsible for contamination of foods handled by infected employees

Norwalk Virus

Norwalk Virus AKA= Norwalk-like virus, viral gastroenteritis Found in contaminated water supplies; contaminated shellfish beds, cruise ships Foodborne infection: 1-2 days Symptoms: Nausea, vomiting diarrhea, abdominal pain, low grade fever Poor personal hygiene is responsible for contamination of foods handled by infected employees

Norwalk Virus Associated foods: fruits, eggs, clams, oysters, bakery items, salads, ice, shrimp

Botulism Botulinim toxin

History • Neurologic disease from botulinum toxin – Most lethal substance known

History • Neurologic disease from botulinum toxin – Most lethal substance known

• History as bioweapon

History • Neurologic disease from botulinum toxin – Most lethal substance known

• History as bioweapon – Japanese in WWII (Unit 731)

History • Neurologic disease from botulinum toxin – Most lethal substance known

• History as bioweapon – Japanese in WWII (Unit 731) – Former US and USSR programs

History • Neurologic disease from botulinum toxin – Most lethal substance known

• History as bioweapon – Japanese in WWII (Unit 731) – Former US and USSR programs – Iraqi deployed weapons

History • Neurologic disease from botulinum toxin – Most lethal substance known

• History as bioweapon – – – –

Japanese in WWII (Unit 731) Former US and USSR programs Iraqi deployed weapons Japanese cult in early 1990’s

Epidemiology • Found worldwide • U.S. incidence – ~100 cases annually (1/4 foodborne)

Epidemiology • Mechanisms of intoxication – No person-to-person transmission

Epidemiology • Mechanisms of intoxication – No person-to-person transmission – Toxin ingestion (foodborne)

Epidemiology • Mechanisms of intoxication – No person-to-person transmission – Toxin ingestion (foodborne) – Toxin generated from wound infection (wound)

Epidemiology • Mechanisms of intoxication – – – –

No person-to-person transmission Toxin ingestion (foodborne) Toxin generated from wound infection (wound) Toxin from intestinal colonization (infant, intestinal)

Epidemiology • Mechanisms of intoxication – – – – –

No person-to-person transmission Toxin ingestion (foodborne) Toxin generated from wound infection (wound) Toxin from intestinal colonization (infant, intestinal) Toxin inhalation (aerosol release)

Epidemiology • Mechanisms of intoxication – – – – –

No person-to-person transmission Toxin ingestion (foodborne) Toxin generated from wound infection (wound) Toxin from intestinal colonization (infant, intestinal) Toxin inhalation (aerosol release)

• Mortality <10%

Microbiology • Clostridium botulinum

Microbiology • Clostridium botulinum – Large, anaerobic Gram positive bacillus – Spore-forming

Microbiology • Clostridium botulinum – Large, anaerobic Gram positive bacillus – Spore-forming – Rarely infects humans

Microbiology • Clostridium botulinum – – – –

Large, anaerobic Gram positive bacillus Spore-forming Rarely infects humans Produces potent neurotoxin • 7 types (A-G)

Microbiology • Clostridium botulinum – – – –

Large, anaerobic Gram positive bacillus Spore-forming Rarely infects humans Produces potent neurotoxin • 7 types (A-G) • Types A, E, B most common in U.S.

Microbiology • Clostridium botulinum – – – –

Large, anaerobic Gram positive bacillus Spore-forming Rarely infects humans Produces potent neurotoxin • 7 types (A-G) • Types A, E, B most common in U.S. • Same general mechanism

Arnon S, et al. JAMA. 2001;285:1059-70.

Clinical Features • Incubation 12-72 hours – Probably faster if inhalational exposure

Clinical Features • Classic syndrome

Clinical Features • Classic syndrome – Acute symmetric cranial nerve palsies

Clinical Features • Classic syndrome – Acute symmetric cranial nerve palsies • Blurry vision, ptosis, dysphasia

Clinical Features • Classic syndrome – Acute symmetric cranial nerve palsies • Blurry vision, ptosis, dysphasia

– Descending flaccid paralysis

Clinical Features • Classic syndrome – Acute symmetric cranial nerve palsies • Blurry vision, ptosis, dysphasia

– Descending flaccid paralysis • Complete skeletal muscle paralysis

Clinical Features • Classic syndrome – Acute symmetric cranial nerve palsies • Blurry vision, ptosis, dysphasia

– Descending flaccid paralysis • Complete skeletal muscle paralysis • Respiratory (ventilatory) failure

Clinical Features • Classic syndrome – Acute symmetric cranial nerve palsies • Blurry vision, ptosis, dysphasia

– Descending flaccid paralysis • Complete skeletal muscle paralysis • Respiratory (ventilatory) failure

– Autonomic – urinary retention, orthostasis

Clinical Features • Classic syndrome – Acute symmetric cranial nerve palsies • Blurry vision, ptosis, dysphasia

– Descending flaccid paralysis • Complete skeletal muscle paralysis • Respiratory (ventilatory) failure

– Autonomic – urinary retention, orthostasis – Afebrile, normal mentation

Clinical Features • Differential Diagnosis

Clinical Features • Differential Diagnosis – Myasthenia Gravis – anticholinesterase response

Clinical Features • Differential Diagnosis – Myasthenia Gravis – anticholinesterase response – Guillaine-Barre Syndrome - ascending

Clinical Features • Differential Diagnosis – Myasthenia Gravis – anticholinesterase response – Guillaine-Barre Syndrome - ascending – Stroke – asymmetric, abnormal brain imaging

Clinical Features • Differential Diagnosis – Myasthenia Gravis – anticholinesterase response – Guillaine-Barre Syndrome - ascending – Stroke – asymmetric, abnormal brain imaging – Tick paralysis – ascending, presence of tick

Clinical Features • Differential Diagnosis – Myasthenia Gravis – anticholinesterase response – Guillaine-Barre Syndrome - ascending – Stroke – asymmetric, abnormal brain imaging – Tick paralysis – ascending, presence of tick – Poliomyelitis – asymmetric, preceding viral illness

Clinical Features • Other features – Foodborne – nausea, diarrhea, dry mouth

Clinical Features • Other features – Foodborne – nausea, diarrhea, dry mouth – Infant - constipation

Diagnosis • High index of suspicion necessary – No readily available rapid confirmatory tests

Diagnosis • High index of suspicion necessary – No readily available rapid confirmatory tests

• Clinical diagnosis

Diagnosis • Laboratory confirmation – Specimens – blood, stool – At reference labs – Mouse bioassay – ELISA

Treatment • Supportive care

Treatment • Supportive care – Mechanical ventilation, nutritional support – Prevention of secondary infections

Treatment • Supportive care – Mechanical ventilation, nutritional support – Prevention of secondary infections – Avoid aminoglycosides, clindamycin

Treatment • Passive immunization (antitoxin)

Treatment • Passive immunization (antitoxin) – Halts paralysis, doesn’t reverse

Treatment • Passive immunization (antitoxin) – Halts paralysis, doesn’t reverse – Must be given ASAP

Treatment • Passive immunization (antitoxin) – Halts paralysis, doesn’t reverse – Must be given ASAP – Equine antitoxin (Types A, B and E toxins) • Serum sickness (9%), anaphylaxis (2%)

Treatment • Passive immunization (antitoxin) – Halts paralysis, doesn’t reverse – Must be given ASAP – Equine antitoxin (Types A, B and E toxins) • Serum sickness (9%), anaphylaxis (2%)

– Heptavalent antitoxin (Types A-G) • Investigational, less hypersensitivity

Post-Exposure Prophylaxis • Antitoxin not recommended – High incidence hypersensitivity – Limited supplies

Post-Exposure Prophylaxis • Antitoxin not recommended – High incidence hypersensitivity – Limited supplies

• Clinical monitoring – Extreme vigilance for symptoms – At least 72 hours – Antitoxin immediately for any symptoms

Vaccination • Botulinum toxoid – No role for post-exposure prophylaxis • Immunity develops over months

Vaccination • Botulinum toxoid – No role for post-exposure prophylaxis • Immunity develops over months

– Excellent efficacy • Not tested versus aerosol exposure

– Few adverse effects

Infection Control • No person-to-person transmission • Patient handling – Standard precautions

• Clinical specimens – Standard precautions

Metabolic food disorder • Definition: a disease state caused by exposure to a chemical that is toxic to certain individuals only because they exhibit some genetic deficiency – lactose intolerance – favism

Allergy

• Definition: a disease state caused by exposure to a particular chemical that (often proteinaceous) to which certain individuals have a heightened sensitivity (hypersensitivity) that has an immunological basis – proteins (heat resistant and resistant to digestion) • cow’s milk: β -lactoglobulin, casein, etc. • egg-ovalbumin – small molecules • penicillin

Idiopathic illness • Definition: any illness of uncertain pathogenesis that may possibly but not certainly be due to foods; also, any food-caused illness that does not fit into one of the other categories – Chinese restaurant syndrome – celiac disease – hyperkinesis

Foodborne diseases: Philosophy of prevention No vaccines for most of these pathogens Educating consumers, foodhandlers and producers is important, but

not sufficient

Groups at highest risk: Young children, elderly, immunocompromised Contamination can occur from farm to table Understand mechanisms of contamination well enough to prevent it

upstream from the consumer

Targets: Specific pathogen – food combinations

“The World Health Organization’s Golden Rules for Safe Food Preparation” 1. Choose foods processed for safety 2. Cook food thoroughly 3. Eat cooked foods immediately. 4. Store cooked foods carefully. 5. Reheat cooked foods thoroughly. 6. Avoid contact between raw and cooked foods. 7. Wash hands repeatedly. 8. Keep all kitchen surfaces meticulously clean. 9. Protect foods from insects, rodents, and other animals. 10. Use pure water.