Food Borne Diseases
Most foodborne outbreaks go unreported because many food borne illnesses are selflimiting
and few seek medical attention. Groups that may be at a higher riskof becoming seriously ill from
a food borne or water borne disease are theelderly, preschool aged children, pregnant women
and people who are already ill.
Diseasecausing agents are not detectable in food. Food that iscontaminated with diseasecausing
microorganisms and/ or their toxins maylook, smell and taste fine.
Hazards:
The three primary hazards that may contaminate food and cause food bornedisease are
biological, physical and chemical.
- Biological hazards, which are primarily microorganisms, may occur in food naturally,
- and grow andmultiply in certain food.
Biological hazards consist mainly of three groups of microorganisms: bacteria,viruses and protozoa.
Bacteria, viruses and protozoa get into food through crosscontamination, fecal/oral transmission,
using untreated water.
Virusesand protozoa do not grow or multiply in food; they only grow and multiple in a living host.
Bacteria on the other hand, are capable of growing and multiplying in potentially hazardous food.
- Chemical and physical hazards may accidentally get into food and cause food poisoning or choking.
It is a food operator’s primaryresponsibility to prevent contamination of food, control the growth
of natural contaminates in food and destroy natural contaminates in food, whenpossible, through cooking.
However, most food borne diseases may be prevented by employing good hand wash techniques.
Chemical hazards include sanitizing agents (bleach and Quats), medications, cleaning supplies and pesticides.
Common Food borne pathogens:
Bacterias:
Bacillius cereus
What is it?
Is an aerobic sporeformer that produces two toxins in food, one toxin causesvomiting, which is
heat stable and the other toxin causes diarrhea that may be destroyed by heat.
Where is it found?
This bacteria is found in soil and on dry, processed foods, such as rice and other grains.
Prevention
The best way to prevent this disease is to:
- Properly cool and reheat potentially hazardous foods, such as rice, beans and vegetables.
- It is important to remember that B. cereusproduces two toxins, one destroyed by proper
- reheating and one that is not destroyed by heat.
- Properly cool food. Cool the food by placing no more then 2” of food ina shallow pan.
- Refrigerate the hot food
- to be cooled immediately, checkthe temperature after 4 hours to verify the food has cooled to 45°F.
- Additional preventive steps in proper food practices are to rapidly reheatfood to 165˚F
- before it is served hot and do not hold food in a cooler at45˚F for longer than 4 days.
- The latter precaution is necessary becausebacteria can grow and multiply at 450F,
- and after four days bacterial numbers may be great enough to cause a food borne outbreak.
What is it?
This bacterium is a sporeformer that causes a toxinmediated infection. The bacterium
grows under anaerobic conditions in potentially hazardous foodand once consumed infects
the digestive tract and elaborates an enterotoxin that results in a food borne illness.
Where is it found?
Clostridium perfringens is found in soil, sediment and in the intestinal tracts of healthy humans and other animals.
Prevention
The best way to prevent this food borne disease is to:
- Properly cool and reheat potentially hazardous food, since bacterial spores survive cooking temperatures.
- Properly cool food.
- Hot food needs to be placed in shallow containers in smallquantities so the food is no greater than two inches deep.
- Hot food must beplaced in a cooler immediately so it will cool to 45˚F within 4 hours
- if coolermaintains 45˚F or less, or cool from 140˚F to 70˚F in 2 hours or less, then from 70˚F
- (if cooler maintains 41˚F or less).
- Additional preventive steps in proper food practices are to rapidly reheat foodto 165˚F before it is served hot
- and do not hold food in a cooler at 45˚F forlonger than 4 days or at 41˚F for longer than 7 days.
- The latter precaution isnecessary because bacteria can grow and multiply at 41˚F,
- and after four daysor sooner, bacterial numbers may be great enough to cause a food borne illness.
What is it?
Botulism is a food poisoning that is caused by a rodshaped bacterium calledClostridium botulinum.
This bacterium is a sporeformer that produces a neurotoxinin the presence of low acid food under
anaerobic conditions (devoid of oxygen), suchas canned vegetables and packaged meat products.
Clostridium botulinum producestoxins A, B, E, F and G, but most outbreaks are due to toxins A, B, E and F.
All ofthese toxins are heat liable, and may be destroyed by heat (boiling temperatures).
Where is it found?
Clostridium botulinum is worldwide and may be found in soil, sediment of lakes and ponds,
and in the digestive tract of fish and other animals.
Prevention
This disease can be avoided by:
• Not consuming food from damaged or bulging hermetically sealed cans or packages.
Food operators cannot serve “home” canned or hermeticallypackaged food to guests
because home processing is inconsistent and may fail to destroy all botulism spores,
therefore increasing the risk ofbotulism poisoning.
Hermetically processed food for guests must be froman approved commercial source,
and in good physical condition.
Cannedor packaged low acid food, such as vegetables and meats, should be boiled prior to consumption
as an extra precaution in case a container hasphysical damage that is invisible.
- Other actions that may be taken include immediate chilling
- (do notallow the food to sit at “room” temperature) of baked potatoes and other cooked vegetables
- to 45˚F within 4 hours to prevent bacteria likebotulism from growing and producing their toxins.
- Also, opened packages and containers of low acid food must be immediately
- placed in a cooler at 41˚F or 45˚F or less to preventbacterial growth.
What is it?
This is an acute zoonotic disease called Campylobacteriosis, which is causedby a curvedshaped rod bacterium.
This disease is a toxin mediated infection.
Campylobacter jejuni produces a heatliable toxin in the digestive tract liningafter 400 to 500 bacterial cells are ingested.
It is believed that this toxin causes diarrhea.
This disease is the leading cause of diarrhea in the United States, resulting in 4 to 6 million cases each year.
Where is it found?
Animals that commonly carry this disease include healthy cattle, chickens, birds, puppies, kittens, swine, sheep, rodents and flies.
While the animalscarry the organism in their digestive tracts, flies are mechanical vectors.
Mechanical vectors carry microorganisms externally on their bodies.
A fly canspread the disease by picking up microbial “hitchhikers,” on their legs andmouth parts
and deposited these organisms on food and water. Other sourcesof this disease include untreated
drinking water,such as water from springs, streams, rivers and lakes, and raw dairy products.
Prevention
It is thought that most of these illnesses are caused by eating undercooked poultry.
Surveys indicate that 20% to 100% of commercial chickens arecontaminated with Campylobacter.
To prevent this disease:
- Poultry must be cooked throughout to at least 165˚F for 15 seconds to kill this bacterium.
- Sanitize all food contact surfaces after preparation of poultry to prevent crosscontamination to other food.
- Practice good hygiene to prevent the spread of diseases, such as Campylobacter.
- After handling poultry and poultry products, hands need to be lathered with soap
- and washed for 20 seconds in 110˚F water to remove gross debris and microorganisms.
E. coli 0157:H7
What is it?
E. coli (Escherichia coli) is a common bacterial inhabitant of the intestines of all animals, including humans.
It is, in fact, the dominant species of bacteria found in feces,
and is known to have hundreds of strains virtually all of which are harmless, or, in some cases, helpful.
E. coli serotype O157:H7 is a rare variety of E. coli that produces toxins
which are capable of inflicting damage to the lining of the intestine.
The disease is known as hemorrhagic colitis and is caused by an enterohemorrhagic bacterial strain.
This disease was first recognized in theUnited States in 1982.
Escherichia coli 0157:H7 bacteria elaborate toxins inthe digestive tract.
Production of the toxins depends on the presence of certainphage, which are carried by the bacteria.
Phage are viruses that infect bacteriacells. It takes anywhere from 10 to 15 bacterial cells to cause
disease in an individual.
Where is it found?
Cattle are the most important host, and humans may also serve as a reservoirfor human to human transmission.
However, there is increasing evidence that North American deer may also serve as a reservoir as well.
Disease occurs primarily from ingestion of undercooked beef patties, unpasteurized milk,
unpasteurized apple cider, contaminated alfalfa sprouts andperson to person transmission.
Cases have been reported from contaminated drinking water sources and from swimming in a contaminated lake.
Prevention
The primary foods of concern are ground beef, unpasteurized milk and juice and alfalfa sprouts. To prevent illness:
- Cook all ground meat throughout to 155˚F or greater for 15 seconds.
- Care must also be taken to prevent crosscontamination during preparation, storage and transportation.
- Use only pasteurized dairy products and pasteurized juice.
- Wash alfalfa sprouts thoroughly to remove debris and microbes.
What is it?
There are four different species of Shigella that cause the disease named Shigellosis.
These species are sonnei, flexneri, boydii and dysentariae.
Shigellabacteria are nonspore forming rodshaped bacteria that infect the digestive tract of mainly humans,
and in some infections produce an enterotoxin thatmay damage the intestinal lining.
Where is it found?
Humans are the primary source of Shigella and occasionally primates.
Transmission is primarily the fecal/oral route. Most cases are due to poorhygienic practices,
especially the lack of or poor hand washing methods, and water contaminated with human feces.
Prevention
To prevent the spread of diseases such as Shigellosis, great care must be takento wash hands.
The following hand washing procedure must be used before preparing food, before purifying water,
after toilet duty, and afterusing/cleaning the rest room:
- Wash exposed hands, wrists and arms for 20 seconds in
- Warm water (110˚F) with
- Soap all exposed areas to a lather, then
- Rinse soap off and
- Air dry or dry with a paper towel
What is it?
These disease agents are nonmotile, nonspore forming rodshaped bacteria that cause
the disease known as Salmonellosis. There are more than 2000different serotypes of Salmonella.
There is evidence that these bacteria produce an enterotoxin when embedded in the intestinal
lining that maycontribute to disease symptoms.
Where is it found?
Animals that are common carriers of the disease include poultry and swine,
but may also include cattle, rodents, iguanas, turtles, tortoises, terrapins, dogs,cats and humans.
The majority of the cases result from contaminated food and water, improperly cooked poultry
and poultry products, improperlycooked eggs and egg products, improperly pasteurized milk
and milk products, improperly sanitized kitchen surfaces and fecal/oral transmissiondue to improper hand washing.
Prevention
To prevent disease:
- Wash hands thoroughly before handling or preparing food
- Sanitize kitchen surfaces,
- Store raw poultry or poultry products away from other food,
- Cook eggs and egg products to 145˚F for 15 seconds,
- Cook poultry and poultry products to 165˚F for 15 seconds,
- Use pasteurized milk and milk products and
- Store potentially hazardous food cold at 45˚F or less.
Insects such as flies may also be a source of disease by mechanically transporting
disease causing organisms from feces to food and water.
What is it?
Staphylococcus aureus is a circularshaped, nonspore forming bacterium that causes Staphylococcus food poisoning.
These bacteria elaborate a heat stableenterotoxin as they grow and multiple in food.
It is this heat stable toxin thatcauses the symptoms of the illness.
The heat stable toxin once produced in food cannot be destroyed by reheating or cooking.
Where is it found?
Foods that this organism commonly grows on include sandwiches, lunchmeat, salami,
cooked ham, salad dressings, pastries and custards.
Prevention
Education of food handlers is a primary prevention for this disease. Food handlers must follow:
- A strict hand washing regime as described in the Food section of this manual,
- Avoid bare hand contact with readytoeat foods, such as lunchmeat,
- salad dressings, custards and creamfilled pastries,
- Hold potentially hazardous food at proper cold temperatures of 45˚F or less and
- Properly chill hot food to 45˚F within 4 hours
- (However, the use of leftovers by backcountry operators is not recommended
- because of theincreased risk of Staph Food Poisoning).
- Also, food servers with lesions on their hands, wrists, upper arms,
- or faceneed to be restricted and/or excluded from preparing food.
- It is veryimportant that food handlers wear disposable gloves or use utensils when preparing readytoeat foods.
Viruses:
What is it?
The hepatitis A virus is an enterovirus that is part of the Picornaviridae family of viruses.
This virus contains a single strand of RNA (ribonucleic acid)surrounded by a protein capsid
and is about 27 nanometers in size. HepatitisA causes the disease known as Infectious Hepatitis,
which is transmitted by the fecal/oral route, that infects the liver.
Where is it found?
Transmission is mainly through the fecal/oral route and contamination offood and water.
This is why poor sanitation and over crowded conditions maylead to outbreaks of this disease.
Other practices commonly associated with this disease are poor hygienic practices,
improper food handling and poordiaper changing practices at day care facilities.
Prevention
Good sanitation practices are crucial for prevention as well as education for food handlers. It also is essential to:
- Properly treat raw water sources prior to consumption;
- Take care during toilet handling, transportation and clean up;
- Employ proper hand wash procedures as described in the Hygiene section of this manual;
- Cook shellfish to 145˚F for 15 minutes and retain the ShuckerPacker Interstate certificate
- number from the shellfish case for 90 days
- (However, if raw or undercooked shellfish is served to guests,
- then backcountry operators must provide a consumer advisory.
- If thebackcountry operator is catering for an identified “high” risk group or individual,
- then raw or undercooked shellfish may not be served.)
- No bare hand contact with readytoeat food
What is it?
The diseasecausing agent is from a family of Norwalklike viruses that are classified as caliciviruses,
each containing a single strand of RNA and areabout 27 to 32 nanometers in size
(1 nanometer= 1/billionth of a meter).
Where is it found?
There is only one known reservoir and that is humans.
This disease has been identified as the most common cause of nonbacterial gastroenteritis
outbreaks in the United States.
In the United States most outbreaks are linkedwith the consumption of raw or undercooked shellfish.
Other outbreaks have been associated with fecal contamination of food, water and recreationalwater.
The disease is transmitted by the fecal/oral route, and it is believed thathuman to human transmission may occur.
The period of communicability isduring the acute stage of the disease and may last up to 48 hours after diarrhea ends.
Prevention
Prevention guidelines are the same as for Hepatitis A, and they include:
- Proper hand washing;
- Adequate cooking of shellfish to 145˚F for 15 seconds
- (If shellfish is served undercooked or raw then a consumer advisory must be given toguests,
- however, if guests are “high” risk then all shellfish must be adequately cooked);
- Proper treatment of drinking water;
- Proper sanitizing of kitchen and equipment surfaces; and
- Proper storage of raw shellfish to prevent crosscontamination to other food
- No bare hand contact with readytoeat food
