Foodborne Illness

Foodborne Illness

Foodborne illness generally refers to illnesses caused by microorganisms consumed by eating any type of food. When people complain of "food poisoning," they may actually have been exposed to the microorganisms that cause foodborne illness. Microbes, bacteria and pathogens are other terms used to describe the microorganisms that cause foodborne illness.

Government officials and health experts consistently rate foodborne illnesses as the greatest food safety threat. Their effects can range from relatively minor discomfort to more serious symptoms and manifestations such as fever, diarrhea, dehydration and even death. The acute illnesses posed by foodborne organisms, coupled with the ease and swiftness with which they develop, present food safety challenges for the entire food distribution chain, including producers, packers and shippers, processors and manufacturers, retailers and consumers.

Illness Estimates

Government estimates vary widely as to the prevalence and growth of foodborne illnesses. Since many people afflicted with foodborne illnesses assume they have the flu and do not visit a physician, cases tend to be underreported. The Centers for Disease Control and Prevention, the federal agency that collects and disseminates information on foodborne illnesses, notes that reports of outbreaks represent "only a small fraction of the total number that occur."

There are five basic categories of foodborne illness agents:

Bacteria - Some bacteria, of course, are beneficial and are even used in food processing; others combat disease. However, bacteria account for more than two-thirds of all outbreaks of foodborne illness in the United States. There are literally thousands of different strains of bacteria that can cause foodborne disease; fewer than 50 to 100 are responsible for most of the illnesses.
Viruses - Viruses are too small to be seen with any ordinary microscope, and they grow or reproduce only in living cells. They are often found in untreated water. In addition, viruses from human feces on inadequately washed hands can be a source of foodborne disease.
Parasites - Food and water can carry such parasites as tapeworms, roundworms and certain species of protozoa.
Food toxins - Toxins, such as scombrotoxin and ciguatoxin, are formed by microorganisms in food when stored at improper temperatures.
Unknown - Statistically, most foodborne illnesses are classified as "unknown," because frequently no laboratory analysis is ever conducted to verify the specific agent or cause.

Foodborne illnesses occur when contaminants cause either infections or intoxications. Infections result from the ingestion of significant quantities of contaminants that have reproduced in the food itself, or in the small intestines once consumed.

It is important to emphasize that since there are literally thousands of different strains of bacteria that can cause foodborne disease, it is difficult to generalize on their characteristics and effects. For instance, most bacterial cells are destroyed by thorough cooking, yet some can survive boiling. Most microorganisms prefer warm environments, but some such as listeria will survive and even grow at refrigerator temperatures. Most micro-organisms do not survive food with relatively high salt concentrations, but some will.

Major Foodborne Illnesses

Four types of bacteria are responsible for most of the reported cases of foodborne illness:

Salmonellosis - Salmonellosis is the most common bacterial foodborne illness. The salmonella family includes about 2,000 different strains of bacteria, but only ten strains cause most of the reported salmonella infections. Salmonella can be found on, and ingested from, a variety of sources, but is most frequently associated with poultry, meat, eggs and unpasteurized milk.
Botulism - Cases of botulism are rare but very dangerous. They are usually associated with low-acid canned foods, such as meats and vegetables that have been improperly processed or stored.
Staphylococcal (Staph) - These bacteria is carried by humans in the nose and throat areas and in skin infections. Staph toxins are not killed by ordinary cooking, which is why personal hygiene is so important in the kitchen.
Clostridium perfringens - These are bacteria present throughout the environment, growing where there is little or no oxygen. Foods in buffets and casseroles, stews and gravies must be maintained at 140 degrees Fahrenheit or above or they will be particularly susceptible to growth of this bacterium.

More recently attention has been focused on the tragic loss of life from E.coli 0157:H7. The 0157:H7 is a rare strain of E.coli that produces large quantitites of a potent toxin that forms in and causes severe damage to the lining of the intestine. The disease produced by it is called Hemorrhagic Colitis.

E. coli 0157:H7 survive refrigerator and freezer temperatures. Once they get in food, they can multiply very slowly at temperatures as low as 44Ź F. The actual infectious dose is unknown, but most scientists believe it takes only a small number of this strain of E. coli to cause serious illness and even death, especially in children. It is killed by thorough cooking.

At least four factors are necessary for bacterial foodborne illness to occur: 1) a microbial contaminant; 2) a food vehicle; 3) conditions allowing bacteria to survive, reproduce or form a toxin; and 4) a vulnerable food consumer who ingests enough of the agent.

Where Does Foodborne Illness Come From?

Bacteria, viruses and other microorganisms are found widely throughout nature and the environment. An average person carries more than 150 kinds of bacteria inside and outside the body. Generally, the bacteria can spread easily and rapidly, requiring just food, moisture, a favorable temperature and time to multiply. Therefore, animal protein foods - meat, eggs, poultry and fish - are common hosts of foodborne bacteria. However, bacteria can be readily spread from a non-food item - such as a knife, crate, cutting board, or human hands - to food.

Contaminants causing foodborne illness can originate within the food living in an animal, on the food (egg shell or produce), from unsafe water, or from human or animal feces. In the home, favorite bacteria hiding places include sponges, dish towels, aprons, cutting boards, sinks, counter tops and wooden utensils.

Symptoms of Foodborne Illness

Since foodborne illness can potentially cause severe illness or death, people who suspect they have become sick from food should see a doctor. Symptoms include severe abdominal cramps, diarrhea (often bloody), vomiting and nausea, dry mouth, double vision, difficulty swallowing and flu-like symptoms (fever, chills, headache, backache). Symptoms may appear from 12 hours to ten days after exposure.

Vulnerable Groups

Certain segments of the population face greater risks and have a higher incidence of foodborne illness:

Older people - Ability to fight foodborne disease lessens with age. As people grow older, their stomachs produce less acid (which destroys bacteria) and their kidneys are less able to filter bacteria from the blood. The elderly, the fastest growing segment of the population, is the largest high-risk group.
Pregnant women/infants - Some illnesses that an expectant mother contracts can affect her fetus. Unborn babies do not have a fully developed immune system and therefore cannot effectively fight bacteria. Foodborne illness can cause spontaneous abortions and stillbirths. In addition, foodborne illness can lead to urinary tract infections, meningitis and kidney failure in infants.
People with diabetes, AIDS, cancer or on chemotherapy - These individuals have weakened immune systems and are also more vulnerable to foodborne illness. For people suffering from a chronic illness, foodborne illness can be especially difficult to treat, may recur and may interfere with treatment for other illnesses.

How to Prevent Foodborne Illness

Congress and federal agencies are examining ways to improve the meat inspection and producing systems from farm to table to help reduce the risk of foodborne illness. Yet even with such improvements, consumers must take the necessary steps to avoid food contamination.

Public health experts believe unsanitary food preparation practices are major contributors to outbreaks. Errors made in shopping for, transporting, storing, preparing or serving food can enable bacteria to survive and grow. If foods are prepared a day or more before consumption and food handlers are careless, the chance of illness can increase because bacteria have more time to multiply.

The U.S. Department of Agriculture offers the following food handling tips:

Don't buy cans or glass jars with dents, cracks or bulging lids.
Never eat raw meat, poultry, seafood or eggs.
Cook raw food thoroughly - to at least 160 degrees Fahrenheit - to kill any bacteria present.
Thoroughly reheat leftovers.
Promptly refrigerate cooked meat and poultry in small shallow containers. Remove stuffing and refrigerate separately.
Refrigerate perishable food as soon as you get home from the market.
Store canned goods in a cool, dry place for use within a year. Never put them above the stove or in a damp area.
Don't thaw food on the counter; bacteria grow quickly at room temperature. Thaw food in the refrigerator or in the microwave just before cooking.
Keep work areas clean. Wash hands, utensils and cutting boards in hot soapy water before preparing food and after handling raw meat or poultry.
Use a plastic cutting board instead of a wooden one when cutting raw meat or poultry.
Keep pets away from food, cooking and eating surfaces, and equipment. Don't count on cooking or refrigeration to "fix" a mistake.
Don't take chances - if you suspect there's a problem, throw the food out.

Irradiation: A Missed Opportunity?

Irradiation is a technology that was developed some 60 years ago and gained its first approval from the federal government for commercial use in the mid-1960s. Today, it is used routinely in the medical and packaging industries to sterilize a variety of organic and synthetic materials.

At its inception, however, scientists also foresaw a wide variety of irradiation applications for food products, particularly in combating dangerous microbial foodborne diseases. Federal officials project that it could be used to eliminate pathogens in ten to 40 percent of the foods in our diet. Yet despite the technology's acceptance as a food safety aid in more than 30 nations internationally, it is used on a very limited basis today in the United States.

The reason for the holdup can be summed up in one word: radiation. Even though irradiation does not cause foods to become radioactive and leaves no radioactive "residues," the public's fear of radiation is very strong. Without consumer support, processors will not use the process.

With foodborne disease on poultry, seafood and other commodities a concern, the failure to employ this proven technology seems, at best, a missed opportunity and, at worst, a sad example of how fear and ignorance can - even during modern times - still drive decisions about food and food safety.

Go to the HIV & Nutrition Menu

Go to the HIVpositive.us Main Menu

09197-