Foodborne Diseases
Jonathan Wood
Overview
Infectious diseases spread through food or beverages are a common, distressing, and sometimes life-threatening problem for millions of people in the United States and around the world. The Centers for Disease Control and Prevention (CDC) estimates 76 million people suffer foodborne illnesses each year in the United States, accounting for 325,000 hospitalizations and more than 5,000 deaths.
Foodborne disease is extremely costly. Health experts estimate that the yearly cost of all foodborne diseases in this country is 5 to 6 billion dollars in direct medical expenses and lost productivity. Infections with the bacteria Salmonella alone account for $1 billion yearly in direct and indirect medical costs.
There are more than 250 known foodborne diseases. They can be caused by bacteria, viruses, or parasites. Natural and manufactured chemicals in food products also can make people sick. Some diseases are caused by toxins (poisons) from the disease-causing organism (germ), others by bodily reactions to the organism itself. People infected with foodborne germs may have no symptoms or develop symptoms ranging from mild intestinal discomfort to severe dehydration and bloody diarrhea.
Recently, public health, agriculture, and environmental officials have expressed growing concern over keeping the nation's food and water supply safe from terrorist acts. This bioterrorism threat is being studied by a number of U.S. agencies, including CDC, Food and Drug Administration (FDA), Department of Agriculture, Environmental Protection Agency, and National Institutes of Health.
This fact sheet describes five foodborne diseases caused by bacteria.
E. coli infection
Campylobacter infection
Salmonella infection
Shigella infection
Botulism
PREVENTING FOODBORNE DISEASES
Many times, foodborne diseases are easy to avoid. These are some basic ways to prevent being infected by most foodborne germs.
Wash hands carefully before preparing food.
Wash hands, utensils, and kitchen surfaces with hot soapy water after they touch raw meat or poultry.
Cook beef and beef products thoroughly, especially hamburger.
Cook poultry and eggs thoroughly.
Eat cooked food promptly and refrigerate leftovers within 2 hours after cooking.
Wash fruits and vegetables thoroughly, especially those that will be eaten raw.
Drink only pasteurized milk and juices and treated surface water.
Wash hands carefully after using the bathroom, changing infant diapers, or cleaning up animal feces.
Ways to avoid getting sick from specific foodborne germs are described in the following sections on foodborne diseases.
Specific Diseases
E. COLI INFECTION
Certain types of Escherichia coli bacteria, commonly called E. coli, can cause foodborne illness.
Harmless strains of E. coli can be found widely in nature, including the intestinal tracts of humans and warm-blooded animals. Disease-causing strains, however, are a frequent cause of both intestinal and urinary-genital tract infections.
Several different strains of harmful E. coli can cause diarrheal disease. A particularly dangerous type is called enterohemorrhagic E. coli, or EHEC. EHEC often causes bloody diarrhea and can lead to kidney failure in children or people with weakened immune systems.
In 1982, scientists identified the first dangerous strain in the United States. The type of harmful E. coli most commonly found in this country is named O157:H7, which refers to chemical compounds found on the bacterium's surface. This type produces one or more related, powerful toxins which can severely damage the lining of the intestines.
Other types, including O26:H11 and O111:H8, also have been found in this country and can cause human disease.
Cattle are the main sources of E. coli O157:H7, but other domestic and wild mammals also can harbor these bacteria.
Transmission
E. coli bacteria and its toxins have been found in
Undercooked or raw hamburgers
Salami
Alfalfa sprouts
Lettuce
Unpasteurized milk, apple juice, and apple cider
Contaminated well water
Unsuspecting swimmers have been infected by accidentally swallowing unchlorinated or underchlorinated water in swimming pools contaminated by human feces. You also can get infected by swimming in sewage-contaminated water.
Symptoms
E. coli O157:H7 toxin can damage the lining of your intestine and cause other symptoms including
Nausea
Severe abdominal cramps
Watery or very bloody diarrhea
Tiredness
You might develop low-grade fever or vomiting. Symptoms usually begin from 2 to 5 days after eating contaminated food and may last for 8 days.
Other types of E. coli can cause diarrheal disease
Enterotoxigenic E. coli (ETEC), which produce a toxin similar to Cholera toxin, can cause diarrhea. These strains typically cause so-called travelers diarrhea because they commonly contaminate food and water in developing countries.
Enteropathogenic E. coli (EPEC) are associated with persistent diarrhea (lasting 2 weeks or more) and are more common in developing countries where they can be transmitted by contaminated water or contact with infected animals. Health experts do not know how much disease some of these other types of E. coli cause in the United States.
Diagnosis
Your health care provider can use laboratory tests to identify E. coli in your stool if you are infected.
Treatment
If you are like most people infected with E. coli O157:H7, you will recover within 5 to10 days without treatment. Antibiotics are usually not helpful, and health care experts recommend against taking antidiarrheal medicines.
Prevention
Eat only thoroughly cooked beef and beef products.
Cook ground beef patties to an internal temperature of 160 degrees Fahrenheit.
Avoid unpasteurized juices.
Drink only pasteurized milk.
Wash fresh fruits and vegetables thoroughly before eating raw or cooked.
Complications
Hemolytic uremic syndrome (HUS), a serious complication of EHEC, can lead to kidney failure. In North America, HUS is the most common cause of acute kidney failure in children, who are particularly prone to this complication. This life-threatening condition is usually treated in an intensive care unit of a hospital, sometimes with blood transfusions and kidney dialysis.
CAMPYLOBACTERIOSIS
Campylobacteriosis is an infectious disease caused by Campylobacter bacteria. Campylobacter jejuni, C. fetus, and C. coli are the types that usually cause campylobacteriosis in people. C. jejuni causes most cases of the illness.
According to CDC, C. jejuni is the leading cause of bacterial diarrheal illness in the United States, affecting an estimated 2.4 million people every year. The bacteria cause between 5 and 14 percent of all diarrheal illness worldwide. C. jejuni primarily affects children less than 5 years old and young adults (15 to 29 years old). Health care providers report more than 10,000 cases to CDC yearly. In the United States, few people die from Campylobacter infection.
Transmission
You can get infected from handling raw poultry, eating undercooked poultry, drinking nonchlorinated water or raw milk, or handling infected animal or human feces. Most frequently, poultry and cattle waste are the sources of the bacteria, but feces from puppies, kittens, and birds also may be contaminated.
Symptoms
If you are infected with Campylobacter, however, you may have no symptoms. If you do, they may include
Diarrhea (often bloody)
Abdominal cramping and pain
Nausea and vomiting
Fever
Tiredness
Campylobacteriosis usually lasts for 2 to 5 days, but in some cases as long as 10 days. Rarely, some people have convulsions with fever or meningitis.
Diagnosis
A health care provider can use laboratory tests to identify Campylobacter in your stool if you are infected.
Treatment
Most people infected with Campylobacter will get better with no special treatment. If you need treatment, your health care provider can prescribe an antibiotic such as ciprofloxacin or azithromycin.
Erythromycin helps treat diarrhea caused by Campylobacter. If you have diarrhea, be sure to drink plenty of water.
Prevention
Wash hands before preparing food.
Wash hands immediately after handling raw poultry or other meat.
Wash thoroughly with soap and hot water all food preparation surfaces and utensils that have come in contact with raw meat.
Cook poultry products to an internal temperature of 170 degrees Fahrenheit for breast meat and 180 degrees Fahrenheit for thigh meat.
Drink pasteurized milk and chlorinated or boiled water.
Wash hands after handling pet feces or visiting zoos and petting zoos.
Complications
Some people infected with Campylobacter develop arthritis. A small number of people with campylobacteriosis may develop Guillain-Barré Syndrome (GBS), the leading cause of acute paralysis in this country. This rare condition develops from 2 to 4 weeks after Campylobacter infection and usually after diarrheal symptoms have disappeared. People with GBS suffer from increasing paralysis of the limbs which lasts for several weeks. In more severe cases, they develop breathing problems requiring very long hospital stays.
SALMONELLOSIS
Salmonellosis, or salmonella, is an infection caused by Salmonella bacteria. Salmonella infections are increasing in the United States. Many types of this bacteria cause disease in animals and people.
While the occurrence of different types of Salmonella varies from country to country, Salmonella typhimurium and S. enteritidis are the two most commonly found in the United States.
An antibiotic-resistant strain of S. typhimurium, called Definitive Type 104 (DT104), was first found in the United Kingdom and then in the United States. It is the second most common strain (after S. enteritidis) of Salmonella found in humans. This strain poses a major threat because it is resistant to several antibiotics normally used to treat people with Salmonella infections.
Salmonellosis may occur in small, contained outbreaks in the general population or in large outbreaks in hospitals, restaurants, or institutions for children or the elderly. While the disease is found worldwide, health experts most often report cases in North America and Europe. Every year, CDC receives reports of 40,000 cases of salmonellosis in the United States. The agency estimates that 1.4 million people in this country are infected, however, and that 1,000 people die each year with salmonellosis. Symptoms are most severe in the elderly, infants, and people with chronic conditions. People with AIDS are particularly vulnerable to salmonellosis-often suffering from recurring episodes.
Transmission
Salmonella bacteria can be found in food products such as raw poultry, eggs, and beef, and sometimes on unwashed fruit. Food prepared on surfaces that previously were in contact with raw meat or meat products can, in turn, become contaminated with the bacteria. This is called cross-contamination.
In recent years, CDC has received reports of several cases of salmonellosis from eating raw alfalfa sprouts grown in contaminated soil. Salmonella infection frequently occurs after handling pets, particularly reptiles like snakes, turtles, and lizards.
Salmonellosis can become a chronic infection in some people who may not have symptoms. Though they may have no symptoms, they can spread the disease by not washing their hands before preparing food for others. In fact, health care experts recommend that people who know they have salmonellosis not prepare food or pour water for others until a laboratory tests show they no longer carry Salmonella bacteria.
Symptoms
The following symptoms usually begin from 12 hours to 3 days after you are infected.
Diarrhea
Fever
Abdominal cramps
Headache
These symptoms, along with possible nausea, loss of appetite, and vomiting, usually last for 4 to 7 days. Diarrhea can be severe and require hospitalization.
Diagnosis
Your health care provider can use laboratory tests to identify Salmonella in your stool if you are infected.
Treatment
If you are like most people infected with Salmonella, your infection will clear up within 5 to 7 days and you won't need to be treated. If you have severe diarrhea, however, you may need intravenous fluids. If the infection spreads from the intestines into the bloodstream, your health care provider can treat it with antibiotics such as ampicillin.
Prevention
Drink only pasteurized milk.
Don't eat foods containing raw eggs, such as homemade caesar salad dressing, cookie dough, and hollandaise sauce, or drink homemade eggnog made with raw eggs.
Handle raw eggs carefully.
* Keep eggs refrigerated.
* Throw away cracked or dirty eggs.
Cook eggs thoroughly.
Cook poultry products to an internal temperature of 170 degrees Fahrenheit for breast meat and 180 degrees Fahrenheit for thigh meat.
Wash thoroughly with soap and hot water all food preparation surfaces and utensils that have come in contact with raw poultry or raw eggs.
Wash hands immediately after handling raw poultry or raw eggs.
Wash hands immediately after handling reptiles or contact with pet feces.
Complications
While most people recover successfully from salmonellosis, a few may develop a chronic condition called Reiter's syndrome. This syndrome can last for months or years and can lead to arthritis. Its symptoms are
Painful joints
Irritated eyes
Painful urination Unless treated properly, Salmonella can escape from the intestine and spread by blood to other organs, sometimes leading to death.
Typhoid fever, a more serious disease, results from infection with S. typhi. This disease, which can be fatal if untreated, is not common in the United States. Typhoid fever frequently is found in developing countries, usually in contaminated water. It's also a risk in areas where flooding or earthquakes cause sewer systems to overflow. Appropriate antibiotics are usually effective for treating typhoid fever, although the incidence of antibiotic-resistant S. typhi is increasing is some parts of the world.
SHIGELLOSIS
Shigellosis, also called bacillary dysentery, is an infectious disease caused by Shigella bacteria. Four main types of Shigella cause infection: Shigella dysenteriae, S. flexneri, S. boydii, and S. sonnei. CDC estimates that more than 400,000 cases occur every year in the United States. Health care providers report about 18,000 cases to CDC each year.
Transmission
You can be infected from foodborne Shigella by
Eating food or drinking beverages contaminated by food handlers infected with Shigella who didn't wash their hands properly after using the bathroom
Eating vegetables grown in fields containing sewage
Eating food contaminated by flies which were bred in infected feces
Drinking or swimming in contaminated water
S. sonnei is the most common type of Shigella in developed countries, including the United States. Outbreaks of shigellosis frequently occur in tropical or temperate climates, especially in areas with severe crowding and/or poor hygiene that sometimes occur in day care and institutional settings.
Even if you have no symptoms of shigellosis, you can still pass the bacteria to others. An extremely low number of bacteria (10 to 100) is needed to transmit the infection. Therefore, it is commonly transmitted by food service workers who are sick or infected, but have no symptoms, and who do not properly wash their hands after using the toilet. If you know you have shigellosis, you should not prepare food or pour water for others until laboratory tests show you no longer carry Shigella bacteria.
Symptoms
Fever
Tiredness
Watery or bloody diarrhea
Nausea and vomiting
Abdominal pain
Symptoms usually begin within 2 days after being exposed to Shigella. Symptoms usually are gone within 5 to 7 days.
Treatment
If you have a mild infection, you should get better quickly, without taking medicine. If you need to be treated, your health care provider usually will prescribe an antibiotic such as ampicillin or ciprofloxacin. Antidiarrheal medicines may make the illness worse.
S. flexneri infection can progress to Reiter's syndrome which can last for months or years and can lead to chronic arthritis. Its symptoms are
Painful joints
Irritated eyes
Painful urination Prevention
Wash hands thoroughly with soap and water before preparing foods and beverages.
Wash hands thoroughly after using the bathroom or changing infant diapers.
Disinfect diaper-changing areas after use.
Help young children wash their hands carefully after they use the bathroom.
Avoid swallowing swimming pool water.
Complications
People who have diarrhea symptoms usually recover completely, although their bowel habits may not return to normal until several months later. S. dysenteriae type 1 produces Shiga toxin and can lead to life-threatening hemolytic uremic syndrome (HUS), the same complication that develops in some cases of infection with E. coli bacteria (enterohemorrhagic E. coli or EHEC).
BOTULISM
Botulism is a rare but serious illness. Each year, U.S. health care providers report an average of 110 cases of food, infant, and wound botulism to Centers for Disease Control and Prevention (CDC). About 10 to 30 outbreaks of foodborne botulism are reported annually.
Although this illness does not occur frequently, it can be fatal if not treated quickly and properly. This fact sheet will focus on botulism caused by eating contaminated food.
Infectious diseases spread through food or beverages are a common, distressing, and sometimes life-threatening problem for millions of people in the United States and around the world. CDC estimates 76 million people suffer foodborne illnesses each year in the United States, accounting for 325,000 hospitalizations and more than 5,000 deaths.
Foodborne disease is extremely costly. Health experts estimate that the yearly cost of all foodborne diseases in this country is 5 to 6 billion dollars in direct medical expenses and lost productivity.
There are more than 250 known foodborne diseases. They can be caused by bacteria, viruses, or parasites. Natural and manufactured chemicals in food products also can make people sick. Some diseases are caused by toxins (poisons) from the disease-causing microbe (germ), others by the human body's reactions to the microbe itself.
To better understand the epidemiology (study of disease origin and spread) of foodborne diseases in the United States, 10 states across the country are collecting annual data on the occurrence of new cases of the most common causes of bacterial and parasitic infections through the Foodborne Diseases Active Surveillance Network, a CDC-sponsored program known as FoodNet (www.cdc.gov/foodnet ).
Recently, public health, agriculture, and environmental officials have expressed growing concern about keeping the nation's food and water supply safe from terrorist acts. A number of U.S. agencies, including the National Institutes of Health, CDC, Food and Drug Administration (FDA), U.S. Department of Agriculture, and U.S. Environmental Protection Agency, are studying this bioterrorism threat.
CAUSE
Botulism is caused by toxin produced by Clostridium botulinum bacteria. This toxin affects your nerves and, if untreated, can cause paralysis and respiratory failure. C. botulinum toxin is one of the most powerful toxins known in nature. Exposure to the toxin, particularly in an aerosolized (spray) form, can be fatal. C. botulinum has been made into weapons by rogue states and is a focus of current efforts to counter bioterrorism.
Transmission
Often, cases of foodborne botulism come from home-canned foods with low acid content, such as asparagus, green beans, beets, and corn. C. botulinum is anaerobic, which means it can survive and grow with little or no oxygen. Therefore, it can live very well in sealed containers. Outbreaks of the infection, however, are often from more unusual sources such as chili peppers, tomatoes, and improperly handled baked potatoes wrapped in aluminum foil.
Symptoms
Double vision and drooping eyelids
Slurred speech
Dry mouth and difficulty swallowing
Weak muscles
Symptoms of foodborne botulism usually begin within 18 to 36 hours after you eat contaminated food, but can occur in as few as 6 hours or as much as 10 days afterward.
Diagnosis
A health care provider can use laboratory tests to identify C. botulinum toxin in your blood or stool if you are infected.
Treatment
If you are diagnosed early, your health care provider can treat foodborne botulism successfully with an antitoxin that blocks the action of the bacterial toxin circulating in your blood. Although antitoxin keeps the disease from becoming worse, it will still take many weeks before you recover. Your health care provider may try to remove any contaminated food still in your gut by making you vomit or by giving you an enema.
Prevention
Follow strict hygienic steps when home canning.
Refrigerate oils containing garlic or herbs.
Keep baked potatoes wrapped in aluminum foil either hot until served or refrigerated.
Consider boiling home-canned food before eating it to kill any bacteria lurking in the food.
Complications
If left untreated, this illness can cause paralysis of the arms, legs, trunk, and the muscles that help you breathe. The paralysis usually improves slowly over several weeks. People who develop severe botulism experience breathing failure and paralysis and need to be put on ventilators (breathing machines).
**Reprinted from NIH Fact-Sheets dated February 2005, July 2006, and August 2006