From the WebMD Archives
Aug. 2, 2004 — Health officials are reporting that the number of people affected by a recent salmonella outbreak continues to climb. What can you do to prevent salmonella food poisoning?
Last year, a hepatitis outbreak in the U.S. was caused by tainted green onion from Mexico. Officials have linked this year’s food poisoning outbreak from salmonella to certain Roma tomatoes. So far no deaths have been reported.
What Is Salmonella?
Salmonellosis is an infection caused by salmonella bacteria. Salmonella infections are increasing in the U.S. Many types of this bacteria cause disease in animals and people. Recently, a new strain of salmonella was found in the U.S. which poses a major new 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 U.S. 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 weakened immune systems. People with AIDS are particularly vulnerable to salmonellosis — often suffering from recurring episodes. In this group, salmonella infections can be fatal.
Salmonella 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 contained raw meat or meat products can, in turn, become contaminated with the bacteria. This is called cross-contamination.
In the past few 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 such as snakes, turtles, and lizards.
Salmonellosis can become a chronic infection in some people who may not have symptoms. Though they may have no symptoms, infected people 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 laboratory tests show they no longer carry salmonella.
Salmonella has several distinct symptoms:
- Diarrhea
- Fever
- Abdominal cramps
- Headache
In most people, symptoms begin from 12 hours to three days after being infected. These symptoms, along with possible nausea, loss of appetite, and vomiting, usually last for four to seven days. Diarrhea can be severe and require hospitalization. The bacteria usually infect the intestines however it can also infect the blood and produce more severe and life-threatening symptoms such as infection of the heart valves or blood vessels.
Getting Control of Salmonella Poisoning
A health care provider can use laboratory tests to identify salmonella in the stool of an infected person.
Most cases of salmonellosis clear up within five to seven days and don’t require treatment with antibiotics and intravenous fluids. People with severe diarrhea who become dehydrated may need intravenous fluids. If the infection spreads from the intestines into the bloodstream, health care providers can treat it with antibiotics.
Other Possible Problems
While most people recover successfully from salmonella, a few may develop a chronic condition called Reiter’s syndrome. This syndrome can last for months or years and can lead to arthritis. Symptoms include:
- 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 a strain called Salmonella typhi. This disease, which can be fatal if untreated, is not common in the U.S. It is frequently 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 in some parts of the world.
You can prevent salmonella food poisoning by taking some precautions:
- Drink only pasteurized milk.
- Cook poultry, ground beef, and eggs thoroughly before eating.
- Don’t eat or drink foods containing raw eggs or raw unpasteurized milk, 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 poultry products to an internal temperature of 170 degrees Fahrenheit for breast meat and 180 degrees Fahrenheit for thigh meat.
- Wash all food preparation surfaces and utensils that have come in contact with raw poultry or raw eggs with soap and hot water.
- Wash hands immediately after handling raw poultry or raw eggs.
- Wash hands immediately after handling reptiles (turtles, iguanas, lizards) or come in contact with pet feces, since salmonella can be found in the feces of these animals. Even healthy reptiles are likely to harbor salmonella in their intestines.
SOURCE: National Institutes of Health.
