A salmonella infection is a foodborne illness caused by the salmonella bacteria carried by some animals, which can be transmitted from kitchen surfaces and can be in water, soil, animal feces, raw meats, and eggs. Salmonella infections typically affect the intestines, causing vomiting, fever, and other symptoms that usually resolve without medical treatment.
You can help prevent salmonella infections by not serving any raw meat or eggs, and by not keeping reptiles as pets, particularly if you have very young children.
Hand washing is a powerful way to guard against salmonella infections, so it's essential to teach kids to wash their hands, particularly after trips to the bathroom and before handling food in any way.
Not everyone who ingests salmonella bacteria will become ill. Children, especially infants, are the most likely candidates to get sick from it. About 50,000 cases of salmonella infection are reported in the United States each year and about one third of those are in kids 4 years old or younger.
The type of salmonella most commonly associated with infections in humans is called nontyphoidal salmonella. It is carried by chickens, cows, and reptiles such as turtles, lizards, and iguanas.
Another, rarer form of salmonella, typhoidal salmonella (typhoid fever), is carried only by humans and is usually transmitted through direct contact with the fecal matter of an infected person. This kind of salmonella infection can lead to high fever, abdominal pain, headache, malaise, lethargy, skin rash, constipation, and delirium. It occurs primarily in developing countries without appropriate systems for handling human waste.
Signs and Symptoms
A salmonella infection generally causes nausea, vomiting, abdominal cramps, diarrhea (sometimes bloody), fever, and headache. Because many different kinds of illnesses can cause these symptoms, most doctors will take a stool sample to make an accurate diagnosis.
Symptoms of most salmonella infections usually appear within 3 days of contamination and typically go away without medical treatment.
In cases of typhoid fever caused by salmonella bacteria, early symptoms are the same. But in the second week, the liver and spleen can become enlarged, and a distinctive "rose spotted" skin rash may appear. From there, the infection can cause other health problems, like meningitis and pneumonia.
People at risk for more serious complications from a salmonella infection include those who:
- have compromised immune systems (such as people with HIV)
- take cancer-fighting drugs
- have sickle cell disease or an absent or nonfunctioning spleen
- take chronic stomach acid suppression medication
In these higher-risk groups, most doctors will treat an infection with antibiotics to prevent it from spreading to other parts of the body and causing additional health problems.
You have many ways to help prevent salmonella bacteria from making your family sick. Most salmonella bacteria appear in animal products and can be killed by the heat from cooking. So it's important to make sure that you don't serve raw or undercooked eggs, poultry, or meat. Microwaving is not a reliable way to kill the salmonella bacteria.
Because salmonella bacteria can contaminate even intact and disinfected grade A eggs, avoid serving poached eggs or eggs that are served sunny-side up.
Salmonella also can be spread through cross-contamination, so when you're preparing meals, keep uncooked meats away from cooked and ready-to-eat foods. In addition, thoroughly wash your hands, cutting boards, counters, and knives after handling uncooked foods.
Some foods may contain unrecognized raw-food products and should be avoided. Caesar salad dressing, the Italian dessert tiramisu, homemade ice cream, chocolate mousse, eggnog, cookie dough, and frostings can contain raw eggs. Unpasteurized milk and juices also can be contaminated with salmonella.
Fecal matter is often the source of salmonella contamination, so hand washing is extremely important, particularly after using the toilet and before preparing food.
Take care to avoid contact with the feces of family pets — especially reptiles. Wash your hands thoroughly after handling an animal and ensure that no reptiles are permitted to come into contact with an infant. Even healthy reptiles (especially turtles and iguanas) are not appropriate pets for small children and should not be in the same house as an infant.
If your child has a salmonella infection and a healthy immune system, your doctor may let the infection pass without treatment. But any time your child develops a fever, headache, or bloody diarrhea, call the doctor to rule out any other problems.
If your child is infected and has a fever, you may want to give acetaminophen to reduce his or her temperature and relieve cramping. As with any infection that causes diarrhea, it's important to give your child plenty of liquids to avoid dehydration.
Reviewed by: Joel Klein, MD
Date reviewed: October 2008