Salmonella infection (salmonellosis) is a common bacterial disease that affects the intestinal tract. Salmonella bacteria typically live in animal and human intestines and are shed through feces. Humans become infected most frequently through contaminated water or food.
Typically, people with salmonella infection have no symptoms. Others develop diarrhea, fever and abdominal cramps within eight to 72 hours. Most healthy people recover within a few days without specific treatment.
In some cases, the diarrhea associated with salmonella infection can be so dehydrating as to require prompt medical attention. Life-threatening complications also may develop if the infection spreads beyond your intestines. Your risk of acquiring salmonella infection is higher if you travel to countries with poor sanitation.
Salmonella infection is usually caused by eating raw or undercooked meat, poultry, eggs or egg products. The incubation period ranges from several hours to two days. Most salmonella infections can be classified as stomach flu (gastroenteritis). Possible signs and symptoms include:
Signs and symptoms of salmonella infection generally last two to seven days. Diarrhea may last up to 10 days, although it may take several months before bowels return to normal.
A few varieties of salmonella bacteria result in typhoid fever, a sometimes deadly disease that is more common in developing countries.
Salmonella bacteria live in the intestines of people, animals and birds. Most people are infected with salmonella by eating foods that have been contaminated by feces. Commonly infected foods include:
The Food and Drug Administration also indicates that some salmonella outbreaks have been traced to contaminants in spices. The agency is seeking ways to increase the safety of spices.
Many foods become contaminated when prepared by people who don't wash their hands thoroughly after using the toilet or changing a diaper. Infection also can occur if you touch something that is contaminated, including pets, especially birds and reptiles, and then put your fingers in your mouth.
Factors that may increase your risk of salmonella infection include activities that may bring you into closer contact with salmonella bacteria and health problems that may weaken your resistance to infection in general.
Your body has many natural defenses against salmonella infection. For example, strong stomach acid can kill many types of salmonella bacteria. But some medical problems or medications can short-circuit these natural defenses. Examples include:
The following medical problems or medications appear to increase your risk of contracting salmonella by impairing your immune system.
Salmonella infection usually isn't life-threatening. However, in certain people — especially infants and young children, older adults, transplant recipients, pregnant women, and people with weakened immune systems — the development of complications can be dangerous.
If you can't drink enough to replace the fluid you're losing from persistent diarrhea, you may become dehydrated. Warning signs include:
If salmonella infection enters your bloodstream (bacteremia), it can infect tissues throughout your body, including:
People who have had salmonella are at higher risk of developing reactive arthritis. Also known as Reiter's syndrome, reactive arthritis typically causes:
The Department of Agriculture has created a Salmonella Action Plan, which involves updating the poultry slaughter inspection system and enhancing sampling and testing programs for poultry and meat. The plan's purpose is to cut the number of salmonella infections in the United States.
You can also take care to avoid spreading bacteria to others. Preventive methods are especially important when preparing food or providing care for infants, older adults and people with weakened immune systems. Be sure to cook food thoroughly and refrigerate or freeze food promptly.
Washing your hands thoroughly can help prevent the transfer of salmonella bacteria to your mouth or to any food you're preparing. Wash your hands after you:
To prevent cross-contamination:
Cookie dough, homemade ice cream and eggnog all contain raw eggs. If you must consume raw eggs, make sure they've been pasteurized.
Salmonella infection can be detected by testing a sample of your stool. However, most people have recovered from their symptoms by the time the test results return.
If your doctor suspects that you have a salmonella infection in your bloodstream, he or she may suggest testing a sample of your blood for the bacteria.
Because salmonella infection can be dehydrating, treatment focuses on replacing fluids and electrolytes. Severe cases may require hospitalization and fluids delivered directly into a vein (intravenous). In addition, your doctor may recommend:
Even if you don't need medical attention for your salmonella infection, you need to take care not to dehydrate, a common concern with diarrhea and vomiting. Adults should drink water or suck on ice chips. For children, you can use an oral rehydration solution, such as Pedialyte, unless your doctor advises otherwise.
Most people don't need to seek medical attention for a salmonella infection because it clears up on its own within a few days. However, in cases involving infants, young children, older adults and people with weakened immune systems, call your doctor if the illness lasts more than a few days, is associated with high fever or bloody stools, or appears to be causing dehydration.
If you make an appointment with your doctor, it's a good idea to prepare for it. Here's some information to help you.
Preparing a list of questions for your doctor will help you make the most of your time together. For salmonella infection, some basic questions to ask your doctor include:
Don't hesitate to ask any other questions.
Your doctor will need to know:
To prevent dehydration, drink water or suck on ice chips. To prevent dehydration in children, use an oral rehydration solution, such as Pedialyte, unless your doctor advises otherwise.
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