Salmonella infection 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 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:
- Raw meat, poultry and seafood. Feces may get onto raw meat and poultry during the butchering process. Seafood may be contaminated if harvested from contaminated water.
- Raw eggs. While an egg’s shell may seem to be a perfect barrier to contamination, some infected chickens produce eggs that contain salmonella before the shell is even formed. Raw eggs are used in homemade versions of mayonnaise and hollandaise sauce.
- Fruits and vegetables. Some fresh produce, particularly imported varieties, may be hydrated in the field or washed during processing with water contaminated with salmonella. Contamination also can occur in the kitchen, when juices from raw meat and poultry come into contact with uncooked foods, such as salads.
The U.S. 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, then put your fingers in your mouth.
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 gastroenteritis. Possible signs and symptoms include:
- Abdominal cramps
- Blood in the stool
Signs and symptoms of salmonella infection generally last four to seven days, although it may take several months for your bowels to return to normal.
A few varieties of salmonella bacteria result in typhoid fever, a sometimes deadly disease that is more common in developing countries.