May 15, 2025 | Recent outbreaks have led to renewed interest in salmonella, a bacterium that commonly contaminates raw poultry, eggs, beef, and sometimes unwashed fruit and vegetables. The Food and Drug Administration issued a recall for tomatoes in 14 states due to a potential contamination risk while the Centers for Disease Control and Prevention announced earlier this month that at least seven people were infected with the bacteria due to an outbreak in numerous states related to backyard poultry. The CDC estimates that salmonella cause about 1.35 million infections in the U.S. every year, most of them due to contaminated food. The bacterial genus is named after Daniel Elmer Salmon, an American veterinarian who spent his career studying animal diseases for the U.S. Department of Agriculture. The first strain, salmonella choleraesuis, was discovered by Theobald Smith, Salmon’s research assistant. Since then, more than 2,500 subtypes have been identified.

May 15, 2025 | Salmonella infection, a condition known as 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. Some people with salmonella infection have no symptoms. Most people develop diarrhea, fever and stomach cramps within eight to 72 hours after exposure. Most healthy people recover within a few days to a week without specific treatment. In some cases, diarrhea can cause severe dehydration and requires prompt medical attention. Life-threatening complications also may develop if the infection spreads beyond the intestines. The risk of getting a salmonella infection, including varieties that cause typhoid fever, is higher with travel to countries without clean drinking water and proper sewage disposal.

May 15, 2025 | Salmonella bacteria live in the intestines of people, animals and birds. Most people are infected with salmonella by consuming food or water that has been contaminated by feces. Raw meat and poultry can become contaminated during the butchering process while seafood can be contaminated if harvested from infected water. Some fresh produce, particularly imported varieties, may be irrigated in the field or washed during processing with water contaminated with salmonella. Contamination can also occur in the kitchen, when juices from raw meat and poultry come into contact with uncooked foods, such as salads. Many foods become contaminated when prepared by people who don’t wash their hands thoroughly after using the toilet or changing a diaper or after handling contaminated food. Infection can also occur if people touch something that is contaminated and then put their fingers in their mouths.

May 15, 2025 | The 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. Antacids, for example, lower the stomach’s acidity and allow more salmonella bacteria to survive. Inflammatory bowel disease damages the lining of the intestines, which makes it easier for salmonella bacteria to take hold. And the recent use of antibiotics can reduce the number of “normal” bacteria in a person’s intestines, which may impair their ability to fight off an infection. Some medical problems or medications appear to increase your risk of catching salmonella by weakening your immune system. This interferes with your body’s ability to fight infection and disease. Some examples of these include sickle cell disease and malaria along with corticosteroids and anti-rejection drugs taken after organ transplants.

May 15, 2025 | A 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. Dehydration can occur if the patient doesn’t drink enough to replace the fluid lost due to diarrhea. The warning signs of dehydration include urinating less than usual or dark-colored urine, a dry mouth and tongue, being more tired than usual and irritability or confusion. If a salmonella infection enters your bloodstream, a condition known as bacteremia, it can infect tissues throughout the body, including the lining of the heart. People who have had a salmonella infection are at increased risk of developing reactive arthritis, also known as Reiter’s syndrome. The symptoms of reactive arthritis can include eye irritation, painful urination and pain in the joints.