An American scientist named Daniel E. Salmon is credited with the discovery of the Salmonella family of bacteria in the late 1800s.
Though named for him, it turns out that Salmon was not the true discoverer of Salmonella - a researcher working under him named Theobald Smith actually deserves the credit. Since then, scientists have identified more than 2,400 types of Salmonella bacteria.
Scientists have also figured out where Salmonella live, how they spread to humans, and how to reduce their spread among the general public. Even so, each year about 40,000 cases of salmonellosis are reported in the United States, although many more cases go unreported.
Salmonella bacteria are often found in the feces (poop) of some animals, particularly reptiles. Iguanas, for example, are known to carry Salmonella marina. People who have these animals as pets have a greater risk of contracting salmonellosis because the feces can contaminate a reptile's skin. Then, when people handle the reptiles, they get the bacteria on their hands. As with all type of Salmonella, the risk of contracting salmonellosis can be reduced with careful attention to hand washing.
Other strains of Salmonella can spread to people in foods contaminated with animal feces. This happens when foods such as poultry, eggs, and beef are not processed according to public health standards. Fruit and vegetables can also become contaminated from feces in the soil where they are grown. The bacteria can also be spread through prepared foods if infected food handlers do not properly wash their hands after using the bathroom.
Young children and infants are more likely to become ill from Salmonella because their developing immune systems have a harder time fighting off the infection. Other people at risk for more serious complications include older people, those with weakened immune systems, and people who take cancer drugs, antacids, or stomach acid suppression medication.
In these higher-risk groups, Salmonella is more likely to invade beyond the gastrointestinal tract and cause bacteremia (bacteria in the bloodstream). From there the bacteria can spread deeper into the body and cause more severe symptoms.
Salmonellosis: Illness cause by Salmonella
