Salmonella bacteria are passed from the feces of people or animals to other people or animals. Contaminated foods are often animal in origin. They include beef, poultry, seafood, milk, or eggs. But all foods, including some unwashed fruits and vegetables, can become contaminated.
Salmonella typhi is the one type of salmonella that lives only in humans. It's passed only from human to human through contaminated food or water. It may cause a serious and life-threatening infection called typhoid fever. Treatment often requires antibiotics. A small number of people who are treated may feel better after treatment. But they will continue to carry the organism and pass it through their feces to others through contaminated food or water.