Salmonella spp. are a leading cause of foodborne disease in humans worldwide. While gastroenteritis is the most common presentation in healthy adults, systemic disease can also occur, particularly in those who are immunocompromised including children and the elderly. Focal extraintestinal infections can also be seen. Salmonellosis is generally self-limiting in healthy people, although long term side effects can occur.

In animals, Salmonella spp. primarily cause enteritis and septicemia; however, many species carry the bacterium asymptomatically and shed it in their feces. Ingestion of contaminated animal products, such as eggs, poultry, pork, and other meats is a major route of transmission in humans. Outbreaks associated with nonanimal foods, such as fresh produce and peanut butter, have been increasingly reported in recent years. Direct contact is also a potential route of transmission, particularly for high-risk animals such as reptiles, chicks and ducklings, although other animals may also transmit the bacterium to humans.

Resistance to antibiotics used to treat salmonellosis in humans and animals, including fluoroquinolones and third generation cephalosporins, is occurring in many parts of the world.