Salmonellosis is a symptomatic infection caused by bacteria of the Salmonella type. It is also a food-borne disease and are defined as diseases, usually either infectious or toxic in nature, caused by agents that enter the body through the ingestion of food. In humans, the most common symptoms are diarrhea, fever, abdominal cramps, and vomiting. Symptoms typically occur between 12 hours and 36 hours after exposure, and last from two to seven days. Occasionally more significant disease can result in dehydration. The old, young, and others with a weakened immune system are more likely to develop severe disease. Specific types of Salmonella can result in typhoid fever or paratyphoid fever.

There are two species of Salmonella: Salmonella bongori and Salmonella enterica with many subspecies. However, subgroups and serovars within a species may be substantially different in their ability to cause disease. This suggests that epidemiologic classification of organisms at the subspecies level may improve management of Salmonella and similar pathogens.

Both vegetarian and non-vegetarian populations are susceptible to Salmonella infections due to the consumption of contaminated meat and milk. Infection is usually spread by eating contaminated meat, eggs, water or milk. Other foods may spread the disease if they have come into contact with manure. A number of pets including cats, dogs, and reptiles can also carry and spread the infection. Diagnosis is by a stool test or blood tests.

Efforts to prevent the disease include the proper washing, preparation, and cooking of food to appropriate temperature. Mild disease typically does not require specific treatment. More significant cases may require treatment of electrolyte problems and intravenous fluid replacement. In those at high risk or in whom the disease has spread outside the intestines, antibiotics are recommended.

Salmonellosis is one of the most common causes of diarrhea globally. In 2015, 90,300 deaths occurred from nontyphoidal salmonellosis, and 178,000 deaths from typhoidal salmonellosis. In the United States, about 1.35 million cases and 450 deaths occur from non-typhoidal salmonellosis a year. In Europe, it is the second most common foodborne disease after campylobacteriosis.