Salmonella infection is usually caused by eating raw or undercooked meat, poultry, and eggs or egg products or by drinking unpasteurized milk. The incubation period — the time between exposure and illness — can be 6 hours to 6 days. Often, people who have salmonella infection think they have the stomach flu. Possible signs and symptoms of salmonella infection include: 
Diarrhea
Stomach (abdominal) cramps
Fever
Nausea
Vomiting
Chills
Headache
Blood in the stool
 Signs and symptoms of salmonella infection generally last a few days to a week. Diarrhea may last up to 10 days, but it may take several months before bowels return to usual stool habits. A few varieties of salmonella bacteria result in typhoid fever, a sometimes deadly disease that is more common in developing countries.