Salmonella is a bacterial disease that infects the intestinal tract and causes illnesses like typhoid fever and food poisoning. People usually become infected by eating contaminated food like meat, poultry, or eggs or drinking contaminated water. The main symptoms are diarrhea, fever, and abdominal cramps within 12-72 hours, and the illness typically lasts 4-7 days. The disease is caused by salmonella bacteria rather than a virus.