Salmonellosis is a foodborne illness caused by Salmonella bacteria that affects the gastrointestinal tract. Common symptoms include diarrhea, fever, vomiting, and abdominal cramps. It can spread through contaminated foods like poultry, eggs, meat and dairy. Young children, the elderly, and those with weak immune systems are most at risk. Prevention methods include proper handwashing and cooking foods thoroughly to kill any Salmonella bacteria.