Compare non-typhoidal Salmonella and Salmonella Typhi in terms of clinical presentation and disease course.

• A. Non-typhoidal Salmonella causes self-limited gastroenteritis with fever and diarrhea; Typhi causes typhoid fever with prolonged fever, bacteremia, abdominal symptoms, and rose spots.
• B. Non-typhoidal Salmonella causes typhoid; Typhi causes self-limited gastroenteritis.
• C. Both cause identical disease.
• D. Typhi only causes diarrhea.

Answer: (A)

The key idea is that these Salmonella infections show very different clinical pictures. Non-typhoidal Salmonella typically causes a localized, self-limited gastroenteritis: abrupt onset of fever with gastroenteric symptoms like abdominal cramps and diarrhea (often non-bloody, sometimes with vomiting). The illness usually resolves on its own within a few days, and systemic illness is uncommon in healthy individuals, though dehydration can occur and vulnerable people may have more severe disease.

In contrast, Salmonella Typhi produces typhoid fever, a systemic illness. It features prolonged or stepwise fever, malaise, abdominal pain, and often hepatosplenomegaly, with bacteremia. Classic clues can include constipation early on and distinctive rose spots on the trunk. The illness tends to be longer and more serious, and complications such as intestinal perforation or hemorrhage can occur. There is also a potential carrier state after recovery, particularly in the gallbladder.

So the statement that non-typhoidal Salmonella causes self-limited gastroenteritis with fever and diarrhea, while Typhi causes typhoid fever with prolonged fever, bacteremia, abdominal symptoms, and rose spots, best captures the distinct clinical presentations and disease courses of the two.