Explosive watery diarrhea with severe abdominal pain after eating raw shellfish is most characteristic of infection caused by which organism?

• A. Campylobacter jejuni
• B. Helicobacter pylori
• C. Shigella dysenteriae
• D. Vibrio parahaemolyticus

Answer: (D)

Exposure to raw shellfish points to a marine Vibrio infection. Vibrio parahaemolyticus, a salt-loving bacterium found in seawater, is a classic cause of acute gastroenteritis after eating raw or undercooked seafood. The typical picture is sudden, profuse, watery diarrhea with severe abdominal cramps and sometimes nausea or vomiting, usually starting soon after ingestion. This explosive watery diarrhea linked to seafood fits this organism best.

In contrast, Campylobacter jejuni is commonly linked to poultry or unpasteurized dairy and often causes inflammatory or sometimes bloody diarrhea with fever; Helicobacter pylori causes chronic gastritis and ulcers rather than acute diarrhea after seafood; Shigella dysenteriae causes dysentery with blood and mucus and is more associated with fecal-oral spread in crowded or unsanitary settings. So the presented scenario is most characteristic of Vibrio parahaemolyticus infection.