Which organism can cause diarrhea in patients who consume raw seafood, particularly oysters?

The organism that can cause diarrhea in patients who consume raw seafood, particularly oysters, is Vibrio. This genus includes several species, with Vibrio parahaemolyticus and Vibrio vulnificus being notable for their association with gastrointestinal illness stemming from the consumption of undercooked or raw seafood.

In particular, Vibrio parahaemolyticus is a common cause of gastroenteritis, leading to watery diarrhea, which can occur shortly after the consumption of contaminated oysters. Vibrio vulnificus is known to cause more severe illness, especially in individuals with underlying liver disease, and can lead to both gastrointestinal disease and more serious infections, especially when raw oysters are consumed.

The light cooking of oysters or consumption of raw oysters can introduce these bacteria into the gastrointestinal tract, where they can then proliferate and lead to symptoms such as diarrhea, abdominal cramps, and nausea. Recognizing the risk associated with raw seafood is essential for preventing these types of infections.