Which STD is characterized by a fishy odor in vaginal discharge?

The condition characterized by a fishy odor in vaginal discharge is bacterial vaginosis. This condition occurs due to an imbalance of the normal bacteria found in the vagina, leading to an overgrowth of certain types of bacteria. One of the hallmark symptoms of bacterial vaginosis is a thin, grayish-white discharge that often has a strong fishy smell, which may become more noticeable after sexual intercourse or during menstruation.

Chlamydia, on the other hand, typically does not result in a fishy odor and may often present asymptomatically. Trichomoniasis can sometimes have a foul-smelling discharge, but it is more often associated with a frothy, yellow-green discharge rather than the specific fishy odor seen in bacterial vaginosis. HIV generally does not cause changes in vaginal discharge that would present as a fishy odor.

Thus, the distinctive fishy odor of vaginal discharge is a key indicator that points to bacterial vaginosis as the correct condition.