[A first case report of empyema caused by Tetratrichomonas species in Japan]

Trichomonad is a type of flagellate that parasitizes the human oral cavity, intestine, or vagina. However, respiratory infection is rare. We report a patient with pyothorax related to Tetratrichomonas species, which is the first reported case in Japan. The patient was a 66-year-old female. She consulted the Emergency Outpatient Unit of our hospital with fever, dyspnea, and the retention of pleural effusion. The appearance of the pleural effusion collected by thoracic drainage was brown, fetid pus. On microscopy, Trichomonad was detected in the pleural effusion. On a gene test, Tetratrichomonas sp. was identified. Based on this experience, we propose that non-stained specimens should be examined to detect Trichomonad on a puncture fluid test. (Case report).