Abstract
Trichomonas tenax was observed in the pleural effusion of Japanese male patient (70-year-old) with purulent pleuritis. The trichomonad protozoan was found to be concomitant infection with Escherichia coli in the purulent effusion. The protozoan measured an average size of 12.44μ in length and 8.52μ in width (n=30). Based on the morphological features, such as size of trichomonad, number of flagella and short undulating membrane, the organism was identified as T. tenax. The aetiological aspects in this case, however, still remained uncertain, though the patient might be partially affected by a great number of T. tenax in the pleural cavity. As to the two organisms found in the pleural effusion, the route of invasion was not known. The homosexual behaviour of the patient, however, might have some connection with the route of invasion.
