Pulmonary trichomoniasis and Trichomonas tenax.

Pulmonary trichomoniasis is usually caused by aspirated Trichomonas tenax. Adult men with chronic purulent or necrotic pulmonary disease are usually affected. Sixty-eight patients were previously described. A Russian study demonstrated pulmonary trichomoniasis in 19 of 112 patients (17%), mostly in patients with lung cancer, lung abscess, or bronchiectasis. Rarely, pulmonary trichomoniasis may be caused by an intra-abdominal (T. hominis) or genitourinary (T. vaginalis) infection. T. tenax is usually regarded as a harmless commensal of the human mouth. Its prevalence ranges from 4% to 53% and may exceed that of vaginal infection with T. vaginalis in adult females. It is frequently found in patients with poor oral hygiene. Cultural identification is superior to microscopic examination of wet-smear, gram-stained and Papanicolaou-stained preparations. Aspirated pulmonary trichomoniasis is an opportunistic infection. Until the question of possible pathogenicity is resolved, metronidazole should be given. The underlying pulmonary disease should be vigorously treated.