Pulmonary trichomoniasis: improved diagnosis by using polymerase chain reaction targeting trichomonas tenax 18Sr -RNA gene in sputum specimens

ABSTRACT

This study included 250 individuals [100 immunocompromised patients with chest complaints [group I], 100 patients with chronic pulmonary diseases [group II] and 50 healthy individuals as controls [group III]]. Twenty cases were positive in one or more methods giving for pulmonary trichomoniasis [a total prevalence of 8%; 12% in group I and 8% in group II and none in group III], with no significant difference between groups I and II. Pulmonary trichomoniasis was prevalent at an age ranged between 31-50 years and in males [10%] than females [5.5%] with no significant difference. Among the 200 examined patients, pulmonary trichomoniasis had a prevalence of 3% by wet mount. 2.5% by Giemsa-stained smear, 7% by culture compared with 10% by polymerase chain reaction [PCR]. Culture was used as a reference standard. All culture positive specimens were PCR positive, showing a product at 0.8 Kb long by agarose gel electrophoresis and 100% sensitivity. Wet mount, Giemsa-stained smear and culture had a sensitivity of 43%, 35.7% and 70%, respectively. No PCR negative specimens were positive by any of the other methods. Six specimens were culture negative PCR positive and remained PCR positive when retested three times. The calculated specificity of PCR was 97%. No PCR target product was amplified with DNAs of T. vaginalis and various pulmonary pathogens. The results were discussed