Diagnosis of symptomatic and asymptomatic trichomonas vaginalis infection by applying one tube nested pcr to vaginal discharge

ABSTRACT

One tube nested PCR targeting a species-specific Tv-E650 repeat family of T. vaginalis genome was applied to vaginal discharge specimen to diagnose symptomatic and asymptomatic trichomoniasis. The test was compared with axenic culture examination, wet mount preparation and Papanicolaou stained smears. A total of 450 cases, symptomatic and symptomatic, was collected over 2 years. Out of 290 symptomatic women with cervicovaginitis and 160 asymptomatic women, 35 were culture positive for trichomoniasis. All culture positive specimens were PCR- positive, giving a single product at 290 bp by agarose gel electrophoresis and recording 100% sensitivity similar to culture examination. Among the 35 culture positive specimens, 12 were positive by wet mount and 21 were positive by Pap smear, giving a 34.2% and 60% sensitivity, respectively. The standard and boiling DNA extraction methods were equally reliable, but the latter was more simple, rapid and cheap. No specimens negative by PCR for trichomoniasis were positive by culture, wet mount or Pap smear. Moreover, specimens from cases with cervicovaginitis of non- trichomonal origin were negative by PCR