Role of polymerase chain reaction in the diagnosis of Trichomonas vaginalis infection in human immunodeficiency virus-infected individuals from India (South).

Background: Trichomonas vaginalis is a protozoan parasite and an etiological agent for trichomoniasis, a sexually transmitted infection (STI). Fifty to eighty percentage of women with trichomoniasis are asymptomatic and in the absence of treatment the infection persists longer.

Aim: To evaluate the role of polymerase chain reaction (PCR) in the diagnosis of trichomoniasis and also to look at the frequency of infection among human immunodeficiency virus (HIV) infected women.

Methods: A non-nested PCR was standardized to detect 102 bp size amplified product of the adhesin gene of T. vaginalis. The real time performance of this assay was performed with vaginal swab samples from 198 HIV-seropositive women who attended the infectious disease clinic and compared with wet mount and culture in Diamond's modified media.

Results: Among the prospectively studied 198 HIV-infected women, 1 (0.51%) was positive by wet mount, 6 (3.03%) were positive by culture and 10 (5.02%) were positive by the PCR. There was a significant observed agreement between the PCR and culture (k=0.74, Z=10.7, P<0.0000).

Conclusion: Our study showed that the PCR assay for the amplification of adhesion gene is a highly sensitive method to screen the high risk group individuals like HIV-positive women for Trichomonas vaginalis compared to the culture. Testing algorithm should be, wet mount and if negative, test by PCR as it is rapid compared to culture which takes 7 days.