Association between high risk human papillomavirus infection and co-infection with Candida spp. and Trichomonas vaginalis in women with cervical premalignant and malignant lesions

Background: Human papillomavirus (HPV) is the necessary cause of cervical cancer. Cervico-vaginal infection with pathogens like Chlamydia is a likely cofactor. The interactions between HPV, Trichomonas vaginalis (TV) and Candida spp. are less understood, though inflammation induced by these pathogens has been demonstrated to facilitate oncogenesis.

Objective: Our study aimed to evaluate the association between Candida spp. and TV co-infection with HPV in cervical oncogenesis.

Study design: Women with normal cervix who were high-risk HPV-negative (N=104) and HPV-positive (N=105); women with CIN 1 (N=106) and CIN 2/CIN 3 (N=62) were recruited from a community based cervical cancer screening program. Cervical cancer patients (N=106) were recruited from a tertiary care oncology clinic. High-risk HPV was detected by Hybrid Capture II technique; Candida spp. and TV were detected by culturing the high vaginal swabs followed by microscopic examination in all. The disease status was established by histopathology in all the women.

Result: HPV-positive women had significantly higher risk of having precursor lesions (of any grade) and cancer compared to HPV-negative women. Candida spp. or TV infection did not alter the risk of low grade or high grade lesions among HPV- positive women. HPV positive women co-infected with TV had higher risk of cervical cancer but not those co-infected with Candida spp.

Conclusion: The higher risk of cancer observed in the women co-infected with HPV and TV without any enhanced risk of CIN 3 suggests secondary infection of the malignant growth by TV rather than any causal role. Co-infection with Candida spp. and/or TV infection did not increase the carcinogenic effect of HPV on cervix.