Association of human papillomavirus, Neisseria gonorrhoeae and Chlamydia trachomatis co-infections on the risk of high-grade squamous intraepithelial cervical lesion.

The link between high-risk human Papillomavirus (HR-HPV) and other sexually transmitted diseases (STDs) in the risk of developing cervical cancer still unclear. Thus, in this report we investigated the rates of co-infections between HPV and other important non-HPV STDs in different cervical findings using a multiplex polymerase chain reaction (M-PCR) to simultaneously detect Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, HSV-1 and -2, and Treponema pallidum. A total of 838 women aged 18 to 68 years were screened using Papanicolaou smears for cervical abnormalities, HPV and non-HPV STDs using PCR and M-PCR methods. A total of 614 (73.3%) of the women had normal cytology (NILM) and 224 (26.7%) women exhibited abnormal cytology (≥ ASC-US). HPV-DNA prevalence was 33.9%, and HPV-16 was the most prevalent genotype in women with NILM and ≥ ASC-US cytology. Non-HPV STDs were detected in 30.4% women and T. vaginalis was the most prevalent one (11.6%). A higher increased risk of ≥ ASC-US and HSIL occurred in co-infections of HR-HPV with C. trachomatis and N. gonorrhoeae. Co-infections of HPV-DNA and HR-HPV with HSV-2 exhibited a similar increased risk but only with ≥ ASC-US. Co-infections of HPV-DNA and HR-HPV with T. vaginalis demonstrated a similar increased risk of ≥ ASC-US and HSIL. We found that C. trachomatis and N. gonorrhoeae were the primary pathogens associated with HR-HPV for the increased risk for all grades of cervical abnormalities but mainly for HSIL, suggesting a possible synergistic action in cervical lesions progression. Our results reinforce the hypothesis that some non-HPV STDs might play a role as co-factors in HPV-mediated cervical carcinogenesis. These data improve our understanding of the etiology of SCC and may also be useful for disease prevention.