Multiple Human Papillomavirus infection and high grade cervical intraepithelial neoplasia among women with cytological diagnosis of atypical squamous cells of undetermined significance or low grade squamous intraepithelial lesions.

Objective. To evaluate the effect of multiple human papillomavirus (HPV) infection on the prevalence of cervical intraepithelial neoplasia (CIN) among women undergoing colposcopy following a cytological diagnosis of atypical squamous cells of undetermined significance (ASCUS) or low grade squamous intraepithelial lesions (LSIL). Methods. HPV type-specific sequences of 15 high-risk and 10 low risk types were detected by the line probe, INNO-LiPA HPV genotyping assay before colposcopic examination and targeted biopsies. Multinomial logistic regression was used to evaluate the effect of multiple infection on pathologic outcome adjusting for confounders. Results. The prevalence of HPV infection in the 1218 women enrolled was 69.9% (851/1218). HPV 16 (37.4%), 31 (26.1%), 51 (17.4%), 52 (15.7%) and 18 (14%) were the commonest viral types identified. Overall, the rates of multiple infection were 22.5% (153/680) among subjects with negative colposcopy/biopsy, 63.6% (218/343) and 79.5% (155/195) among those with CIN 1 and CIN≥2, respectively (p for trend b.001). The corresponding rates among subjects uninfected by HPV 16 or 18 were 13.5% (77/572), 57.4% (112/195) and 62% (48/77), respectively (p for trend b.001). In multinomial logistic regression, the odds ratio of CIN≥2 in multiple high risk as compared to single high risk HPV infection was 4.33 (95% confidence intervals=2.32–7.14) in the overall population and 2.76 (95% confidence intervals=1.36–5.59) among women uninfected by HPV 16 or 18. Conclusions. Multiple HPV infection is a significant risk factor for CIN≥2 among women undergoing colposcopy because of ASCUS/LSIL.