Prevalence, incidence and clearance of human papillomavirus infection among young primiparous pregnant women in Kampala, Uganda

The proportion of women who have already been exposed to human papillomavirus (HPV) infection by the time they first become pregnant, and the influence of pregnancy and delivery on the course of HPV infection are unclear. In Kampala, Uganda, 987 young primiparous pregnant women aged <25 years had gynaecological examination and liquid-based cytology. In the follow-up, women acted as their own controls, i.e., 1st/2nd versus 3rd trimesters (105 women), and during pregnancy versus after delivery (289 women). HPV was assessed using highly sensitive PCR assays. Prevalence of HPV and HIV infections at baseline were 60.0% and 7.3%, respectively. HPV16 and 18 were detected in 8.4% and 5.8%, respectively, i.e., less frequently than HPV51 (8.7%) and 52 (12.1%). At follow-up new HPV infections were detected in 42.9% of women between the 1st/2nd and 3rd trimesters, and 38.1% between pregnancy and delivery, but 50.4% and 71.8% of HPV infections, respectively, cleared, leaving HPV prevalence unchanged in the different periods. Prevalence of cytological abnormalities diminished after delivery (from 21.2% to 12.4%). Presence of genital warts and sexually transmitted infections other than HPV were the strongest risk factors for prevalent or incident HPV infection. Clearance was lower among HIV-positive women. In conclusion, HPV prevalence was high in primiparous women in Uganda, but pregnancy did not seem to be a period of special vulnerability to the infection. (C) 2008 Wiley-Liss, Inc.