High prevalence and co-infection of high-risk Human Papillomavirus genotypes among unvaccinated young women from Paraguay.

Paraguay launched a human papillomavirus (HPV) vaccination program in 2013, so virological surveillance is important for measuring the impact of HPV vaccines. This study aimed to estimate the type-specific HPV frequency in unvaccinated sexually active women aged 18-25 years in the metropolitan area of Asuncion as a baseline for monitoring the HPV vaccination program. This study included 208 women, attending the Central Laboratory of Public Health between May 2020 and December 2021, were invited for testing through social networks and flyers at local health centers and higher education institutes. All participants who agreed to contribute to the study signed a free, prior, and informed consent form and answered a questionnaire that included basic demographic data and determining factors of HPV infection. Human papillomavirus detection and genotyping were conducted using the CLART HPV2 test (Genomica, Madrid, Spain) that allows the individual identification of 35 genotypes. 54.8% women were positive for any HPV type, with 42.3% positive for high-risk HPV (HR-HPV) types. Several factors were associated with HPV detection including the number of sexual partners, new sexual partners, non-use of condoms, and history of other sexual infections. Moreover, multiple infections were identified in 43.0% of the young women. We detected 29 different viral types present in both single and multiple infections. HPV-58 was the most commonly detected HPV type (14.9%), followed by HPV-16, HPV-51, and HPV-66 (12.3%). We estimated the prevalence of bivalent (16/18), quadrivalent (6/11/16/18), and nonavalent (6/11/16/18/31/33/45/52/58) vaccine types to be 8.2%, 13%, and 38%, respectively. These results reinforce the importance of surveillance studies and provide the first data regarding circulating HPV genotypes in the unvaccinated population in Paraguay, thus generating a baseline to compare future changes in the overall and type-specific HPV prevalence after HPV vaccination.