ABSTRACT
Background: About 99.7% of cervical dysplasia and cancer cases are caused by persistent genital high-risk human papillomavirus (hrHPV) infection. Most HPV infections are subclinical and self-limiting but may persists in about 5 to 10% of infected women, resulting in pre-cancerous lesions that can progress to invasive cancer years later. This study is aimed at detecting hrHPV among apparently healthy women of reproductive age in Kaduna State, thus providing more information for effective control of HPV and cervical cancer in Nigeria. Methodology: Cervical smears were taken from 515 randomly selected apparently healthy women across selected secondary and tertiary facilities from 3 Local Government Areas (LGAs) in each Senatorial Zone of Kaduna State, Nigeria. Liquid-based cytology (LBC) technique was used to collect cervical smears and prepare smears for cytology study, while the remaining samples were stored at -80oC for molecular studies. HPV DNA were extracted from the samples and amplified by convectional PCR using specific hrHPV (HPV 16,18,31 and 45) primer sets and a broad spectrum MY09/11 and GP5+/6+ primers for a wider range of HPV genotypes. Data were analysed using the Statistical Package for Social Sciences (SPSS) version 23.0 and relationship between prevalence of hrHPV and socio-demographic factors such as age and marital status were determined using Chisquare or Fisher Exact test with p<0.05 considered statistically significant. Results: The prevalence of total HPV and hrHPV infections in the study population was 11.8% (61/515) and 9.3% (48/515) respectively. A total of 100 HPV genotypes were detected by PCR in the 61 positive smears, with 66 hrHPV types from 48 women, and 34 other HPV types from 13 women. The frequency of hrHPV genotypes detected was HPV 31 (5.8%, n=30), HPV 45 (4.1%, n=21), HPV 16 (1.7%, n=9), and HPV 18 (1.2%, n=6), with other HPV genotypes (6.6%, n=34). The frequency of cervical dysplasia was 6.4% (33/515), which was significantly associated with all HPV genotypes except HPV 16. Single HPV infection was seen in 31 (51.8%) women while multiple infections were seen in 30 (49.2%), with double infection in 21 (34.4%) and triple infections in 9 (14.7%). Conclusion: The prevalence of hrHPV infection was high among women in Kaduna State, Nigeria. DNA-based screening for hrHPV genotypes and production of new vaccine that will protect against the predominant hrHPV genotypes are thus recommended for the prevention of cervical cancer in Nigeria, Africa and beyond.