HPV prevalence around the time of sexual debut in adolescent girls in Tanzania.

OBJECTIVES: Cervical cancer is the leading cause of cancer-related mortality among women in sub-Saharan Africa (SSA). Data on human papillomavirus (HPV) epidemiology in adolescent girls in SSA are essential to inform HPV vaccine policy recommendations for cervical cancer prevention. We assessed the burden of HPV infection, and risk factors for infection, among adolescent girls around the time of sexual debut. METHODS: Cross-sectional study of secondary school girls aged 17-18 years in Tanzania. Consenting participants provided samples for HPV and STI testing. Vaginal swabs were tested for 37 HPV genotypes by Roche Linear Array. Logistic regression was used to identify factors associated with HPV infection. Y chromosome was tested as a marker of recent condomless sex. RESULTS: 163/385 girls (42.3%) reported previous penetrative sex. HPV was detected in 125/385 (32.5%) girls, including 84/163 (51.5%) girls reporting previous sex and 41/222 (18.5%) reporting no previous sex. High-risk (HR) genotypes were detected in 70/125 (56.0%) girls with HPV infection. The most common HR genotype was HPV-16 (15/385; 3.9%). The prevalence of other HR HPV vaccine genotypes was between 0.8% and 3.1%. Among 186 girls who reported no previous sex, were negative for Y chromosome, and had no STI, 32 (17%) had detectable HPV. Lactobacillus sp and bacterial vaginosis-associated bacteria were negatively and positively associated, respectively, with HPV. CONCLUSIONS: HPV prevalence among adolescent girls around the time of sexual debut was high. However, prevalence of most vaccine genotypes was low, indicating that extending the age range of HPV vaccination in this region may be cost-effective.

Results from a cross-sectional sexual and reproductive health study among school girls in Tanzania: high prevalence of bacterial vaginosis.

OBJECTIVES: Bacterial vaginosis (BV) increases women's susceptibility to sexually transmitted infections (STIs) and HIV and may partly explain the high incidence of STI/HIV among girls and young women in East and southern Africa. The objectives of this study were to investigate the association between BV and sexual debut, to investigate other potential risk factors of BV and to estimate associations between BV and STIs. METHODS: Secondary school girls in Mwanza, aged 17 and 18 years, were invited to join a cross-sectional study. Consenting participants were interviewed and samples were obtained for STI and BV testing. Factors associated with prevalent BV were analysed using multivariable logistic regression. Y-chromosome was tested as a biomarker for unprotected penile-vaginal sex. RESULTS: Of the 386 girls who were enrolled, 163 (42%) reported having ever had penile-vaginal sex. Ninety-five (25%) girls had BV. The prevalence of BV was 33% and 19% among girls who reported or did not report having ever had penile-vaginal sex, respectively. BV was weakly associated with having ever had one sex partner (adjusted odds ratio (aOR) 1.59;95% CI 0.93 to 2.71) and strongly associated with two or more partners (aOR = 3.67; 95% CI 1.75 to 7.72), receptive oral sex (aOR 6.38; 95% CI 1.22 to 33.4) and having prevalent human papillomavirus infection (aOR = 1.73; 95% CI 1.02 to 2.95). Of the 223 girls who reported no penile-vaginal sex, 12 (5%) tested positive for an STI and 7 (3%) tested positive for Y-chromosome. Reclassifying these positive participants as having ever had sex did not change the key results. CONCLUSIONS: Tanzanian girls attending school had a high prevalence of BV. Increasing number of sex partner was associated with BV; however, 19% of girls who reported no penile-vaginal sex had BV. This suggests that penile-vaginal sexual exposure may not be a prerequisite for BV. There was evidence of under-reporting of sexual debut.