Daniel Kwaro, Penelope A. Phillips-Howard, Garazi Zulaika, Anna Maria van Eijk, Linda Mason, Samuel Omondi Owino, Elizabeth Nyothach, Emily Kerubo, Duolao Wang, David Obor, Feiko O. ter Kuile, Tao Chen, Valarie Opollo, Isaac Ngere, and Boaz Oyaro
Background Adolescence is a sensitive time for girls’ sexual and reproductive health (SRH), as biological changes occur concurrently with heightening pressures for sexual activity. In western Kenya, adolescent girls are vulnerable to acquiring sexually transmitted infections (STIs), such as HIV and herpes simplex virus type 2 (HSV-2), and to becoming pregnant prior to reaching adulthood. This study examines associations between individual, household, and partner-related risk factors and the prevalence of sex, adolescent pregnancy, HIV, and HSV-2. Methods and findings We report baseline findings among 4,138 girls attending secondary school who were enrolled between 2017 and 2018 in the Cups or Cash for Girls (CCG) cluster randomized controlled trial in Siaya County, rural western Kenya. Laboratory confirmed biomarkers and survey data were utilized to assess the effects of girls’ individual, household, and partner characteristics on the main outcome measures (adolescent reported sex, prior pregnancy, HIV, and HSV-2) through generalized linear model (GLM) analysis. Complete data were available for 3,998 girls (97%) with median age 17.1 years (interquartile range [IQR] 16.3 to 18.0 years); 17.2% were HSV-2 seropositive (n = 686) and 1.7% tested positive for HIV (n = 66). Sexual activity was reported by 27.3% girls (n = 1,090), of whom 12.2% had been pregnant (n = 133). After adjustment, orphanhood (adjusted risk ratio [aRR] 2.81, 95% confidence interval [CI] 1.18 to 6.71, p-value [p] = 0.020), low body mass index (BMI) (aRR 2.07; CI: 1.00 to 4.30, p = 0.051), and age (aRR 1.34, 1.18 to 1.53, p < 0.001) were all associated with HIV infection. Girls reporting light menstrual bleeding (aRR 2.42, 1.22 to 4.79, p = 0.012) for fewer than 3 days (aRR 2.81, 1.16 to 6.82, p = 0.023) were over twice as likely to have HIV. Early menarche (aRR 2.05, 1.33 to 3.17, p = 0.001) was associated with adolescent pregnancy and HSV-2–seropositive girls reported higher rates of pregnancy (aRR 1.62, CI: 1.16 to 2.27, p = 0.005). High BMI was associated with HSV-2 (aRR 1.24, 1.05 to 1.46, p = 0.010) and sexual activity (aRR 1.14, 1.02 to 1.28, p = 0.016). High levels of harassment were detected in the cohort (41.2%); being touched indecently conveyed the strongest association related to reported sexual activity (aRR 2.52, 2.26 to 2.81, p < 0.001). Study limitations include the cross-sectional design of the study, which informs on the SRH burdens found in this population but limits causal interpretation of associations, and the self-reported exposure ascertainment, which may have led to possible underreporting of risk factors, most notably prior sexual activity. Conclusions Our findings indicate that adolescent girls attending school in Kenya face frequent harassment for sex and are at high risk of pregnancy and HSV-2, with girls experiencing early menarche particularly vulnerable. Targeted interventions, such as earlier sexual education programs, are warranted to address their vulnerability to SRH harms. Trial registration ClinicalTrials.gov NCT03051789., In a cross sectional analysis, Garazi Zulaika and colleagues study associations between risk factors and prevalence of sexual activity, pregnancy, and HIV and HSV-2 infections among adolescent girls in rural Kenya., Author summary Why was this study done? Girls in low- and middle-income countries (LMICs) face severe health risks from becoming pregnant prior to reaching adulthood and from exposure to sexually transmitted infections (STIs) such as HIV and herpes simplex virus type 2 (HSV-2). Key factors found to be linked to adolescent sexual and reproductive health (SRH) in LMICs include household wealth, age at first sex, and schooling. Evidence of a positive association between girls’ SRH, and their education and economic potential has strengthened international resolve to identify risks and improve conditions that adolescent girls face in these settings. What did the researchers do and find? We collected data from 3,998 girls attending 96 public secondary day schools in 2017 and 2018 as part of the baseline assessment of a randomized controlled study. We explored whether girls’ personal characteristics were associated with SRH harms, namely adolescent sex, early pregnancy, and acquisition of HIV and HSV-2. We found biological factors including girls experiencing early menarche, having lighter periods, and body mass index (BMI); household level factors including being unhappy at home, being orphaned, and coming from poorer households; and social factors including experiencing harassment for sex both in and out of school or being touched indecently were significantly associated with girls’ sexual and reproductive harms, such as pregnancy, HSV-2, and/or HIV. What do these findings mean? These findings illustrate that the burden of SRH harms faced by adolescent girls attending school in rural western Kenya is high. Interventions and programs to improve SRH and continued education need to address both environmental and biological risk factors among vulnerable populations.