A Challenging Knowledge Gap: Estimating Modes of HIV Acquisition Among Adolescents Entering HIV Care During Adolescence

Characterizing HIV acquisition modes among adolescents with HIV (AHIV) enrolling in care during adolescence is a challenging gap that impacts differential interventions. We explored whether primary data collection with targeted questionnaires may address this gap and improve understanding of risk factors and perceptions about adolescents’ HIV acquisition, in Kenyan AHIV entering care at ≥10 years, and their mothers with HIV (MHIV). Clinical data were derived through chart review. Among 1073 AHIV in care, only 26 (2%) met eligibility criteria of being ≥10 years at care enrollment, disclosed to, and with living MHIV. Among 18/26 AHIV-MHIV dyads enrolled (median age of AHIV 14 years), none had documented HIV acquisition modes. Data suggested perinatal infection in 17/18 AHIV, with 1 reported non-perinatal acquisition risk factor, and some discordance between adolescent-mother perceptions of HIV acquisition. In this difficult-to-enroll, vulnerable population of AHIV-MHIV dyads, primary data collection can enhance understanding of AHIV acquisition modes. This cross-sectional study was conducted at Moi Teaching and Referral Hospital (MTRH), the largest public healthcare facility in western Kenya and headquarters of the Academic Model Providing Access to Healthcare (AMPATH).29,30 MTRH HIV clinics care for children and adults based on the Kenyan national guidelines and have a dedicated AHIV clinic, where participants were enrolled. 31 Patients are managed with an electronic medical record system including linkages between MHIV and their children. 32 This study was approved by the MTRH/Moi University College of Health Sciences Institutional Research and Ethics Committee and Indiana University IRB. Participants ≥18 years provided written informed consent. AHIV <18 years provided written assent with parental consent. Medical records were used to identify eligible AHIV and their MHIV enrolled at MTRH. First, we identified all AHIV 10 to 19 years active in care, defined as attending an appointment within 3 months of study start (February 1, 2019), or if censored, within 3 months of a scheduled appointment. Next, we excluded AHIV <10 years of age at enrollment in HIV care. This cutoff was selected because UNAIDS defines adolescence as 10 to 19 years and because HIV infection among children <10 years is equally distributed between boys and girls and largely restricted to those with MHIV, making perinatal transmission most likely.16,33 We excluded adolescents with deceased mothers, those whose mothers did not have HIV (precluding perinatal transmission), those with unknown maternal HIV and vital statuses, and those who transferred to AMPATH after receiving care at non-AMPATH sites at <10 years of age. Finally, we did not recruit dyads in which the adolescent’s HIV status was not disclosed to both adolescent and mother, to avoid risk of disclosure through participation. We aimed to sample the first 20 eligible AHIV-MHIV dyads. Chart reviews derived documented modes of HIV acquisition, dates of enrollment in care and ART initiation, World Health Organization (WHO) stage and CD4 at ART initiation, and prior ART regimens and HIV viral loads. Date of enrollment into HIV care was considered the HIV diagnosis date unless the latter was known precisely, as diagnosis dates are not routinely available. Adolescent height-for-age z-scores at study enrollment were calculated using WHO growth reference charts. 34 Questionnaires were administered privately to each participant between February 2019 and January 2020. AHIV were asked about how they believed they acquired HIV and exposures associated with HIV acquisition prior to diagnosis, including sexual intercourse, any sexual contact with an individual living with HIV, circumcision, sexually transmitted infections, blood transfusions or surgery, injection drug use, and use of other substances including alcohol, tobacco, marijuana, heroin, and inhalants. MHIV were asked about their breastfeeding practices and utilization of prevention of mother-to-child transmission (PMTCT) services, presence of other children living with HIV, and perceptions about how their adolescents acquired HIV. Whole blood samples were collected from all participants. Viral load testing was performed at the AMPATH research laboratory using the M2000 Realtime System from Abbott laboratories (Abbott park, Illinois, Chicago USA). Frozen plasma samples were batched and shipped at −80°C to the Kantor Laboratory at the Providence-Boston Center for AIDS Research. Three samples from AHIV with 3 viremia levels (ie, <1000, 1000-10 000, and >10 000 copies/mL) were selected for genotyping. The chart and questionnaire data were summarized using frequencies and medians with interquartile ranges (IQR). Viral suppression at study enrollment was defined using a threshold of <1000 copies/mL based on Kenya and WHO HIV treatment guidelines. 35 Drug resistance interpretation and predicted susceptibilities were evaluated using Stanford Database tools. 36 These data were graphed in the context of each subjects’ ART regimens, viral loads, and CD4 counts since the date they enrolled in care.