Patterns of Detectable Viral Load in a cohort of HIV-infected adolescents on antiretroviral therapy

• Main Author: Sher, Rebecca Yael Nthabiseng
• Other Authors: Muloiwa, Rudzani
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2019
• Subjects: Paediatrics
• Online Access: http://hdl.handle.net/11427/29716

Background Despite improved treatment and access to care, adolescent AIDS deaths are decreasing more slowly than in any other age group. There is lack of longitudinal data around adolescent adherence and the dynamics of viraemia over time. We aimed to describe patterns of detectable viral load in a cohort of adolescents attending an antiretroviral clinic in Cape Town, South Africa. Methods We conducted a retrospective cohort study of all patients on ART aged 10-19 years. Participants were included if they underwent at least two HIV viral load (VL) measurements and attended the Groote Schuur Hospital HIV Clinic for at least 24 months between 2002 and 2016. The primary outcome was two consecutive VL >100 copies/ml, in line with the lower limit of detection of assays in use over the follow-up period. Results Of 482 screened subjects, 327 met inclusion criteria. Most subjects were vertically infected (n= 314; 96%), and 170 (52%) were male. Overall, 203 episodes of confirmed detectable VL involving 159 (49% [95% CI 43%–54%]) subjects were experienced during the follow-up period. A total of 111 (34%) subjects never experienced detectable VL, while 16 (5%) never suppressed throughout the follow-up period. Median age at first detectable VL was 14 (IQR 11-16) years. Of the 159 subjects who experienced detectable VL, 102 (64%) re-suppressed, of which 38 (37%) had a subsequent detectable VL. Six subjects had genotyped resistance to protease inhibitors. Four of these never suppressed, while two suppressed on salvage regimens. Total follow-up time was 1723 person years (PY), of which 880 (51%) were contributed by the 159 subjects who experienced detectable VL. Overall time with detectable VL was 370 PY. This comprised 22% of total follow-up time, but 42% of the follow-up time contributed by those who experienced detectable VL. The rate of detectable VL was 11.8 (95% CI 10.3–13.5) episodes per 100 PY. The risk increased by 24% for each year of increasing age (RR 1.24 [95% CI 1.17-1.31]; p< 0.0001). Neither prevalence, duration nor rate of detectable VL was influenced by gender. Conclusion Detectable VL was seen in nearly half of adolescents, with the rate increasing with age. Viraemia was not a static process, and adolescents moved in and out of this state as adolescence progressed. Further study is warranted to correlate these findings with risks and clinical outcomes.