Incidence and Predictors of Viral Suppression in a Cohort of Perinatally HIV Infected Children and Adolescents

Background: Outcomes beyond frequency of reaching undetectable HIV viremia are needed to guide therapeutic decisions, identify disparities and provide benchmarks to compare HIV practices. To this end we calculate the incidence rate (IR) of viral suppression (VS) and determine predictors of VS for a population of perinatally HIV infected individuals.

Methods: We include patients attending the UTHealth pediatric HIV clinic who were previously ART naïve and subsequently started on cART, maintained on the same cART regimen for at least 6 months and followed for ≥ 1 year from the start of cART. Successful VS is defined as maintenance of HIV RNA < 400 copies/ml for 1 year after initial VS was achieved. The IRVS is calculated as the number of individuals who reach VS divided by the number of patient months. Patient months is computed as the time from the initiation of cART until the date of VS, loss of follow up or switch to a 2^ndcART regimen and is expressed per 100 patient months. A Cox regression model is used to determine predictors of VS.

Results:30 HIV+ individuals are included. The population is mainly male 17 (56.6%) and black 23 (76.7%). The median age at cART initiation was 5.1 (IQR, 2.7-27.3) months; at that time 21 (70%) and 20 (66.7%) had a CD4% >25 and HIV RNA ≥ 5.0 log₁₀ copies/ml. Of the 30, 19 (63.3%) reached VS after a median of 3.7 months on cART. The overall IRVS is 7.9 per 100 person months (4.5-12.3). When the IRVS is stratified by sociodemographic; the highest IRVS are found among individuals living inside the Houston beltway 16.3 (6.1-43.5), Hispanics 12.2 (4.6-32.6), individuals on PI based regimens 10.6 (6.7-16.8) and among individuals born after 1999 11.2 (4.6-32.6). Initiation of cART within the 1^styear of life is associated with a 22% increased probability of VS while the risk of not reaching VS increases 96% when an individual missed ≥1 scheduled clinical appointment (p=0.013) and 16% for each month of delay in bringing a patient into clinical care (p=0.048). Conclusion: Our data demonstrate the importance of linking and retaining perinatally HIV infected patients in care for successful VS as well as the impact of disparities for successful VS among vulnerable populations. IRVS is suggested as a metric for comparing interventions within and across HIV practices.