Cumulative plasma HIV burden disparities among adults in HIV care: implications for HIV transmission in the era of treatment as prevention

Objective:To characterize disparities in cumulative plasma HIV burden in a sample of adults accessing HIV care in San Francisco, California.Design:Observational cohort and supplemental HIV surveillance data.Methods:Data from the San Francisco Medical Monitoring Project 2012-2014 cycles and HIV surveillance data were used to create an analytic cohort followed for 2 years. Matched HIV viral load test results from HIV surveillance were used to create five viral outcome measures: any unsuppressed viral load (>200copies/ml), any transmittable viral load (>1500copies/ml), person-time spent unsuppressed, person-time spent transmittable, and 2-year viremia copy-years, a measure of cumulative plasma HIV burden. Rao-Scott chi-squares and analysis of variance examined differences in durable suppression and mean percentage time spent unsuppressed and transmittable. Weighted linear regression was used to describe differences in cumulative HIV burden.Results:Adults receiving HIV care spent approximately 12% of the 2-year time period with an unsuppressed viral load and approximately 7% of the time at a transmittable viral level. Factors independently associated with higher cumulative HIV viremia in an adjusted model included trans women identity, younger age, lower CD4(+) cell count, and a history of homelessness, incarceration, not taking ART, and nonadherence to ART.Conclusion:Although 95% of the cohort of adults in HIV care in San Francisco self-reported ART use during MMP interview, they spent on average almost 1 month per year at a transmittable viral level. We identified characteristics of those who were more likely to have higher viral burden, highlighting priorities for resource allocation to reduce onward HIV transmission.