Time above 1500 copies

Abstract

Objective We examined HIV transmission potential of patients in care by analyzing the amount of person-time spent above a viral load threshold that increases risk for transmission. Design Observational cohort and supplemental data. Methods The cohort included HIV patients who received care at six HIV clinics in the United States, from 1 April 2009 to 31 March 2013, and had two or more viral load tests during this interval. Person-time (in days) above a viral load of 1500 copies/ml out of the total observation time was determined by inspecting consecutive pairs of viral load results and the time intervals between those pairs. The person-time rate ratios comparing demographic and clinical subgroups were estimated with Poisson regression. Results The cohort included 14 532 patients observed for a median of 1073 days with a median of nine viral load records. Ninety percent of the patients had been prescribed antiretroviral therapy. On average, viral load exceeded 1500 copies/ml during 23% of the patients’ observation time (average of 84 days per year, per patient). Percentage of person-time above the threshold was higher among patients who had more than a fourth of their viral load pairs exceeding a 6-month interval (34% of observation time), patients not on antiretroviral therapy (58% of time), new/re-engaging patients (34% of time), patients 16–39 years of age (32% of time), and patients of black race (26% of time). Conclusion HIV patients in care spent an average of nearly a quarter of their time with viral loads above 1500 copies/ml, higher among some subgroups, placing them at risk for potentially transmitting HIV to others.

Time Spent with HIV Viral Load > 1500 Copies/mL Among Persons Engaged in Continuity HIV Care in an Urban Clinic in the United States, 2010–2015

“…The proportion of person-time in care that was spent with HIV RNA >1500 copies/mL (15%) in our study was less than that found in a prior study to which our cohort contributed data (23%) (26) and to a study in the HIV Outpatient Study (24%) (27). This may be explained by differences in the study populations, but also by the fact that our sample was in care during a slightly more recent time period (2010–2015 versus 2009–2012 and 2000–2014, respectively) while norms about ART initiation were changing rapidly.…”

Durable Viral Suppression and Transmission Risk Potential Among Persons With Diagnosed HIV Infection: United States, 2012–2013

“…Those who did not sustain durable viral suppression also spent an average of 60% of the 2-year time with VL above 200 copies/mL as well as a considerable length of time above 1,500 and 10,000 copies/mL, posing risk for further transmission. 5,15 The dynamic VL trajectories are easily overlooked with the cross-sectional assessment of last VL measure, which revealed 82.9% suppression in the analytic cohort. Clearly, these longitudinal measures of VL dynamics provide more granular data with implications for HIV treatment and prevention.…”

“…Using the method developed by Marks et al, 15 we estimated the amount of time (in days) spent above 1,500 copies/mL for each pair of VL results, summed the estimated days above the 1,500 cut-point during consecutive pairs of VL results to yield a single value per person, and then aggregated the amount of person-time above the cut-point across the analytic cohort over the 2-year period. Given evidence suggesting a dose-response relationship between increasing plasma viremia and sexual transmission in serodiscordant couples, 5 we also used a higher plasma level (10,000 copies/mL) to examine HIV transmission risk potential.…”

“…4,13,14 Several studies have begun to evaluate longitudinal VL measures. 4,13–15 Data from six HIV clinics showed that using a single VL measure to estimate the percentage of HIV patients with durable viral suppression (all VLs < 200 copies m/L) overestimated by 16% (relative difference) over a 12-month period. 13 Longitudinal VL measures capture an individual’s cumulative exposure to viral replication over time, serving as a putative proxy biomarker of inflammation and immune system activation.…”

“…4 Using data from six clinics, one study examined the amount of person-time spent above 1,500 copies/mL, a VL level at which HIV transmission risk begins to increase. 15 While these findings are informative, clinical cohorts inherently have a degree of selection bias. In comparison, VL data available from the national HIV surveillance system provides a means for conducting population-level assessments of longitudinal plasma HIV burden and transmission risk potential.…”