Background
HIV viral blips defined as a viral load between 51-999 copies/mL (preceded and followed by <50 cp/mL at least 1 to 12 months apart) occur among people with HIV (PWH) despite effective antiretroviral therapy (ART). Within the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD), we aimed to describe the prevalence and risk factors associated with experiencing at least one viral blip.
Methods
US and Canadian PWH 18 years or older in the NA-ACCORD were followed from the first suppressed viral load (<50 cp/mL) measured >12 months after ART initiation or 1/1/2010 until the earliest of viral blip (event), the last visit prior to a gap of >2 years without a CD4 or viral load (loss to follow-up), death or 12/31/2020. Logistic regression models estimated crude and adjusted odds ratios (aOR) and 95% confidence intervals to identify factors associated with experiencing a viral blip (see Figure for co-variates included in models).
Results
Among 77,670 PWH, 18,327 (24%) experienced a viral blip during the study period. Older age was associated with increased odds of viral blip (per 10-year increase in age: aOR=1.05 [1.03, 1.07]). The odds of a viral blip were higher among non-Hispanic Black (aOR=1.12 [1.07, 1.17]) and Hispanic (aOR=1.14 [1.07, 1.21]) PWH compared with non-Hispanic white PWH. PWH reporting injection drug use (aOR=1.13 [1.04, 1.23]) or men who have sex with men (aOR=1.15 [1.07, 1.23]) had higher odds of viral blips than PWH reporting heterosexual HIV risks. The odds of a viral blip were higher among PWH with BMI >24.9 kg/m2: aOR=1.12 [1.07, 1.17] and lower among PWH with BMI <19 kg/m2; aOR=0.60 [0.54, 0.67] compared with PWH with a BMI between 19-24.9 kg/m2 measured at study completion. PWH with lower CD4 cell counts and higher HIV viral loads at the time of ART initiation had greater odds of a viral blip (figure). At study completion compared to PWH on non-nucleoside reverse transcriptase inhibitors (NNRTIs), those on integrase strand transfer inhibitors (INSTIs) had a reduced odds of blip, and those on protease inhibitors (PIs) had an increased odds of blip.
Conclusions
Nearly 25% of PWH experienced a viral blip over the study period. Factors associated with viral blips included older age, race/ethnicity, BMI, HIV acquisition risk, CD4 count and ART regimen. Further studies are needed to identify if blips are associated with subsequent HIV virologic failure.
Table or Figure
