Background:  Few jurisdictions assess whether all HIV-infected individuals eligible for ART are receiving treatment and whether those on ART achieve virologic suppression.

Methods:  Using San Francisco’s mature, accurate (>90% complete) HIV/AIDS surveillance system and mandatory laboratory reporting of HIV viral load, we calculated the percentage of all San Franciscans eligible for treatment (defined by CD4 count <350) and the percentage of all San Franciscans who are suppressed at 2 standard clinical cut-offs for achieving virologic suppression (viral load <75 and viral load <400). We calculated the Wald adjusted odds ratios for independent variables in 2 separate models using the different clinical cut-offs.

Results:  Of the 3556 individuals eligible for treatment based solely on CD4 <350, 3342(93.9%) were currently on treatment, 179 (5.0%) had never been treated, and 35 (1.0%) were not currently being treated. Of the 8144 individuals receiving treatment, 652(8%) were suppressed at viral load <75 and 4384 (54%) were suppressed at viral load <400. Higher log mean CD4 count was significantly associated with virologic suppression at both cut-off points:  viral load <75 (AOR 2.7, 95%CI 2.4, 3.3); viral load <400 (AOR 3.8; 3.4, 4.1]). Engagement in care (defined as seen at least once every 6 months for the past year) was associated with virologic suppression at the more stringent cut-off viral load <75 (AOR 2.2; 1.7, 2.7). Having ever changed one’s regimen was significantly associated with decreased odds of suppression only at viral load <400 (AOR 0.7; 0.6, 0.8). Being homeless was also associated with significantly decreased odds of suppression at both levels:  viral load <75 (AOR 0.5; 0.3, 0.94); viral load <400 (AOR 0.4; 0.3, 0.6). San Francisco neighborhoods with lowest median household incomes had significantly decreased odds of suppression only at viral load <400.

Conclusions:  In San Francisco, where the vast majority of persons meeting criteria for ART are on therapy, few are suppressed at viral load <75 and just more than half are suppressed at viral load <400. These population-level data highlight key areas for public health intervention such as support to maintain engagement in care and increasing access to housing that may maximize virologic response to ART.