Figure 3. Estimated mean values of true population viral load, community viral load, and monitored viral load as defined by CDC.

Population viral load = mean viral load among all HIV-infected individuals (theoretical; currently unobserved). Monitored viral load = estimated mean viral load as measurable in settings with VL data available only for persons in care. Community viral load = estimated mean viral load for persons in and out of care, excluding undiagnosed, as measured in a best-case setting (based on San Francisco data). A detailed description of the methods used in generating the figure is contained in the supplemental material. Briefly, figure assumptions and calculations were based on published estimates of the proportions of HIV-infected populations in key subgroups along the HIV care cascade (ref [1] for San Francisco, ref [14] for the US overall), proportions of infection-unaware persons with acute infection [18, 19], and mean viral loads in each sub-group [1, 18, 20].