Abstract: The present invention relates to a new HIV status of a patient called “latent viral load.” To measure the “latent viral load,” in accordance with a preferred embodiment of the present invention, a population of sample cells is obtained from a desired source, such as an infected patient. The sample cell population is depleted of overtly infected cells and cells harboring active virus, to produce a subset of “resting cells” comprising uninfected and latently-infected cells. This subset is treated with an agent and/or condition that activates the latent virus in the host cell genome and results in a productive infection. The thus-produced infection reflects the “latent viral load” of the host because it reveals the presence of quiescent virus in cells. The latent viral load is useful in assessing a patient's disease status and the efficacy of highly active antiretroviral therapy and other treatment protocols.