Plasma viremia in human immunodeficiency virus infection.

To determine which markers of human immunodeficiency virus type 1 (HIV) replication correlate most closely with progressive disease, we compared the following: (1) the frequency of isolation of HIV from peripheral-blood mononuclear cells (PBMC), (2) the frequency of isolation of the virus from cell-free plasma (plasma viremia), (3) the presence and titer of p24 antigen in plasma, and (4) the presence and titer of antibody to p24 antigen. We studied 213 persons who were positive for HIV antibody and 71 who were negative. HIV was isolated from PBMC from 207 of the 213 antibody-positive patients (97 percent), regardless of the clinical stage of the infection. Plasma viremia, in contrast, was correlated with the clinical stage of the infection. It was detected in 11 of 48 patients (23 percent) with asymptomatic infection, 32 of 71 (45 percent) in Class IVa of the Centers for Disease Control (those with AIDS-related complex), and 75 of 92 (82 percent) in Class IVc (those with AIDS) (P less than 0.01). Plasma HIV titers ranged from 10(0) to 10(4.3) and rose from a mean of 10(1.4) in asymptomatic patients to 10(2.5) in those with AIDS (P less than 0.02). Only 45 percent of patients with plasma viremia had HIV p24 antigen in either serum or plasma, and no correlation was found between the amount of p24 antigen in plasma and the plasma HIV titers. Follow-up tests indicated that plasma viremia was associated with a more marked decline in the CD4-lymphocyte cell count and the development of symptomatic disease (P = 0.034). We conclude that plasma viremia is a more sensitive virologic marker of the clinical stage of HIV infection and viral replication than the presence of p24 antigen or antibody in plasma. Not only whole blood but cell-free plasma from HIV-infected patients should be considered potentially infectious.

Isolation of human immunodeficiency virus from genital ulcers in Nairobi prostitutes.

Recent epidemiologic studies have implicated genital/anorectal ulcer disease as an important cofactor for acquisition and transmission of human immunodeficiency virus (HIV) during sexual intercourse. To better understand the mechanism for the association between genital ulcers and HIV, exudates from 62 genital ulcers of 56 HIV-seropositive prostitutes in Nairobi (Kenya) were cultured for HIV. Twenty-six ulcer cultures could not be evaluated for the presence of HIV because of bacterial or fungal contamination. HIV was isolated from 4 (11%) of the 36 remaining uncontaminated ulcer cultures (2 introital, 1 vaginal, and 1 cervical) from 4 separate women. HIV was isolated from the cervical os from only 2 of the 4 women. HIV p24 antigen was detected in exudate from 1 of the 4 culture-positive ulcers and 0 of 32 culture-negative ulcers. Genital ulcers in seropositive patients should be regarded as potential sources of HIV, which could be important in transmission of HIV during intercourse. Public health measures aimed at controlling sexually transmitted genital ulcer diseases should be an integral part of acquired immunodeficiency syndrome (AIDS) prevention programs.