Factors Associated with Increased Levels of Human Immunodeficiency Virus Type 1 DNA in Semen

Human immunodeficiency virus type 1 (HIV-1)-infected cells have been isolated from semen and may be a major source of transmissible virus. Quantitative polymerase chain reaction (PCR) assay was used to determine HIV proviral DNA load in cellular fractions of semen from 74 antiviral therapy-naive HIV-1-seropositive men and 53 paired blood samples. HIV-1 DNA was detected in 65% of semen (range: <10-5000 copies/mL) and 100% of blood samples (range: 20-2500 copies/mL). HIV-1 DNA copy numbers in semen correlated significantly with those in blood, but for most cases, the concentration of blood HIV-1 DNA was higher (mean blood-to-semen ratio = 2.9). Factors associated with elevated HIV-1 provirus levels in semen included reduced peripheral CD4 cell count and asymptomatic genital tract inflammation (>10(6) white blood cells/mL of semen). These data provide evidence that genital tract inflammation and reduced peripheral CD4 cell count may be associated with enhanced sexual transmission of HIV-1 because of increased numbers of HIV-1-infected cells in semen.