CHARLESTON, S.C. — Certain vaginal isolates may affect the quantity of HIV RNA in cervicovaginal lavage, Jane Hitti, M.D., reported at the annual meeting of the Infectious Diseases Society for Obstetrics and Gynecology.
Factors affecting the HIV RNA concentrations are important, because genital viral load is a major determinant of sexual and perinatal HIV transmission, noted Dr. Hitti of the University of Washington, Seattle.
She reported on 38 HIV-positive women who completed 163 study visits. Vaginal cultures, cervicovaginal lavage, and plasma were collected at each visit for HIV RNA quantitation.
Hydrogen peroxide-producing lactobacilli were associated with a significant decrease in cervicovaginal lavage HIV RNA concentrations, and Trichomonas vaginalis, Prevotella bivia, Mycoplasma hominis, and other anaerobes were associated with increases in cervicovaginal lavage HIV RNA concentrations.
Of 163 CVL samples, 95 had detectable HIV RNA, and the levels correlated significantly with plasma HIV RNA levels, she said.
After adjustment for log plasma HIV RNA, the log difference in cervicovaginal lavage HIV RNA was significant for H2O2 lactobacillus and T. vaginalis. Increased cervicovaginal lavage HIV RNA concentrations also were associated, although not significantly, with M. hominis, P. bivia, black gram-negative rods, Candida albicans, and bacterial vaginosis or intermediate flora.
Also, cervicovaginal lavage HIV RNA concentrations were increased with higher vaginal concentrations of IL-8 in this study, Dr. Hitti noted.
Several vaginal isolates appear to directly influence cervicovaginal lavage viral load, and the effects appear to be independent of plasma viral load, she concluded, noting that an antibiotic treatment trial is underway to determine whether treatment for bacterial vaginosis and associated infections will decrease genital viral load.
“A very logical next step would be looking at ways to augment endogenous lactobacilli and looking at what effects that has,” she said.
The prevalence of H2O2-producing lactobacilli is lower than what has been reported among HIV-negative women, even in the presence of bacterial vaginosis, she explained.