Factors associated with nucleic acids related to human immunodeficiency virus type 1 in cervico-vaginal secretions

Objective To assess HIV-related nucleic acids in cervico-vaginal secretions and the factors associated with them.

Design Observational study.

Setting Department of Obstetrics and Gynaecology, University of Pavia, Italy.

Population HIV-positive patients attending a cytology service.

Methods Paired blood and cervico-vaginal lavage samples were obtained from 122 known HIV-seropositive patients during periodic visits for cytologic screening for lower genital tract neoplasia. Vaginal specimens for the diagnosis of bacterial vaginosis, trichomonas vaginalis and candida infection were also obtained. HIV-1-RNA in plasma, proviral HIV-1-DNA, cell associated and cell-free HIV-1 RNA in cervico-vaginal secretions were quantitatively evaluated by competitive polymerase chain reaction (c-PCR) and reverse transcriptase PCR (cRT-PCR).

Main outcome measure Prevalences of HIV related nucleic acids in cervico-vaginal secretions and their univariate and multivariate associations with clinical variables.

Results Proviral HIV-1 DNA, cell-associated and cell-free HIV-1 RNA were detected in 50% (61/122), 37.7% (46/122) and 32.8% (40/122) of the patients, respectively. In logistic regression analysis, the presence of HIV-1 RNA in blood was the factor which correlated best with the detection of HIV-1 DNA (OR = 5.48, 95% CI=2.28-13.20), cell-associated (OR = 4.85; 95% CI = 1.89–12.45) and cell-free HIV-1 RNA (OR = 4.63, 95% CI = 1.74–12.33) in cervico-vaginal samples. However, between 20% and to 35% of patients who tested negative for blood HIV-1 RNA were positive for either HIV-1 DNA or HIV-1 RNA detection in cervico-vaginal lavages. Bacterial vaginosis was associated with an increased prevalence of cell-associated (OR=3.58, 95% CI = 1.22–10.54) and cell-free HIV-1 RNA (OR = 2.94, 95% CI = 1.0–8.7) detection in cervico-vaginal secretions. Additional factors associated with increased prevalence of HIV-1 RNA detection were advanced stage of HIV disease and vulvovaginal candidiasis.

Conclusions Although the presence of HIV-1 RNA in blood is the factor which correlates best with the detection of HIV-related nucleic acids in cervico-vaginal secretions, the shedding of HIV in the genital tract can occur in 20-30% of non-viremic subjects. Bacterial vaginosis and candida infection could have a facilitating role in local HIV viral replication and shedding.