A quarter of HIV-positive women with an undetectable HIV viral load in their blood still had detectable HIV in their vaginal secretions, according to Italian research published in the October edition of AIDS.
Between 1995 and 2001, investigators recruited 122 women to a study to determine the factors associated with cervicovaginal shedding of HIV. The study members had an average age of 33 years, and 35% had an AIDS diagnosis. To be included in the study women had to be free from genital bleeding or discharge, have no symptoms of sexually transmitted infections, have abstained from sex 48 hours before cervicovaginal samples were obtained, and not be menstruating.
The women were divided into one of four categories according to their experience of anti-HIV therapy. Category one included women who received HAART; category two comprised women who had received therapy with one or two NRTIs; category three was made up of study participants who were taking a break from anti-HIV treatment; and finally, category four comprised women who were naïve to therapy.
Paired samples of blood plasma and cervicovaginal lavage were obtained and tested using an HIV viral load assay which had a lower limit of detection of 80 copies/mL.
Of the 122 women enrolled to the study, 94 (77%) had detectable HIV in plasma, and 71% had detectable HIV in their vaginal secretions. When the investigators analysed these finding further they found a correlation between detectable HIV in plasma and in vaginal secretions. Amongst of the treatment naïve women enrolled in the study, 83% had detectable HIV in plasma and 79% in their vaginal secretions. Of the women taking a break from treatment, all had detectable HIV in both plasma and their vagina. Of the women on non-HAART regimens, 73% had detectable plasma viral load and 78% detectable HIV in vaginal secretions. Finally, 50% of women taking HAART had a detectable plasma viral load and 40% detectable HIV in vaginal fluids.
Detectable viral load in plasma was significantly associated with a decreased CD4 cell count (OR 0.54 for each 100 cells/mm3, p=0.001), injecting drug use (OR 6.27, p=0.013) and taking anti-HIV therapy compared to being treatment naive (p
As for detectable HIV in cervicovaginal secretions, the investigators found that this was significantly associated with decreased CD4 cell count (OR 0.79 for each 100 cells, p=0.029), and with HAART treatment compared to being treatment naive (p=0.001).
”We observed that the presence of genital HIV shedding was positively correlated with plasma viraemia”, note the investigators. They add, however, “25% of women with undetectable viral load in plasma showed a cervicovaginal shedding of HIV”. Of these four women were treatment-naïve; and three were taking non-HAART treatment. The rest were taking HAART.
In 14 women the opposite was true – an undetectable HIV viral load in their cervicovaginal secretions, but a detectable viral load in their plasma. Six of these women were naïve to therapy, and six were taking HAART.
These results, taken together, the investigators conclude, “indicate that in general the viral load in genital secretions reflects the situation in the blood…as a rule, an antiretroviral treatment capable of suppressing HIV in the blood also suppresses HIV viral shedding at the genital site and thus antiretrovirals may be considered useful tools to reduce viral transmission.”
The researchers caution however, that this is not always the case, as a quarter of women with an undetectable viral load in their blood were still shedding HIV in their vagina. This “indicates that caution is required in judging infectivity of women on the basis of plasma viral load only, in both sexual and mother-to-child situations.”
Further information on this website
Infectiousness - factsheet
Viral load and CD4 - booklet in the information for HIV-positive people series
Fiore JR et al. Correlates of HIV-1 shedding in cervicovaginal secretions and effects of antiretroviral therapies. AIDS 17: 2169 – 2176, 2003.