Bacterial vaginosis in HIV-1 infected females was
associated with the risk for transmission among male partners. Therefore,
Craig R. Cohen, MD, MPH, and colleagues suggest that normalization of
vaginal flora in HIV-1 infected women may decrease virus transmission.
“While bacterial vaginosis increases HIV-1 shedding from the female
genital tract, its impact on HIV-1 transmission to male partners has not been
assessed,” according to the study abstract presented at the 6th IAS
Conference on HIV Pathogenesis, Treatment and Prevention in Rome.
In the prospective study, Cohen, of the University of
California, San Francisco, and colleagues measured the effect of bacterial
vaginosis compared with normal vaginal flora and the risk for female-to-male HIV-1 transmission.
Craig R. Cohen, MD, MPH
The cohort included 2,236 HIV-1 seronegative men with an
HIV-1 seropositive female partner recruited from seven sub-Saharan African
countries. The researchers used Nugent’s criteria to collect and evaluate
vaginal Gram’s stains every 3 months, for up to 2 years.
Compared with an HIV-1 incidence of 2.87/100
person-years (HR=3.09; 95% CI, 1.58-6.06) among men whose female partners had
bacterial vaginosis 3 months before detecting HIV-1 seroconversion, HIV-1
incidence was 0.88/100 person-years in men whose female partners had normal
After adjusting for socio-demographic factors, sexual
behavior, male circumcision, sexually transmitted infections at enrollment, and
pregnancy and plasma
HIV-1 RNA in female partners, researchers found that
men whose female partner had bacterial vaginosis 3 months before identifying
HIV-1 seroconversion (HR=2.83; 95%CI, 1.29-6.22) and at the same visit
(HR=3.64; 95% CI, 1.68-7.90) had an increased incidence of HIV-1 compared with
men whose female partners had normal vaginal flora.
For more information:
- Cohen CR. # MOAC0202. Presented at: The 6th IAS Conference on HIV
Pathogenesis, Treatment and Prevention; Rome; July 17-20, 2011.
There are increasingly convincing data that the state of vaginal
microenvironment is very important in determining the risk of HIV heterosexual
transmission from men to women. Several investigators have established that
bacterial vaginosis (BV) increases the risk HIV infection by ~1.6-fold. The
Rakai Community Cohort Study found that pregnancy conferred a 2.1-fold
increased risk of HIV infection. Data on hormonal contraceptives have been
inconsistent, but have suggested that progesterone dominant contraception may
increase the rate of HIV acquisition. Studies focusing on post-menopausal women
with atrophic vaginitis have not been done. For unclear reasons, grants
requesting funds for such work have not been awarded or even scored. However,
observational data and the physiology of the vaginal epithelium again suggest
that post-menopausal women are at increased risk of HIV acquisition.
Very few studies which focus on the vaginal microenvironment and female
to male HIV transmission have been performed. At the International AIDS Society
meeting in Rome, Craig R. Cohen presented data from a study, which measured the
impact of BV on female-to-male HIV transmission. Over 2,200 HIV negative men
and their HIV positive female partners were followed for an average of over 5
years. Recent BV in the female partner increased the rate of HIV transmission
by 3-fold. The mechanism for this increased rate of transmission is not
understood, since the effect of BV on HIV vaginal shedding was modest.
Monitoring the vaginal flora of HIV infected women in monogamous relationships
with uninfected men and treating those with BV may have a significant effect on
HIV transmission. The recent data from HPTN 052 show that ART is very effective
at preventing HIV transmission in this same scenario. Monitoring and treating
HIV positive women for BV may be more easily achieved in the short run than
providing HIV treatment in resource poor settings.
– Stephen Smith, MD
Infectious Disease News Editorial Board member
Disclosure: Dr. Smith reports no relevant financial