Bacterial vaginosis and HIV acquisition: a meta-analysis of published studies

Abstract

Objectives To assess and summarize the published literature on the extent to which bacterial vaginosis (BV) may increase the risk of HIV acquisition. Design Meta-analysis of published studies. Methods MEDLINE and other electronic databases were systematically searched for eligible publications. The association between BV and incident HIV was separately analyzed from that between BV and prevalent HIV. The latter were further analyzed stratified by BV diagnostic method, HIV risk profile of the study population and whether or not adjusted estimates were presented. Results Twenty-three eligible publications were identified, including a total of 30,739 women. BV was associated with an increased risk of HIV acquisition in HIV-incidence studies (relative risk = 1.6, 95% CI: 1.2, 2.1). All but one of 21 HIV-prevalence studies reported estimates above the null. The latter results were heterogeneous and showed some evidence of funnel plot asymmetry, precluding the estimation of a single summary measure. The association between BV and HIV in prevalence studies appeared stronger for women without high-risk sexual behavior. Conclusions BV was consistently associated with an increased risk of HIV infection. High BV prevalence may result in a high number of HIV infections being attributable to BV. More prospective studies are needed to accurately evaluate the role of BV in HIV acquisition in low versus high risk women. Furthermore, randomized clinical trials may be worth considering to determine the effect of BV control measures on HIV acquisition.

Longitudinal Assessment of Pigtailed Macaque Lower Genital Tract Microbiota by Pyrosequencing Reveals Dissimilarity to the Genital Microbiota of Healthy Humans

“…13,14,16 Interestingly, many of the genera that were found at high levels in the pigtailed macaques are equivalent to those present in women with BV; Sneathia, Prevotella, Porphyromonas, and Atopobium sequences were found in the macaques frequently and are also often found in women with BV. 13,5 However, there were also several notable differences between the genital microbiota in the pigtailed macaques and BV. First, Gardnerella vaginalis is present at relatively high levels in many women with BV (average of approximately 5% of sequences), but was found in only three samples from two macaques and at relatively low levels (1.2%, 2.1%, and 6.5% of the sequences in those samples).…”

“…[1][2][3][4] The bacterial microbiota in the lower genital tract of pigtailed macaques could have an impact on vaginal infection with SIV or SHIV since in humans, epidemiological studies indicate that women with a genital microbiota that has the characteristics of bacterial vaginosis have a significantly increased susceptibility to sexual transmission of HIV. [5][6][7] Bacterial vaginosis (BV) is a condition in women in which the predominant genital bacterial types are a polymicrobial and variable mixture of bacteria including Gardnerella vaginalis, Prevotella, bacteria in the Order Clostridiales, and other anaerobes. 8 This spectrum of bacteria is quite different from that commonly found in women without BV, where the predominant type of bacteria is in most cases Lactobacillus species.…”

Lower Genital Tract Infections in HIV-Infected Women: Can We Afford to Miss?

“…A 2008 meta-analysis of 23 studies found out that bacterial vaginosis increased the risk of HIV infection by 60 % [9]. Studies have also reported increased shedding of HIV viral particles in the vaginal secretions of HIV-seropositive women with bacterial vaginosis which is critical to female to male transmission and vertical transmission of HIV [10,11].…”

The Barrier to HIV Transmission Provided by Genital Tract Lactobacillus Colonization

“…A number of studies have found that bacterial vaginosis (BV), a condition where levels of Lactobacillus are relatively decreased in the lower genital tract, increases the risk of a woman acquiring HIV during heterosexual contact. 8 A recent study by Cohen et al 9 found BV was also associated with an increased risk of female-to-male transmission.…”