Is bacterial vaginosis just the tip of the iceberg as to the risk of HIV related to vaginal flora abnormalities ? Presenter: Guédou F. A. MD, MSc, PhD Co-authors: Van Damme L, Mirembe F, Solomon S, Becker M, Deese J, Crucitti T, Taylor D, Alary M 1 Afri-Can Forum Entebbe January 2013

Overview Background Objectives Methods and materials Results Discussion Conclusion 2

Background(1) Bacterial Vaginosis (BV) is a polymicrobial infection resulting from the replacement of lactobacilli of the normal vaginal flora by a variety of bacteria, predominantly anaerobic The main challenge of BV to date is that of the identification of its causative agent so that the current consensus is that a polymicrobial infection 3

Background (2) Conventionally, BV is diagnosed: Clinically on Amsel’s criteria; Biologically with Nugent’score: normal flora (NS = 0-3); intermediate flora (NS = 4-6); BV (NS = 7-10) 4

Background (3) BV = most common genital infection worldwide Higher prevalence in developing countries (DC): between 9% and 50%; 70% among female sex workers (FSW) 5

But what justifies the present work is that the role of BV in HIV acquisition or transmission has been strongly suggested by some studies Since BV has such a high prevalence among FSWs, even a modest RR substantial attributable risk for HIV Background (4)

Background (5) This is of uppermost interest when considering the role of core group played by FSWs in the dynamic of HIV epidemics in DC and particularly in Sub-Saharan Africa In addition, most studies that have examined this association have classified “BV” as (BV vs. non-BV) Very little attention has been paid to the possible role of intermediate vaginal flora (IVF) in this association 7

Objectives To investigate the association between HIV and respectively IVF and BV, among FSW screened prior to enrolment in the Cellulose sulfate trial To compare the strengths of these two associations 8

Chennai Mudhol/Jhamkandi (India): (2) Kampala (Uganda): (1) Durban (South Africa): (1) Cotonou (Benin): (1) Uganda Benin Settings: Sites of the CS trial Materials and Methods (1)

Participants selection: Eligibility criteria: Potential participant in the SC trial 18 years or older HIV high risk woman (≥ 3 different sexual partners in the last 3 months and ≥ 3 sexual acts/week) Data available for both BV and HIV Informed consent for screening Materials and Methods (2)

Data collection Materials and Methods (3) Interview: socio-demo. and behavioral data Gynecological Exam: clinical data Blood and cervico-vaginal swabs : HIV: HIV antibodies test BV: Gram and Nugent score (NS) Gonorrhea and Chlamydia: SDA ( Strand DNA Amplification ) Syphilis: RPR confirmed with TPHA Trichomoniasis (TV) and Candidiasis: Wet mount

Statistical analyses Log binomial regression to model HIV prevalence with respect to vaginal flora abnormalities: 2 categories: BV vs. Non-BV 3 categories : normal (reference), IVF and BV (Comparison of BV and IVF prevalence ratios) Bivariate analyses (controlling for site) Multivariate analyses (adjustment) Materials and Methods(4) 12

Results: (1) 13 Characteristics of 1367 FSW screened at 2 African and 2 Indian sites of a randomized microbicide clinical trial on cellulose sulfate gel Characteristicsn or median(%) ou IQR Number of sexual partners /last 3 months80[25 – 270] Number of sexual acts / last 7 days8[4 – 20] Condom use at the last sexual act1061(77.7) Intra-vaginal cleansing1340(98.0) Current STI or lower genital infections: HIV Gonorrhea Chlamydia Trichomoniasis Candidiasis Bacterial vaginosis Intermediate vaginal flora Syphilis (27.0) (8.1) (5.9) (6.7) (30.8) (47.6) (19.2) (6.0)

Results (2) 14 Multivariate analysis between vaginal flora abnormalities and HIV Factors HIV prevalence by exposition level Ajusted prevalence ratio (aPR)* ni/Ni (%) aPR (95%CI)p-value Vaginal flora abnormalities (in 2 cat.): Bacterial vaginosis (NS= 7-10) Non-Bacterial vaginosis (NS= 0-6) 192/651 (29.5) 177/716 (24.7) 1.21 ( ) 1.00 – 0.02 – Vaginal flora abnormalities (in 3 cat.): Bacterial vaginosis (NS= 7-10) Intermediate vaginal flora (NS= 4-6) Normal vaginal flora (NS= 0-3) 192/651 (29.5) 84/262 (32.1) 93/454 (20.5) 1.48 ( ) 1.56 ( ) 1.00 – – *The aPR from the 2 types of categorisation were obtained from separate multivarite models but including the same covariates (site, education level, STI history, occupation other than Sex work, oral sex, female sterilisation, gonorrhea and vaginal candidiasis)

Discussion (1) The aPR obtained using women with NVF as reference was substantially higher than that obtained using women without BV as reference This is due to the fact that HIV prevalence among women with IVF was significantly higher than that of women with NVF: aPR = 1.56 (95% CI = , p = ) The use of all women without BV (NVF/IVF) as a reference to measure the increase in HIV risk associated with BV could lead to its underestimation 15

Discussion (2) In addition, the strength of the association obtained with IVF was similar to that obtained with the BV (p = ) This is in contrast with the trend of monotonic increase found in most studies that have examined the association between HIV and vaginal flora abnormalities 16

Discussion (3): Direction of the association? BV may increase the risk of HIV Mobilization of HIV target cells Weakening of the vaginal epithelial barrier HIV may increase the risk of BV Immunosuppression? But no significant association between HIV and other STIs! A risk factor common to HIV and BV (not / insufficiently controlled by analysis) 17

Discussion (4): the study limits Cross-sectional design 124 eligible FSW excluded (lack of data on BV) Inability to control for HSV-2, alcohol Possibility of inaccuracy for some data: Vaginal douching (quantification) Number of sexual partners (memory) Condom use (social desirability) 18

Discussion (5): Strenghts of the study Clinical trial settings: Large sample size An international quality control system Use of the current gold standard for BV diagnosis Use of log-binomial regression: which enabled a better approximation of the relative risk 19

Conclusions The results of this study suggest that: BV represents only a part of the vaginal flora abnormalities associated with an increased risk of HIV; IVF is associated with HIV as stronger as BV Need of prospective studies to confirm findings Implication for HIV prevention: Controlling vaginal flora abnormalities (not just BV) among FSWs may be an untapped strategy to curb HIV epidemic, particularly in countries with concentrated epidemic 20

Acknowledgments (1) Trial participants Cotonou Team (Benin): Clinical team: I. Minani; N. Geraldo; G. Ainan; C. Assogba; C. Gbenafa Lab team: M. Loembe; E. Goma; G. Ahotin; L. Djossou; N. Tata Sociology team: O. Azonnadou, J. Agonmounon, F. Mito-Yobo Field team: G. Batona et coll. Canada Team(CHU of Quebec) : M. Belleau, J. Leroux, J. Begin, L. Pagé Other sites: Lusaka (Ouganda): F. Mirembe et al. Chennai (Inde): S. Solomon et al. Mudhol/Jhamkandi (Inde): M. Becker et al. 21

Aknowledgments (2) International Team: CONRAD (VA, USA): L. Van Damme (PI); FHI (NC, USA): J. Deese; D. Taylor; ITM (Antwerrp, Belgium) : T. Crucitti Sponsor: CONRAD (USA) Funders: USAID Fondation Bill Gates & Melinda 22

Thanks for your kind attention