P1-S5.29 Relationship between incident bacterial vaginosis, gonorrhoea and chlamydial infection among women attending a sexually transmitted disease clinic
Authors: Gallo M , Macaluso M , Warner L , Fleenor M , Hook E , Brill I , Weaver M 
Published: July 2011

Background

Interactions between bacterial vaginosis (BV) and inflammatory sexually transmitted infections, such as gonorrhoea and chlamydial infection, are not well understood. Furthermore, evidence regarding the sexual transmission of BV is equivocal.

Methods

We assessed associations between incident BV and incident gonorrhoea and/or chlamydial infection (gonorrhoea/chlamydia), as well as similarities in associations for the two processes, among 645 women attending a sexually transmitted disease clinic in Alabama, who were followed prospectively for 6 months in 1995–1998. We also identified predictors of both incident BV and gonorrhoea/chlamydia and used bivariate logistic regression to determine whether these predictors differed.

Results

Participants completed 3188 monthly, follow-up visits. Several factors associated with incident BV involved sexual intercourse: young age (<16 years) at first intercourse (adjusted OR [aOR]: 1.5; 95% CI 1.1 to 1.9), recent drug use during sex (aOR: 1.7; 95% CI 1.2 to 2.5), prevalent trichomoniasis (aOR: 2.8; 95% CI: 1.7 to 4.6) and incident syphilis (aOR: 9.7; 95% CI 1.9 to 48.4). Few statistical differences between potential factors for BV and gonorrhoea/chlamydia emerged. Specifically, in the adjusted bivariate analysis, we found no evidence that the four sex-related risk factors for incident BV (along with unprotected vaginal acts, which was a risk factor for incident gonorrhoea/chlamydia) differed in their associations with the two study outcomes. We found evidence that incident BV preceded the acquisition of gonorrhoea/chlamydia (adjusted pairwise OR [aPOR]: 1.6; 95% CI 1.1 to 2.3), and gonorrhoea/chlamydia appeared to precede the acquisition of BV (aPOR: 2.4; 95% CI 1.7 to 3.5).

Conclusions

Study findings provide support for the interpretation that BV is sexually transmitted. We found temporal relationships between BV and gonorrhoea/chlamydia in both directions, which suggests that treating one condition might confer protection against the other. However, this effect needs to be demonstrated in future clinical studies.

Abstract P1-S5.29 Table 1

Multivariable analysis of factors associated with incident bacterial vaginosis and incident gonorrhoea and/or chlamydial infection*

FactorsIncident BVIncident GC/CTp value‡aOR† (95% CI)aOR† (95% CI)TIME-INDEPENDENTMarital status Married or cohabitingreferentreferent0.01 Not married or cohabiting1.0 (0.6 to 1.6)7.3 (1.7 to 31.7)Race Black2.4 (1.3 to 4.3)0.9 (0.4 to 1.7)0.01 White, otherreferentreferentAge at first intercourse <16 years1.5 (1.1 to 1.9)1.6 (1.0 to 2.4)0.78 ≥16 yearsreferentReferentRecent drug use during sex Usually or sometimes1.7 (1.2 to 2.5)1.7 (0.9 to 3.1)1.0 Rarely or neverReferentReferentTIME-DEPENDENTPrevalent trichomoniasis Yes2.8 (1.7 to 4.6)1.6 (0.8 to 3.4)0.22 NoReferentReferentIncident syphilis Yes9.7 (1.9 to 48.4)5.3 (1.1 to 25.6)0.52 NoReferentReferentPrevalent candidiasis YesReferentReferent0.03 No0.9 (0.6 to 1.4)3.5 (1.2 to 10.6)In first week of menstrual cycle YesReferentReferent0.01 No0.8 (0.6 to 1.2)2.4 (1.2 to 5.0)Unprotected vaginal acts in past month 0ReferentReferent0.20 ≥11.2 (0.9 to 1.6)1.6 (1.1 to 2.4)Current oral contraceptive use YesReferentReferent0.03 No1.7 (1.1 to 2.4)0.9 (0.6 to 1.5)*

Both outcomes estimated from a single model using generalised estimating equations and alternating logistic regression.

†

Adjusted for all characteristics in Abstract P1-S5.29table 1.

‡

p Value for difference in the associations between the factor and the two disease outcomes.

BV, bacterial vaginosis; GC/CT, gonorrhoea and/or chlamydial infection; aOR, adjusted OR.