Epidemiology 1 London School of Hygiene & Tropical Medicine, London, UK; 2 National Institute for Medical Research (NIMR), Mwanza, Tanzania; 3 African Medical and Research Foundation (AMREF), Mwanza, Tanzania; 4 St George’s Hospital, London, UK Correspondence to: Kathy Baisley, Department of Epidemiology & Population Health, Keppel Street, London, WC1E 7HT, UK; kathy.baisley@ lshtm.ac.uk Accepted 15 May 2009 Published Online First 26 May 2009 This paper is freely available online under the BMJ Journals unlocked scheme, see http:// sti.bmj.com/info/unlocked.dtl 370 Bacterial vaginosis in female facility workers in north-western Tanzania: prevalence and risk factors K Baisley,1,2 J Changalucha,2 H A Weiss,1 K Mugeye,3 D Everett,1,2 I Hambleton,1,2 P Hay,4 D Ross,1 C Tanton,1,2 T Chirwa,1,2 R Hayes,1 D Watson-Jones1,3 ABSTRACT Objectives: To determine prevalence of, and risk factors for, bacterial vaginosis (BV) among herpes simplex virus (HSV) 2 seropositive Tanzanian women at enrolment into a randomised, placebo-controlled trial of HSV suppressive treatment. Methods: 1305 HSV-2 seropositive women aged 16–35 years working in bars, guesthouses and similar facilities were interviewed, examined and tested for HIV, syphilis, Neisseria gonorrhoeae, Chlamydia trachomatis, BV, candidiasis and trichomoniasis. Factors associated with BV were analysed using logistic regression to estimate odds ratios and 95% confidence intervals. Results: BV prevalence was 62.9%; prevalence of Nugent score 9–10 was 16.1%. Independent risk factors for BV were work facility type, fewer dependents, increasing alcohol consumption, sex in the last week (adjusted OR 2.03; 95% CI 1.57 to 2.62), using cloths or cotton wool for menstrual hygiene, HIV (adjusted OR 1.41; 95% CI 1.09 to 1.83) and Trichomonas vaginalis infection. There was no association between BV and the frequency or method of vaginal cleansing. However, BV was less prevalent among women who reported inserting sub- stances to dry the vagina for sex (adjusted OR 0.44; 95% CI 0.25 to 0.75). Conclusion: BV was extremely prevalent among our study population of HSV-2 positive female facility workers in North-western Tanzania. Although recent sex was associated with increased BV prevalence, vaginal drying was associated with lower BV prevalence. Further studies of the effects of specific practices on vaginal flora are warranted. Bacterial vaginosis (BV) is one of the most common vaginal infections worldwide. It is char- acterised by vaginal flora changes, including a decrease in lactobacilli, particularly those that produce hydrogen peroxide, and an increase in anaerobic and facultative anaerobic bacteria. BV has been associated with a variety of adverse health outcomes, including preterm delivery,1 intrauterine infection,1 pelvic inflammatory disease (PID)2 and other gynaecological complications.3 BV may also increase susceptibility to HIV and other sexually transmitted infections (STIs),4–6 and in prospective studies BV has been associated with the acquisition of HIV and herpes simplex virus (HSV) type 2.7–11 BV may also facilitate HIV and HSV-2 transmission by increasing the frequency of genital shedding of the virus.12 The aetiology of BV remains poorly understood, although sexual activity and vaginal hygiene practices have been associated with BV.4 13–16 Reproductive hormones are also thought to play a role in the regulation of vaginal flora.17 18 In sub- Saharan Africa, the prevalence of BV is very high, ranging from 30–51% in community based stu- dies.6 10 A high prevalence has also been reported among African–American women with estimates of up to 50% in population-based surveys.19 The reasons for this are unclear. Prevention of BV, and any impact that this might have on reducing the risk of HIV acquisition, will depend in part on identification of risk factors for BV that are susceptible to interventions. We report on the factors associated with BV prevalence at baseline in a cohort of women at high risk of STI working in bars, guesthouses and similar facilities in Tanzania. These women were enrolled into a trial of the effect of HSV-2 suppressive treatment on HIV incidence, and on genital HIV and HSV-2 viral shedding in women who are HIV positive. MATERIALS AND METHODS Study population A randomised, double-blind, placebo-controlled trial of acyclovir 400 mg twice daily suppressive treatment was conducted in women HSV-2 seropositive in the Lake Victoria region of Tanzania. In total, 1305 women aged 16–35 years working in bars, guesthouses and similar facilities were enrolled in three phases from January 2004 to May 2006. Trial procedures have been described previously.20 Screening, enrolment and 3-monthly follow-up visits were conducted at mobile clinics established in 19 communities in high HIV- transmission areas. Women were followed for 12– 30 months depending on phase of enrolment. At screening, after informed consent, partici- pants were tested for antibodies to HSV-2 and HIV, and interviewed about sociodemographic details, sexual behaviour and intravaginal practices (IVP). Eligible women were given an appointment to attend the mobile clinic 8–12 weeks later; women were asked to avoid vaginal cleansing before attending the visit. To be eligible, women had to be HSV-2 seropositive, have no history of epilepsy, able to give informed consent, not planning to move out of the study site, not breastfeeding and not pregnant or planning preg- nancy during follow-up. At enrolment, participants were tested for pregnancy and were asked about recent sexual behaviour and IVP. Women were examined for symptoms of reproductive tract infections (RTI), and blood and genital samples were collected. Participants were offered syndromic management Sex Transm Infect 2009;85:370–375. doi:10.1136/sti.2008.035543