***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVES To examine the relationship between use of oral contraceptive pills or depot medroxyprogesterone acetate and sexually transmitted disease acquisition . STUDY DESIGN Prospect i ve cohort included 948 Kenyan prostitutes . Multivariate And ersen-Gill proportional hazards models were constructed , adjusting for sexual behavioral and demographic variables . RESULTS When compared with women who were using no contraception , users of oral contraceptive pills were at increased risk for acquisition of chlamydia ( hazard ratio , 1.8 ; 95 % confidence interval , 1.1 - 2.9 ) and vaginal c and idiasis ( hazard ratio , 1.5 ; 95 % confidence interval , 1.2 - 1.9 ) and at decreased risk for bacterial vaginosis ( hazard ratio , 0.8 ; 95 % confidence interval , 0.7 - 1.0 ) . Women using depot medroxyprogesterone acetate had significantly increased risk of chlamydia infection ( hazard ratio , 1.6 ; 95 % confidence interval , 1.1 - 2.4 ) and significantly decreased risk of bacterial vaginosis ( hazard ratio , 0.7 ; 95 % confidence interval , 0.5 - 0.8 ) , trichomoniasis ( hazard ratio , 0.6 ; 95 % confidence interval , 0.4 - 1.0 ) , and pelvic inflammatory disease ( hazard ratio , 0.4 ; 95 % confidence interval , 0.2 - 0.7 ) . Consistent condom use was associated with significantly decreased risk of gonorrhea , chlamydia , genital ulcer disease , bacterial vaginosis , and pelvic inflammatory disease . CONCLUSIONS The use of oral or injectable hormonal contraception altered susceptibility to sexually transmitted diseases , which may in turn influence transmission of human immunodeficiency virus type 1 . Consistent condom use was protective with regards to sexually transmitted disease and should be encouraged for the prevention of sexually transmitted disease and human immunodeficiency virus type 1 among women who use hormonal contraception Background To determine if oral metronidazole ( MTZ-400 mg bid ) with 2 % vaginal clindamycin-cream ( Clind ) or a Lactobacillus acidophilus vaginal-probiotic containing oestriol ( Prob ) reduces 6-month bacterial vaginosis ( BV ) recurrence . Methods Double-blind placebo-controlled parallel-group single-site study with balanced r and omization ( 1∶1∶1 ) conducted at Melbourne Sexual Health Centre , Australia . Participants with symptomatic BV [ Nugent Score ( NS ) = 7–10 or ≥3 Amsel 's criteria and NS = 4–10 ] , were r and omly allocated to MTZ-Clind , MTZ-Prob or MTZ-Placebo and assessed at 1,2,3 and 6 months . MTZ and Clind were administered for 7 days and Prob and Placebo for 12 days . Primary outcome was BV recurrence ( NS of 7–10 ) on self-collected vaginal-swabs over 6-months . Cumulative BV recurrence rates were compared between groups by Chi-squared statistics . Kaplan-Meier , log rank and Cox regression analyses were used to compare time until and risk of BV recurrence between groups . Results 450 18–50 year old females were r and omized and 408 ( 91 % ) , equally distributed between groups , provided ≥1 NS post-r and omization and were included in analyses ; 42 ( 9 % ) participants with no post-r and omization data were excluded . Six-month retention rates were 78 % ( n = 351 ) . One-month BV recurrence ( NS 7–10 ) rates were 3.6 % ( 5/140 ) , 6.8 % ( 9/133 ) and 9.6 % ( 13/135 ) in the MTZ-Clind , MTZ-Prob and MTZ-Placebo groups respectively , p = 0.13 . Hazard ratios ( HR ) for BV recurrence at one-month , adjusted for adherence to vaginal therapy , were 0.43 ( 95%CI 0.15–1.22 ) and 0.75 ( 95 % CI 0.32–1.76 ) in the MTZ-Clind and MTZ-Prob groups compared to MTZ-Plac respectively . Cumulative 6-month BV recurrence was 28.2 % ; ( 95%CI 24.0–32.7 % ) with no difference between groups , p = 0.82 ; HRs for 6-month BV recurrence for MTZ-Clind and MTZ-Prob compared to MTZ-Plac , adjusted for adherence to vaginal therapy were 1.09(95 % CI = 0.70–1.70 ) and 1.03(95 % CI = 0.65–1.63 ) , respectively . No serious adverse events occurred . Conclusion Combining the recommended first line therapies of oral metronidazole and vaginal clindamycin , or oral metronidazole with an extended-course of a commercially available vaginal-L.acidophilus probiotic , does not reduce BV recurrence . Trial Registration ANZCTR.org.au 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 r and omised ,  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 , c and idiasis 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 substances 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 practice s on vaginal flora are warranted BACKGROUND Hormonal contraceptives are used widely but their effects on HIV-1 risk are unclear . We aim ed to assess the association between hormonal contraceptive use and risk of HIV-1 acquisition  by women and HIV-1 transmission from HIV-1-infected women to their male partners . METHODS In this prospect i ve study , we followed up 3790 heterosexual HIV-1-serodiscordant couples participating in two longitudinal studies of HIV-1 incidence in seven African countries . Among  injectable and oral hormonal contraceptive users and non-users , we compared rates of HIV-1 acquisition by women and HIV-1 transmission from women to men . The primary outcome measure was HIV-1 seroconversion . We used Cox proportional hazards regression and marginal structural modelling to assess the effect of contraceptive use on HIV-1 risk . FINDINGS Among 1314 couples in which the HIV-1-seronegative partner was female ( median follow-up 18·0 [ IQR 12·6 - 24·2 ] months ) , rates of HIV-1 acquisition were 6·61 per 100 person-years in women who used hormonal contraception and 3·78 per 100 person-years in those who did not ( adjusted hazard ratio 1·98 , 95 % CI 1·06 - 3·68 , p=0·03 ) . Among 2476 couples in which the HIV-1-seronegative partner was male ( median follow-up 18·7 [ IQR 12·8 - 24·2 ] months ) , rates of HIV-1 transmission from women to men were 2·61 per 100 person-years in couples in which women used hormonal contraception and 1·51 per 100 person-years in couples in which women did not use hormonal contraception ( adjusted hazard ratio 1·97 , 95 % CI 1·12 - 3·45 , p=0·02 ) . Marginal structural model analyses generated much the same results to the Cox proportional hazards regression . INTERPRETATION Women should be counselled about potentially increased risk of HIV-1 acquisition and transmission  with hormonal contraception , especially injectable methods , and about the importance of dual protection with condoms to decrease HIV-1 risk  . Non-hormonal or low-dose hormonal contraceptive methods should be considered for women with or at-risk for HIV-1 . FUNDING US National Institutes of Health and the Bill & Melinda Gates Foundation Background The effect of storage conditions on the microbiome  and metabolite composition of human biological sample s has not been thoroughly investigated as a potential source of bias . We evaluated the effect of two common storage conditions used in clinical trials on the bacterial and metabolite composition of the vaginal microbiota using pyrosequencing of barcoded 16S rRNA gene sequencing and 1H-NMR analyses . Methodology /Principal Findings Eight women were enrolled and four mid-vaginal swabs were collected by a physician from each woman . The sample s were either processed immediately , stored at −80 ° C for 4 weeks or at −20 ° C for 1 week followed by transfer to −80 ° C for another 4 weeks prior to analysis . Statistical methods , including Kolmogorovo-Smirnov and Wilcoxon tests , were performed to evaluate the differences in vaginal bacterial community composition and metabolites between sample s stored under different conditions . The results showed that there were no significant differences between sample s processed immediately after collection or stored for varying duration s. 1H-NMR analysis of the small molecule metabolites in vaginal secretions indicated that high levels of lactic acid were associated with Lactobacillus-dominated communities . Relative abundance of lactic acid did not appear to correlate with relative abundance of individual Lactobacillus sp. in this limited sample , although lower levels of lactic acid were observed when L. gasseri was dominant , indicating differences in metabolic output of seemingly similar communities . Conclusions / Significance These findings benefit large-scale , field-based microbiome and metabolomic studies of the vaginal microbiota Background : Bacterial vaginosis ( BV ) recurs frequently after metronidazole treatment . This r and omized , single-masked clinical trial evaluated the efficacy of topical application of 62 % ethyl alcohol in emollient gel ( gel ) to the penis by male partners of women diagnosed with BV for preventing post-treatment BV recurrence . Methods : Among 587 Kenyan women presenting with vulvovaginal symptoms , 236 had BV ( vaginal Gram stain Nugent score ≥7 ) , of whom 223 ( 94.3 % ) agreed , along with their partners , to be r and omized : 115 to the intervention and 108 to the control arm . In the intervention arm , male partners agreed to apply gel each morning , and before and after sexual intercourse . All couples received counseling , condoms , and syndromic treatment of sexually transmitted infection symptoms . Follow-up visits were scheduled 1 week , 1 month , and 2 months postenrollment , with vaginal Gram stains at every visit and culture for H2O2-producing lactobacilli at the 2-month visit . The primary outcome was time to diagnosis of BV during follow-up . Results : In the primary intent-to-treat analysis , diagnosis of BV was significantly more frequent in the intervention arm ( hazard ratio : 1.44 , 95 % confidence interval : 1.01–2.04 ) . After adjustment for baseline covariates , the hazard ratio was 1.39 ( 95 % confidence interval : 0.98–1.99 ) . At the 2-month visit , prevalences of any vaginal lactobacilli or of H2O2-producing lactobacilli did not differ appreciably in the 2 study arms ( P = 0.81 and 0.32 , respectively ) . Conclusion : Daily use of the 62 % ethyl alcohol gel by men before and after sex significantly increased persistence or early recurrence of BV in their partners through 2 months after metronidazole treatment . However , no difference was observed in prevalences of vaginal lactobacilli within this same period Background To determine prevalence and incidence of bacterial vaginosis ( BV ) and risk factors in young sexually-active Australian women . Methods 10 
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When stratified by HC-type , combined-HC and POC were both associated with decreased prevalence of BV and risk of incident BV .
CONCLUSION HC-use was associated with a significantly reduced risk of BV .
This negative association was robust and present regardless of HC-type and evident across all three BV outcome measures .
When stratified by HC-type , combined-HC and POC were both individually associated with a reduction in the prevalence and incidence of BV .