***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*** 
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    Input: BACKGROUND Female-initiated HIV-prevention options , such as microbicides , are urgently needed . We assessed Carraguard , a carrageenan-based compound developed by the Population Council , for its efficacy and long-term safety in prevention of HIV infection in women . METHODS We undertook a r and omised , placebo-controlled , double-blind trial in three South African sites in sexually-active , HIV-negative women , aged 16 years and older . 6202 participants , who were r and omly assigned by a block r and omisation scheme to Carraguard ( n=3103 ) or placebo ( methylcellulose [ n=3099 ] ) , were instructed to use one applicator of gel plus a condom during each vaginal sex act . Participants were followed up for up to 2 years . Visits every 3 months included testing for HIV presence and pregnancy , pelvic examinations , risk reduction counselling , and treatment for curable sexually transmitted infections and symptomatic vaginal infections . The primary outcome was time to HIV seroconversion . Analysis was in the efficacy population ( a subset of the intention-to-treat population , excluding participants for whom efficacy could not be assessed ) . This study is registered with Clinical Trials.gov , number NCT00213083 . FINDINGS For the primary outcome ( time to HIV seroconversion ) we analysed 3011 women in the Carraguard group and 2994 in the placebo group .  HIV incidence was 3.3 per 100 woman-years ( 95 % CI 2.8 - 3.9 ) in the Carraguard group ( 134 events ) and 3.8 per 100 woman-years ( 95 % CI 3.2 - 4.4 ) in the placebo group ( 151 events ) , with no significant difference in the distribution of time to seroconversion ( p=0.30 ) . The covariate-adjusted hazard ratio was 0.87 ( 95 % CI 0.69 - 1.09 ) . Rates of self-reported gel use ( 96.2 % Carraguard , 95.9 % placebo ) and condom use ( 64.1 % in both groups ) at last sex acts were similar in both groups . On the basis of applicator testing , however , gel was estimated to have been used in only 42.1 % of sex acts , on average ( 41.1 % Carraguard , 43.1 % placebo ) . 1420 ( 23 % ) women in the intention-to-treat population had adverse events ( 713 Carraguard , 707 placebo ) , and 95 ( 2 % ) women had adverse events that were related to gel use ( 48 Carraguard , 47 placebo ) . Serious adverse events occurred in 72 ( 2 % ) women in the Carraguard group and 78 ( 3 % ) in the placebo group , only one of which was considered possibly related to gel use ( placebo group ) . INTERPRETATION This study did not show Carraguard 's efficacy in prevention of vaginal transmission of HIV . No safety concerns were recorded Introduction Since female learners in high schools in Cameroon fall within the age group hardest hit by HIV/AIDS , it is assumed that these learners might be exposed to sexual risk behaviours . However , little has been explored on the sexual risk behaviours of high school female learners in Cameroon . This study aim ed at examining the sexual risk behaviours of high school female learners in Mbonge subdivision of rural Cameroon . Methods A cross sectional design was adopted , using a self-administered question naire for data collection . Respondents were selected through disproportional stratified simple r and om sampling result ing in 210 female grade 10 to grade 12 learners from three participating high schools in Mbonge subdivision , Cameroon . Descriptive and inferential statistics were calculated using SPSS version 20 software program . Results Majority of the respondents , 54.0 % reported being sexually active , of whom only 39.8 % used condoms during first sex ; 49.5 % used condoms during last sex and 29.6 % used condoms consistently . Up to 32 % of the sexually active respondents had multiple sexual partners in the past one year before the study , while 9.3 % had multiple sexual partners during the study period . The mean age of first sex was 15.6 years . Lack of parental control , religion , academic profile , poverty , place of residence and perception of risk of HIV infection were the main factors significantly associated with sexual risk behaviours . Conclusion The findings indicate that sexual risk behaviours exist among high school female learners in Mbonge , Cameroon . There is need for campaigns and interventions to bring about sexual behaviour change BACKGROUND Underst and ing the signification of the word ' sex ' has implication s for both medical research and clinical practice . Little is known about how people of varying ages define sex and how situational qualifiers influence definitions across age groups . To our knowledge , this is the first study of a representative sample to assess attitudes about which sexual behaviours constitute having ' had sex ' and to examine possible mediating factors ( gender , age , giving/receiving stimulation , male ejaculation , female orgasm , condom use or brevity ) . METHODS A telephone survey  of English-speaking residents of Indiana ( USA ) using r and om-digit-dialling produced a final sample of 204 men and 282 women ( n = 486 ) ranging in age from 18 to 96 years . Questions assessed the respondents ' attitudes on  manual-genital ( MG ) , oral-genital ( OG ) , penile-vaginal intercourse ( PVI ) and penile-anal intercourse ( PAI ) behaviours . RESULTS There was no universal consensus on which behaviours constituted having ' had sex ' . More than 90 % responded ' yes ' to PVI but one in five responded ' no ' to PAI , three in 10 responded ' no ' to OG and about half endorsed MG . Fewer endorsed PVI with no male ejaculation ( 89.1 % ) compared with PVI without a qualifier ( 94.8 % , P < 0.001 ) . MG was endorsed more often when received ( 48.1 % ) than given ( 44.9 % , P < 0.001 ) . Among men , the oldest and youngest age groups were significantly less likely to believe certain behaviours constituted having ' had sex ' . CONCLUSIONS These findings highlight the need to use behaviour-specific terminology in sexual history taking , sex research , sexual health promotion and sex education . Research ers , educators and medical practitioners should exercise caution and not assume that their own definitions of having ' had sex ' are shared by their research participants or patients Background HIV acquisition in pregnancy and breastfeeding contributes significantly toward pediatric HIV infection . However , little is known about how sexual behavior changes during pregnancy and postpartum periods which will help develop targeted HIV prevention and transmission interventions , including pre-exposure prophylaxis ( PrEP ) . Methods Cross-sectional study in HIV-infected and uninfected pregnant and postpartum women in Cape Town , South Africa .  Interviewers collected survey data on demographic , sexual behaviors , and alcohol use among pregnant and post-partum women . We report descriptive results of sexual behavior by trimester and postpartum period , and results of multivariable logistic regression stratified by pregnancy status . Results We enrolled 377 pregnant and postpartum women ( 56 % pregnant , 40 % HIV-infected ) . During pregnancy , 98 % of women reported vaginal sex ( 8 % anal sex , 44 % oral sex ) vs. 35 % and 88 % during the periods 0–6 and 7–12 months postpartum , respectively ( p<0.05 ) . More pregnant women reported having > 1 partner in the past 12-months compared to postpartum women ( 18 % vs. 13 % , respectively , p<0.05 ) . Sex frequency varied by trimester with greatest mean sex acts occurring during first trimester and > 6-months postpartum ( 13 mean sex acts in first trimester ; 17 mean sex acts > 6-months postpartum ) . Pregnant women had increased odds of reporting condomless sex at last sex ( aOR = 2.96;95%CI = 1.84–4.78 ) and ever having condomless sex in past 3-months ( aOR = 2.65;95%CI = 1.30–5.44 ) adjusting for age , HIV status , and sex frequency compared to postpartum women . Conclusion We identified that sexual behaviors and risk behaviors were high and changing during pregnancy and postpartum periods , presenting challenges to primary and secondary HIV prevention efforts , including PrEP delivery to pregnant and breastfeeding women Background Sex work has shifted from brothels to entertainment  establishments  ( EEs ) in Asia . Men who patronise EEs  could act as a bridging population for human immunodeficiency virus ( HIV ) and sexually transmitted infection ( STI ) transmission through unprotected sex with the female EE workers to their spouses and regular partners . The aim of this study was to compare the prevalence and factors associated with risky sexual behaviours among the heterosexual men who patronised the EEs and brothels in Singapore . Methods This was a cross-sectional survey involving 569 heterosexual men ( 297 recruited from brothels and 272 from EEs ) . A 2-stage sampling involving proportional stratified r and om sampling of the brothels and EEs , followed by time location sampling of the men , was conducted . For multivariable analysis , we used a mixed effects logistic model with backward elimination to account for clustering by venue and to obtain the adjusted odds ratio ( aOR ) for the association of various factors with consistent condom use in vaginal and oral sex respectively . Results Men who patronised EEs were younger , more likely to be single , more highly-educated and comprised more professionals compared to the brothel group . On multivariable analysis , consistent condom use for vaginal sex decreased at the EE setting ( aOR 0.64 ; 95 % CI : 0.42 –0.97 ) and with alcohol use before sex ( aOR 0.67 ; 95 % CI : 0.46 – 0.98 ) and increased with perceived high risk of getting HIV/STIs from partner ( aOR 2.08 ; 95 % CI : 1.30 – 3.32 ) and partner ’s request for condom use ( aOR 5.48 ; 95 % CI : 1.20 – 25.11 ) . For consistent condom use with oral sex , this decreased at the EE setting ( aOR 0.64 ; 95 % CI : 0.39 – 0.98 ) and with alcohol use before sex ( aOR 0.50 ; 95 % CI : 0.31 – 0.81 ) and increased with partner ’s request for condom use ( aOR 5.19 ; 95 % CI : 1.38 – 19.57 ) . Conclusions Men who patronised EEs  practised risker sexual behaviours compared to the brothel group . Priority should be given for intervention programmes to target men who patronise EEs , which could involve the female EE workers , the EE owners as well as the managers for effective HIV/STI prevention Vaginal Gel Versus HIV HIV prevention technologies for women are urgently needed , especially in sub-Saharan Africa where young women bear the greatest burden of the HIV epidemic . Abdool Karim et al. ( p. 1168 ; published online 19 July ) present the results of the CAPRISA 004 r and omized control trial . The nearly 3-year-long trial , conducted in urban and rural South African women , tested the efficacy of a vaginal gel containing the antiretroviral drug tenofovir in preventing HIV infection . The dosing strategy required application of the gel both before and after coitus , and with this regime HIV infection was reduced by approximately 39 % overall , by 54 % in women with high adherence to the protocol , and with no increase in overall adverse event rates . Tenofovir in a vaginal gel formulation shows significant protection against HIV infection in a r and omized control trial . The Centre for the AIDS Program of Research in South Africa ( CAPRISA ) 004 trial assessed the effectiveness and safety of a 1 % vaginal gel formulation of tenofovir , a nucleotide reverse transcriptase inhibitor , for the prevention of HIV acquisition in women . A double-blind , r and omized controlled trial was conducted comparing  tenofovir gel ( n = 445 women ) with  placebo gel ( n = 444 women ) in sexually active , HIV-uninfected 18- to 40-year-old women in urban and rural KwaZulu-Natal , South Africa .  HIV serostatus , safety , sexual behavior , and gel and condom use were assessed at monthly follow-up visits for 30 months . HIV incidence in the tenofovir gel arm was 5.6 per 100 women-years ( person time of study observation ) ( 38 out of 680.6 women-years ) compared with 9.1 per 100 women-years ( 60 out of 660.7 women-years ) in the placebo gel arm ( incidence rate ratio = 0.61 ; P = 0.017 ) . In high adherers ( gel adherence > 80 % ) , HIV incidence was 54 % lower ( P = 0.025 ) in the tenofovir gel arm . In intermediate adherers ( gel adherence 50 to 80 % ) and 
    Output:
    
Higher prevalences of oral and anal sex were reported among population s at high-risk for sexually transmitted infections and HIV and university students and , in most studies , both behaviours were more commonly reported by males than females .
Heterosexual oral and anal sexual acts were associated with some high-risk behaviours such as inconsistent condom use and multiple sexual partners .
Conclusion Reported oral and anal sex between men and women are prevalent behaviours in sub-Saharan Africa .