***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: 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 Purpose The Manical and cohort was established to provide robust scientific data on HIV prevalence and incidence , patterns of sexual risk behaviour and the demographic impact of HIV in a sub-Saharan African population subject to a generalised HIV epidemic . The aims were later broadened to include provision of data on the coverage and effectiveness of national HIV control programmes including antiretroviral therapy ( ART ) . Participants General population open cohort located in 12 sites in Manical and , east Zimbabwe , representing 4 major socioeconomic strata ( small towns , agricultural estates , roadside settlements and subsistence farming areas ) . 9,109 of 11,453 ( 79.5 % ) eligible adults ( men 17 - 54 years ; women 15–44 years ) were recruited in a phased household census between July 1998 and January 2000 . Five rounds of follow-up of the prospect i ve household census and the open cohort were conducted at 2-year or 3-year intervals between July 2001 and November 2013 . Follow-up rates among surviving residents ranged between 77.0 % ( over 3 years ) and 96.4 % ( 2 years ) . Findings to date HIV prevalence was 25.1 % at baseline and had a substantial demographic impact with 10-fold higher mortality in HIV-infected adults than in uninfected adults and a reduction in the growth rate in the worst affected areas ( towns ) from 2.9 % to 1.0%pa . HIV infection rates have been highest in young adults with earlier commencement of sexual activity and in those with older sexual partners and larger numbers of lifetime partners . HIV prevalence has since fallen to 15.8 % and HIV incidence has also declined from 2.1 % ( 1998 - 2003 ) to 0.63 % ( 2009 - 2013 ) largely due to reduced sexual risk behaviour . HIV-associated mortality fell substantially after 2009 with increased availability of ART . Future plans We plan to extend the cohort to measure the effects on the epidemic of current and future HIV prevention and treatment programmes . Proposals for access to these data and for collaboration are welcome BACKGROUND Universal antiretroviral therapy ( ART ) , as per the 2015 WHO recommendations , might reduce  population HIV incidence . We investigated the effect of universal test and treat on HIV acquisition at population level in a high prevalence rural region of South Africa . METHODS We did a phase 4 , open-label , cluster r and omised trial of 22 communities in rural KwaZulu-Natal , South Africa . We included individuals residing in the communities who were aged 16 years or older . The clusters were composed of aggregated local areas ( neighbourhoods ) that had been identified in a previous study in the Hlabisa subdistrict . The study statisticians r and omly assigned clusters ( 1:1 ) with MapInfo Pro ( version 11.0 ) to either the control or intervention communities , stratified on the basis of antenatal HIV prevalence . We offered  residents repeated rapid HIV testing during home-based visits every 6 months for about 4 years in four clusters , 3 years in six clusters , and 2 years in 12 clusters ( 58 cluster-years ) and referred HIV-positive participants to trial clinics for ART ( fixed-dose combination of tenofovir , emtricitabine , and efavirenz ) regardless of CD4 cell count ( intervention ) or according to national guidelines ( initially ≤350 cells per μL and < 500 cells per μL from January , 2015 ; control ) . Participants and investigators were not masked to treatment allocation . We used dried blood spots once every 6 months provided by participants who were HIV negative at baseline to estimate the primary outcome of HIV incidence with cluster-adjusted Poisson generalised estimated equations in the intention-to-treat population after 58 cluster-years of follow-up . This study is registered with Clinical Trials.gov , number NCT01509508 , and the South African National Clinical Trials Register , number DOH-27 - 0512 - 3974 . FINDINGS Between March 9 , 2012 , and June 30 , 2016 , we contacted 26 518 ( 93 % ) of 28 419 eligible individuals . Of 17 808 ( 67 % ) individuals with a first negative dried blood spot test , 14 223 ( 80 % ) had subsequent dried blood spot tests , of whom 503 seroconverted after follow-up of 22 891 person-years . Estimated HIV incidence was 2·11 per 100 person-years ( 95 % CI 1·84 - 2·39 ) in the intervention group and 2·27 per 100 person-years ( 2·00 - 2·54 ) in the control group ( adjusted hazard ratio 1·01 , 95 % CI 0·87 - 1·17 ; p=0·89 ) . We documented one case of suicidal attempt in a woman following HIV seroconversion . 128 patients on ART had 189 life-threatening or grade 4 clinical events : 69 ( 4 % ) of 1652 in the control group and 59 ( 4 % ) of 1367 in the intervention group ( p=0·83 ) . INTERPRETATION The absence of a lowering of HIV incidence in universal test and treat clusters most likely result ed from poor linkage to care . Policy change to HIV universal test and treat without innovation to improve health access is unlikely to reduce HIV incidence . FUNDING ANRS , GiZ , and 3ie BACKGROUND Preexposure prophylaxis with antiretroviral drugs has been effective in the prevention of  human immunodeficiency virus ( HIV ) infection  in some trials but not in others . METHODS In this r and omized , double-blind , placebo-controlled trial , we assigned 2120 HIV-negative women in Kenya , South Africa , and Tanzania to receive either a combination of tenofovir disoproxil fumarate and emtricitabine ( TDF-FTC ) or placebo once daily . The primary objective was to assess the effectiveness of TDF-FTC  in preventing HIV acquisition and to evaluate safety . RESULTS HIV infections occurred in 33 women in the TDF-FTC group ( incidence rate , 4.7 per 100 person-years ) and in 35 in the placebo group ( incidence rate , 5.0 per 100 person-years ) , for an estimated hazard ratio in the TDF-FTC group of 0.94 ( 95 % confidence interval , 0.59 to 1.52 ; P=0.81 ) . The proportions of women with nausea , vomiting , or elevated alanine aminotransferase levels were significantly higher in the TDF-FTC group ( P=0.04 , P<0.001 , and P=0.03 , respectively ) . Rates of drug discontinuation because of hepatic or renal abnormalities were higher in the TDF-FTC group ( 4.7 % ) than in the placebo group ( 3.0 % , P=0.051 ) . Less than 40 % of the HIV-uninfected women in the TDF-FTC group had evidence of recent pill use at visits that were matched to the HIV-infection window for women with seroconversion . The study was stopped early , on April 18 , 2011 , because of lack of efficacy . CONCLUSIONS Prophylaxis with TDF-FTC did not significantly reduce the rate of HIV infection and was associated with increased rates of side effects , as compared with placebo . Despite substantial counseling efforts , drug adherence appeared to be low . ( Supported by the U.S. Agency for International Development and others ; FEM-PrEP Clinical Trials.gov number , NCT00625404 . ) Introduction Prevention of acute HIV infections in pregnancy is required to achieve elimination of pediatric HIV . Identification and support for HIV negative pregnant women and their partners , particularly serodiscordant couples , are critical . A mixed method study done in Southern Mozambique estimated HIV incidence during pregnancy , associated risk factors and factors influencing partner 's HIV testing . Methods Between April 2008 and November 2011 , a prospect i ve cohort of 1230 HIV negative pregnant women was followed during pregnancy . A structured question naire , HIV testing , and collection of dried blood spots were done at 2–3 scheduled visits . HIV incidence rates were calculated by repeat HIV testing and risk factors assessed by Poisson regression . A qualitative study including 37 individual interviews with men , women , and nurses and 11 focus group discussion s ( n = 94 ) with men , women and gr and mothers explored motivators and barriers to uptake of male HIV testing . Results HIV incidence rate was estimated at 4.28/100 women-years ( 95%CI : 2.33–7.16 ) . Significant risk factors for HIV acquisition were early sexual debut ( RR 3.79 , 95%CI : 1.04–13.78 , p = 0.04 ) and living in Maputo Province ( RR 4.35 , 95%CI : 0.97–19.45 , p = 0.05 ) . Nineteen percent of women reported that their partner had tested for HIV ( 93 % knew the result with 8/213 indicating an HIV positive partner ) , 56 % said their partner had not tested and 19 % did not know their partner test status . Of the 14 seroconversions , only one reported being in a serodiscordant relationship . Fear of discrimination or stigma was reported as a key barrier to male HIV testing , while knowing the importance of getting tested and receiving care was the main motivator . Conclusions HIV incidence during pregnancy is high in Southern Mozambique , but knowledge of partners ' HIV status remains low . Knowledge of both partners ' HIV status is critical for maximal effectiveness of prevention and treatment services to reach elimination of pediatric HIV/AIDS Background The study aim ed to assess the feasibility of conducting large scale HIV prevention clinical trials in Mozambique by measuring HIV prevalence and incidence among women of reproductive age . This paper describes the baseline socio-demographic characteristics of the Mozambique Microbicides Development Programme ( MDP 
    Output:
    
Incidence often peaked earlier ( during teenage years ) among high-risk groups compared with general population s. Since 2005 , HIV incidence among adolescent girls and young women  declined in Rakai ( Ug and a ) and Manical and ( Zimbabwe ) , and also declined among female sex workers in Kenya , but not in the highest-risk communities in South Africa and Ug and a. INTERPRETATION Few sources of direct estimates of HIV incidence exist in high-burden countries and trend analyses with disaggregated data for age and sex are rare but indicate recent declines among adolescent girls and young women .
In some of the highest-risk setting s , however , little evidence exists to suggest ART availability and other efforts slowed transmission by 2016 .
Despite wide geographical diversity in absolute levels of incidence in adolescent girls and young women , risk relative to males persisted in all setting s , with the greatest sex differentials in the youngest age groups .