***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 The International Maternal Pediatric Adolescent AIDS Clinical Trials Network ( IMPAACT ) P1060 study demonstrated short-term superiority of lopinavir/ritonavir ( LPV/r ) over nevirapine ( NVP ) in antiretroviral therapy ( ART ) , regardless of prior NVP exposure . However , NVP-based ART had a marginal benefit in CD4 percentage ( CD4 % ) and growth . We compared 5-year outcomes from this clinical trial . METHODS Human immunodeficiency virus (HIV)-infected , ART-eligible children were enrolled into 2 cohorts based on prior NVP exposure and r and omized to NVP- or LPV/r-based ART .  The data safety monitoring board recommended unblinding results in both cohorts due to superiority of LPV/r for the primary endpoint : stopping r and omized treatment , virologic failure ( VF ) , or death by 6 months . Participants were offered a switch in regimens ( if on NVP ) and continued observational follow-up . We compared time to VF or death , death , and CD4 % and growth changes using intention-to-treat analyses . Additionally , inverse probability weights were used to account for treatment switching and censoring . RESULTS As of September 2014 , 329 of the 451 ( 73 % ) enrolled participants were still in follow-up ( median , 5.3 years ; interquartile range [ IQR ] , 4.3 - 6.4 ) , with 52 % on NVP and 88 % on LPV/r as originally r and omized . NVP arm participants had significantly higher risk of VF or death ( adjusted hazard ratio [ aHR ] , 1.90 ; 95 % confidence interval [ CI ] , 1.37 - 2.65 ) but not death alone ( aHR , 1.65 ; 95 % CI , .72 - 3.76 ) compared with participants r and omized to LPV/r . Mean CD4 % was significantly higher in the NVP arm up to 1 year after ART initiation , but not beyond . Mean weight-for-age z scores were marginally higher in the NVP arm , but height-for-age z scores did not differ . Similar trends were observed in sensitivity analyses . CONCLUSIONS These findings support the current World Health Organization recommendation of LPV/r in first-line ART regimens for HIV-infected children . CLINICAL TRIALS REGISTRATION NCT00307151 Objectives : To evaluate the effect of hormonal contraception including combined oral contraceptives ( COCs ) , and the injectable progestins depo-medroxyprogesterone acetate ( DMPA ) and norethisterone enanthate ( Net-En ) on the  risk of HIV acquisition among women in South Africa . Design / methods : We analyzed data from 5567 women aged 16–49 years participating in the Carraguard Phase 3 Efficacy Trial . Participants were interviewed about contraceptive use and sexual behaviors and underwent pelvic examinations and HIV testing quarterly . We used marginal structural Cox regression models to estimate the effect of hormonal contraception exposure on HIV acquisition risk among women overall and among young women ( 16–24 years ) in particular . Results : Two hundred and seventy participants became HIV-infected ( 3.7 per 100 woman-years ) ; HIV incidence was 2.8 , 4.6 , 3.5 and 3.4 per 100 woman-years in the COC , DMPA , Net-En and nonhormonal contraceptive groups , respectively ( P = 0.09 ) . The adjusted hazard ratios ( AHRs ) were 0.84 [ 95 % confidence interval ( CI ) 0.51–1.39 ] , 1.28 ( 95 % CI 0.92–1.78 ) and 0.92 ( 95 % CI 0.64–1.32 ) among COC , DMPA and Net-En users , respectively , compared with the nonhormonal group controlling for covariates . Age modified the effect of hormonal contraception on HIV acquisition risk ; among young women , the AHRs were 1.02 ( 95 % CI 0.46–2.28 ) for COCs , 1.68 ( 95 % CI 0.96–2.94 ) for DMPA and 1.36 ( 95 % CI0.78–2.35 ) for Net-En users . Conclusions : In this study conducted among South African women , hormonal contraception did not significantly increase the risk of HIV acquisition . However , the effect estimate does not rule out a moderate increase in HIV risk associated with DMPA use found in some other recent studies Background Little is known about safety of and adherence to intermittent HIV PrEP regimens , which may be more feasible than daily dosing in some setting s. We present safety and adherence data from the first trial of an intermittent PrEP regimen among Kenyan men who have sex with men ( MSM ) and female sex workers ( FSW ) . Methods /Principal Findings MSM and FSW were r and omized to daily oral FTC/TDF or placebo , or intermittent ( Monday , Friday and within 2 hours after sex , not to exceed one dose per day ) oral FTC/TDF or placebo in a 2∶1∶2∶1 ratio ; volunteers were followed monthly for 4 months . Adherence was assessed with the medication event monitoring system ( MEMS ) . Sexual activity data were collected via daily text message ( SMS ) queries and timeline followback interviews with a one-month recall period . Sixty-seven men and 5 women were r and omized into the study .  Safety was similar among all groups . Median MEMS adherence rates were 83 % [ IQR : 63–92 ] for daily dosing and 55 % [ IQR:28–78 ] for fixed intermittent dosing ( p = 0.003 ) , while adherence to any post-coital doses was 26 % [ IQR:14–50 ] . SMS response rates were low , which may have impaired measurement of post-coital dosing adherence . Acceptability of PrEP was high , regardless of dosing regimen . Conclusions / Significance Adherence to intermittent dosing regimens , fixed doses , and in particular coitally-dependent doses , may be more difficult than adherence to daily dosing . However , intermittent dosing may still be appropriate for PrEP if intracellular drug levels , which correlate with prevention of HIV acquisition , can be attained with less than daily dosing and if barriers to adherence can be addressed . Additional drug level data , qualitative data on adherence barriers , and better methods to measure sexual activity are necessary to determine whether adherence to post-coital PrEP could be comparable to more st and ard regimens . Trial Registration Clinical Trials.gov BACKGROUND The ability of specific behaviour-change interventions to reduce HIV infection in young people remains question able . Since January 1999 , an adolescent sexual and reproductive health ( SRH ) intervention has been implemented in ten r and omly chosen intervention communities in rural Tanzania , within a community r and omised trial ( see below ; NCT00248469 ) . The intervention consisted of teacher-led , peer-assisted in-school education , youth-friendly health services , community activities , and youth condom promotion and distribution . Process evaluation in 1999 - 2002 showed high intervention quality and coverage . A 2001/2 intervention impact evaluation showed no impact on the primary outcomes of HIV seroincidence and herpes simplex virus type 2 ( HSV-2 ) seroprevalence but found substantial improvements in SRH knowledge , reported attitudes , and some reported sexual behaviours . It was postulated that the impact on " upstream " knowledge , attitude , and reported behaviour outcomes seen at the 3-year follow-up would , in the longer term , lead to a reduction in HIV and HSV-2 infection rates and other biological outcomes . A further impact evaluation survey in 2007/8 ( approximately 9 years post-intervention ) tested this hypothesis . METHODS AND FINDINGS This is a cross-sectional survey ( June 2007 through July 2008 ) of 13,814 young people aged 15 - 30 y who had attended trial schools during the first phase of the MEMA kwa Vijana intervention trial ( 1999 - 2002 ) . Prevalences of the primary outcomes HIV and HSV-2 were 1.8 % and 25.9 % in males and 4.0 % and 41.4 % in females , respectively . The intervention did not significantly reduce risk of HIV ( males adjusted prevalence ratio [ aPR ] 0.91 , 95%CI 0.50 - 1.65 ; females aPR 1.07 , 95%CI 0.68 - 1.67 ) or HSV-2 ( males aPR 0.94 , 95%CI 0.77 - 1.15 ; females aPR 0.96 , 95%CI 0.87 - 1.06 ) . The intervention was associated with a reduction in the proportion of males reporting more than four sexual partners in their lifetime ( aPR 0.87 , 95%CI 0.78 - 0.97 ) and an increase in reported condom use at last sex with a non-regular partner among females ( aPR 1.34 , 95%CI 1.07 - 1.69 ) . There was a clear and consistent beneficial impact on knowledge , but no significant impact on reported attitudes to sexual risk , reported pregnancies , or other reported sexual behaviours . The study population was likely to have been , on average , at lower risk of HIV and other sexually transmitted infections compared to other rural population s , as only youth who had reached year five of primary school were eligible . CONCLUSIONS SRH knowledge can be improved and retained long-term , but this intervention had only a limited effect on reported behaviour and no significant effect on HIV/STI prevalence .  Youth interventions integrated within intensive , community-wide risk reduction programmes may be more successful and should be evaluated . TRIAL REGISTRATION Clinical Trials.gov BACKGROUND Male circumcision could provide substantial protection against acquisition of HIV-1 infection . Our aim was to determine whether male circumcision had a protective effect against HIV infection , and to assess safety and changes in sexual behaviour related to this intervention . METHODS We did a r and omised controlled trial of 2784 men aged 18 - 24 years in Kisumu , Kenya . Men were r and omly assigned to an intervention group ( circumcision ; n=1391 ) or a control group ( delayed circumcision , 1393 ) , and assessed by  HIV testing , medical examinations , and behavioural interviews during follow-ups at 1 , 3 , 6 , 12 , 18 , and 24 months . HIV seroincidence was estimated in an intention-to-treat analysis . This trial is registered with Clinical Trials.gov , with the number NCT00059371 . FINDINGS The trial was stopped early on December 12 , 2006 , after a third interim analysis review ed by the data and safety monitoring board . The median length of follow-up was 24 months . Follow-up for HIV status was incomplete for 240 ( 8.6 % ) participants . 22 men in the intervention group and 47 in the control group had tested positive for HIV when the study was stopped . The 2-year HIV incidence was 2.1 % ( 95 % CI 1.2 - 3.0 ) in the circumcision group and 4.2 % ( 3.0 - 5.4 ) in the control group ( p=0.0065 ) ; the relative risk of HIV infection in circumcised men was 0.47 ( 0.28 - 0.78 ) , which corresponds to a reduction in the risk of acquiring an HIV infection of 53 % ( 22 - 72 ) . Adjusting for non-adherence to treatment and excluding four men found to be seropositive at enrollment , the protective effect of circumcision was 60 % ( 32 - 77 ) . Adverse events related to the intervention ( 21 events in 1.5 % of those circumcised ) resolved quickly . No behavioural risk compensation after circumcision was observed . INTERPRETATION Male circumcision significantly reduces the risk of HIV acquisition in young men in Africa . Where appropriate , voluntary , safe , and affordable circumcision services should be integrated with other HIV preventive interventions and provided as expeditiously as possible The aim of this study is to assess whether the Government of Kenya 's Cash Transfer for Orphans and Vulnerable Children ( Kenya CT-OVC ) can reduce the risk of HIV among young people by postponing sexual debut . The program provides an unconditional transfer of US$ 20 per month directly to the main caregiver in the household . An evaluation of the program was implemented in 2007–2009 in seven districts . Fourteen Locations were r and omly assigned to receive the program and fourteen were assigned to a control arm . A sample of households was enrolled in the evaluation in 2007 . We revisited these households in 2011 and collected information on sexual activity among individuals between 15–25 years of age . We used logistic regression , adjusted for the respondent 's age , sex and relationship to caregiver , the age , sex and schooling of the caregiver and whether or not the household lived in Nairobi at baseline , to compare rates of sexual debut among young people living in program households with those living in control households who had not yet entered the program . Our results , adjusted for these covariates , show that the program reduced the odds of sexual debut by 31 percent . There were no statist 
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Conclusions The literature review , focus groups , and modeling indicate that offering age- and gender- specific combination HIV prevention interventions that include biomedical , behavioral , and structural interventions can have an impact on HIV risk reduction .
Implementing this protocol will show the feasibility of delivering these services at scale .