***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 The purpose of this study was to test the effects of an  education program in Tanzania  design ed to reduce children 's risk of human immunodeficiency virus ( HIV ) infection and to improve their tolerance of and care for people with acquired immunodeficiency syndrome ( AIDS ) . METHODS A r and omized controlled community trial including baseline and 12-month follow-up surveys was employed . Public primary schools in the Arusha and Kilimanjaro regions of Tanzania were stratified according to location and r and omly assigned to intervention ( n = 6 ) or comparison ( n = 12 ) conditions . Of the 1063 sixth- grade students ( average age : 13.6 years ) who participated at baseline , 814 participated in the follow-up survey . RESULTS At follow-up , statistically significant effects favoring the intervention group were observed for exposure to AIDS information and communication , AIDS knowledge , attitudes toward people with AIDS , and subjective norms and behavioral intentions toward having sexual intercourse . A consistent positive but nonsignificant trend was seen for attitudes toward having sexual intercourse and for initiation of sexual intercourse during the previous year ( 7 % vs 17 % ) . CONCLUSIONS It is feasible and effective to train local teachers and health workers to provide HIV/AIDS education to Tanzanian primary school children Background Worldwide , about 50 % of all new cases of HIV occur in youth between age 15 and 24 years . Studies in various sub-Saharan African countries show that both out of school and in school adolescents and youth are engaged in risky sexual behaviors . School-based health education has been a cornerstone of youth-focused HIV prevention efforts since the early 1990s . In addition , peer-based interventions have become a common method to effect important health-related behavior changes and address the HIV/AIDS p and emic . Thus , the aim of this study was to evaluate efficacy of peer education on changing HIV related risky sexual behaviors among school youth in Addis Ababa , Ethiopia . Methods A quasi experimental study with peer education intervention was conducted in purposively selected four secondary schools ( two secondary schools for the intervention and other two for the control group ) in Addis Ababa , Ethiopia . Five hundred sixty students from r and omly selected sections of grade 11 were assessed through anonymous question naires conducted in pre- and post-intervention periods . Pertinent data on socio-demographic and sexual behavior related factors were collected . The statistical packages used for data entry and analysis were epi-info version 3.5.4 and SPSS version 20.0 respectively . Chi-square test and multivariable logistic regressions were used for testing association between peer education intervention and sexual behaviors of students . In addition to testing association between dependent and independent variables , multi-variable analysis was employed to control for the effects of confounding variables . Results When the pre and post intervention data of each group were compared , comprehensive Knowledge of HIV ( P-Values = 0.004 ) and willingness to go for HIV counseling and testing ( P-value = 0.01 ) showed significant differences among intervention group students during post intervention period . Moreover , students in the intervention group were more likely to use condoms during post intervention period compared to students of the control group [ AOR = 4.73 ( 95 % CI ( 1.40–16.0 ) ] . Conclusion Despite short follow up period , students in the intervention group demonstrated positive changes in HIV related comprehensive knowledge and showed better interest to go for HIV testing in the near future . Furthermore , positive changes on risky sexual behaviors were reported from the intervention group . Implementing secondary school targeted peer education by allocating appropriate amounts of re sources ( money , man power , material s and time ) could play significant role to prevent and control HIV/AIDS among school youth 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 PURPOSE To evaluate an intervention ( based on one which had previously been successful in reducing adolescent human immunodeficiency virus ( HIV ) risk behaviors in the United States ) among adolescents residing in Namibia , a country located in sub-Saharan Africa . METHODS A r and omized trial of a 14-session face-to-face intervention emphasizing abstinence and safer sex was conducted among 515 youth ( median age 17 years ; median grade 11 ) attending 10 secondary schools located in two districts in Namibia .  Knowledge , attitudes , intentions , and HIV risk behaviors were assessed at baseline and in the immediate postintervention period . RESULTS Knowledge increased significantly among intervention compared to control youth ( 88 % vs. 82 % ; correct responses , p < .0001 ) . At postintervention follow-up , more intervention than control youth believed that they could be intimate without having sex , could have a girlfriend or boyfriend for a long time without having sex , could explain the process of impregnation , knew how to use a condom , and could ask for condoms in a clinic . Fewer intervention than control youth believed that if a girl refused to have sex with her boyfriend it was permissible for him to strike her , and that condoms took away a boy 's pleasure . More intervention than control youth anticipated using a condom when they did have sex , and fewer expected to drink alcohol . Finally , after intervention , there was a trend for increased condom use . There were significant gender-related differences at baseline , although intervention impact was generally equivalent . CONCLUSIONS These findings provide support for the judicious adaptation of successful Western HIV prevention programs in other cultural setting s. A single intervention approach appears to be effective in short-term follow-up with both genders Abstract Objective To assess effects on condom use and other sexual behaviour of an HIV prevention programme at school that promotes the use of condoms with and without emergency contraception . Design Cluster r and omised controlled trial . Setting 40 public high schools in the state of Morelos , Mexico . Participants 10 954 first year high school students . Intervention Schools were r and omised to one of three arms : an HIV prevention course that promoted condom use , the same course with emergency contraception as back-up , or the existing sex education course . Self administered anonymous question naires were completed at baseline , four months , and 16 months . Students at intervention schools received a 30 hour course ( over 15 weeks ) on HIV prevention and life skills , design ed in accordance with guidelines of the joint United Nations programme on HIV/AIDS . Two extra hours of education on emergency contraception were given to students in the condom promotion with contraception arm . Main outcome measures Primary outcome measure was reported condom use . Other outcomes were reported sexual activity ; knowledge and attitudes about HIV and emergency contraception ; and attitudes and confidence about condom use . Results Intervention did not affect reported condom use . Knowledge of HIV improved in both intervention arms and knowledge of emergency contraception improved in the condom promotion with contraception arm . Reported sexual behaviour was similar in the intervention arms and the control group . Conclusion A rigorously design ed , implemented , and evaluated HIV education course based in public high schools did not reduce risk behaviour , so such courses need to be re design ed and evaluated . Addition of emergency contraception did not decrease reported condom use or increase risky sexual behaviour but did increase reported use of emergency contraception This study investigated whether there were any changes in knowledge and normative beliefs regarding abstinence and condoms and personal risk perception of acquiring HIV among Zambian secondary -school students who were exposed to a peer sexual health intervention .  Schools were r and omly assigned to intervention and control groups . A baseline assessment that measured knowledge , normative beliefs about abstinence and condoms and personal risk perception was conducted in all schools . Students in the intervention group were exposed for a 1-hour- and -45-minute-long in-class peer sexual health intervention . Students in the control schools were exposed to a 1-hour-long in-class peer water purification intervention . A follow-up assessment of students was conducted after the intervention . Logistic regression analyses were conducted to determine whether significant differences between intervention and control groups emerged at follow-up . Relative to students in the control group , knowledge was higher and normative beliefs about abstinence and condoms were significantly more positive among students in the intervention schools . Students in the intervention schools also had a higher personal risk perception of acquiring HIV than students in control schools . These findings show that a school-based peer sexual health intervention implemented in Zambia was effective in increasing knowledge , positive normative beliefs about abstinence and condoms , and personal risk perception PURPOSE To evaluate the efficacy of an abstinence-centered sex education program in adolescent pregnancy prevention , the TeenSTAR Program was applied in a high school in Santiago , Chile . METHODS A total of 1259 girls from a Santiago high school were divided into three cohorts depending on the year they started high school : the 1996 cohort of 425 students , which received no intervention ; the 1997 cohort , in which 210 students received an intervention  and 213  ( control group ) did not  ; and the 1998 cohort , in which 328 students received an intervention  and 83 ( control group ) did not .  Students were r and omly assigned to control and intervention groups in these cohorts , before starting with the program . We conducted a prospect i ve , r and omized study using the application of the TeenSTAR sex education program during the first year of high school to the intervention groups in the 1997 and 1998 cohorts . All cohorts were followed up for 4 years ; pregnancy rates were recorded and subsequently contrasted in the intervention and control groups . Pregnancy rates were measured and Risk Ratio with 95 % confidence interval were calculated for intervention and control groups in each cohort . RESULTS Pregnancy rates for the intervention and control groups in the 1997 cohort were 3.3 % and 18.9 % , respectively ( RR : 0.176 , CI : 0.076 - 0.408 ) . Pregnancy rates for the intervention and control groups in the 1998 cohort were 4.4 % and 22.6 % , respectively ( RR 0.195 , CI : 0.099 - 0.384 ) . CONCLUSIONS The abstinence-centered TeenSTAR sex education intervention was effective in the prevention of unintended adolescent pregnancy Background : HIV prevention among young people in southern Africa is a public health priority . There is little rigorous evidence of the effectiveness of different intervention approaches . We describe findings of a cluster r and omized trial of a community-based , multicomponent HIV , and reproductive health intervention aim ed at changing social norms for adolescents in rural Zimbabwe . Methods : Thirty rural communities were r and omized to early or deferred implementation of the intervention in 2003 . Impact was assessed in a representative survey of 
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RESULTS The review has identified the large gap between the current state of the art and the ultimate goal of the education-based approaches contributing to the reduction of HIV incidence rates .
Significant positive impact has been reported mainly on mediating factors to behavioural change ( knowledge , attitude , and intentions ) .
The reported impact on actual behaviour change has been weak and short-lived .
There is only very modest evidence of the effectiveness of educational interventions as a result of several gaps in project design , implementation and follow-up .