***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 
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    Input: Objective To evaluate the effectiveness of register based , yearly chlamydia screening . Design Controlled trial with r and omised stepped wedge implementation in three blocks . Setting Three regions of the Netherl and s : Amsterdam , Rotterdam , and South Limburg . Participants 317 304 women and men aged 16 - 29 years listed on municipal registers at start of trial . Intervention From March 2008 to February 2011 , the Chlamydia Screening Implementation programme offered yearly chlamydia screening tests . Postal invitations asked people to use an internet site to request a kit for self collection of sample s , which would then be sent to regional laboratories for testing . Treatment and partner notification were done by the general practitioner or at a sexually transmitted infection clinic . Main outcome measures Primary outcomes were the percentage of chlamydia tests positive ( positivity ) , percentage of invitees returning a specimen ( uptake ) , and estimated chlamydia prevalence . Secondary outcomes were positivity according to sex , age , region , and sociodemographic factors ; adherence to screening invitations ; and incidence of self reported pelvic inflammatory disease . Results The participation rate was 16.1 % ( 43 358/269 273 ) after the first invitation , 10.8 % after the second , and 9.5 % after the third , compared with 13.0 % ( 6223/48 031 ) in the control block invited at the end of round two of the intervention . Chlamydia positivity in the intervention blocks at the first invitation was the same as in the control block ( 4.3 % ) and 0.2 % lower at the third invitation ( odds ratio 0.96 ( 95 % confidence interval 0.83 to 1.10 ) ) . No substantial decreases in positivity were seen after three screening rounds in any region or sociodemographic group . Among the people who participated three times ( 2.8 % of all invitees ) , positivity fell from 5.9 % to 2.9 % ( odds ratio 0.49 ( 0.47 to 0.50 ) ) . Conclusions There was no statistical evidence of an impact on chlamydia positivity rates or estimated population prevalence from the Chlamydia Screening Implementation programme after three years at the participation levels obtained . The current evidence does not support a national roll out of this register based chlamydia screening programme . Trial registration NTR 3071 ( Netherl and s Trial Register , www.trialregister.nl ) Background : To assess the covariates of alcohol abuse and the association between alcohol abuse , high-risk sexual behaviors and sexually transmitted infections ( STIs ) . Methods : Two thous and and nineteen women aged 20 to 44 were r and omly selected in a 2-stage sampling from the Moshi urban district of northern Tanzania . Participant ’s demographic and socio-economic characteristics , alcohol use , sexual behaviors , and STIs were assessed . Blood and urine sample s were drawn for testing of human immunodeficiency virus , herpes simplex virus , syphilis , chlamydia , gonorrhea , trichomonas , and mycoplasma genitalium infections . Results : Adjusted analyses showed that a history of physical ( OR = 2.05 ; 95 % CI : 1.06–3.98 ) and sexual violence ( OR = 1.63 ; 95 % CI : 1.05–2.51 ) was associated with alcohol abuse . Moreover , alcohol abuse was associated with number of sexual partners ( OR = 1.66 ; 95 % CI : 1.01–2.73 ) . Women who abused alcohol were more likely to report STIs symptoms ( OR = 1.61 ; 95 % CI : 1.08–2.40 ) . Women who had multiple sexual partners were more likely to have an STI ( OR = 2.41 ; 95 % CI : 1.46–4.00 ) compared to women with 1 sexual partner . There was no direct association between alcohol abuse and prevalence of STIs ( OR = 0.86 ; 95 % CI : 0.55–1.34 ) . However , alcohol abuse was indirectly associated with STIs through its association with multiple sexual partners . Conclusions : The findings of alcohol abuse among physically and sexually violated women as well as the association between alcohol abuse and a history of symptoms of STIs and testing positive for STIs have significant public health implication s. In sub-Saharan Africa , where women are disproportionately affected by the HIV epidemic screening for alcohol use should be part of comprehensive STIs and HIV prevention programs Background : Noninvasive molecular tests for bacterial sexually transmitted infections ( STIs ) provide new opportunities for testing in non clinical setting s. Little information is available on the outcomes when applied to asymptomatic sex survey participants . Objective : The objective of this study was to examine patient treatment preferences and partner notification outcomes among Chlamydia trachomatis-positive cases identified in the 2000 national survey of sexual attitudes and lifestyles ( Natsal 2000 ) , and factors associated with providing a urine sample . Methods : The authors conducted a stratified probability sample survey of 11,161 men and women aged 16 to 44 years residing in Britain using computer-assisted self-interviews . Urine testing was performed for C. trachomatis offered to a r and om half of sexually active respondents aged 18 to 44 using ligase chain reaction . Notification , treatment , and follow up of ligase chain reaction-positive respondents were undertaken . Results : A total of 5105 respondents were invited to provide a urine sample . A total of 3628 ( 71 % ) agreed and 3608 sample s were successfully tested . Willingness to provide a urine sample was significantly higher among those reporting previous homosexual experience , heterosexual anal sex , and STI diagnosis . Seventy-three respondents ( 31 men and 42 women ) were diagnosed with genital chlamydial infection . Sixty-five ( 89 % ) responded to notification of their infection and were recommended for treatment and partner notification . Fifty ( 77 % ) respondents preferred to be seen by their general practitioner and 15 ( 23 % ) by their local genitourinary medicine clinic . Although physician feedback on treatment and partner notification outcomes was obtained for only half ( n = 34 ) of respondents , follow-up respondent interviews confirmed that a total of 49 ( 75 % ) respondents underwent this process . Interpretation : In this community-based survey , the rate of provision of urine sample s was high , and those who provided sample s were found to be at somewhat greater risk of infection on average . This was accounted for in estimating population chlamydia prevalence . The authors found that treatment and partner notification of newly diagnosed infections can be successfully achieved in STI prevalence studies BACKGROUND Opportunistic testing and screening for genital chlamydia infection in sexually active women under the age of 25 years can lead to a reduction in chlamydia infection and its related morbidity . AIMS To explore the barriers to testing for genital chlamydial infection in primary care . DESIGN OF STUDY Qualitative study with focus groups . SETTING Rural and urban general practice in Southwest Engl and . METHODS Focus groups were held with r and omly selected high- and lowtesting general practice s in Herefordshire , Gloucestershire and Avon . The high- and low-testing practice s did not differ in their age/sex make-up , or by deprivation indices . Open questions were asked about the management of genitourinary symptoms and opportunistic testing for chlamydia . Data were collected and analysed concurrently until saturation occurred . RESULTS Although staff from high test rate practice s were much more aware of the evidence for opportunistic chlamydia testing and screening , none of the practice s were happy to discuss chlamydia in a consultation unrelated to sexual health . The greatest barriers to opportunistic chlamydia testing and screening were lack of knowledge of the benefits of testing , when and how to take specimens , lack of time , worries about discussing sexual health , and lack of guidance . Healthcare staff stated that any increased testing should be accompanied by clear , concise primary care trust guidance on when and how to test , including how to obtain informed consent and perform contact tracing . Staff felt that testing could be undertaken at family planning clinics or with cervical smears if patients received information before the consultation . Alternatively , in larger practice s specific chlamydia clinics could be held . CONCLUSION The Department of Health needs to be aware of the extreme pressures that primary care staff are under , and the potential barriers to any screening implementation . Efforts to increase chlamydia screening in this setting should be accompanied by clear guidance and education . Any chlamydia clinics or increased testing must have appropriate financial and staff re sources . Genitourinary medicine ( GUM ) clinics , or level three practice s with GUM expertise , will need to be increased in parallel with testing in primary care to provide appropriate contact tracing and follow-up PURPOSE Sexually transmitted infection ( STI ) transmission models propose that incident STIs are related to exposure to infected sex partners . The objective of this study was to determine whether the prevalence of STIs among the available pool of sex partners in a neighborhood , measured indirectly , is an independent determinant of a current incident STI . METHODS The target population comprised 58,299 English-speaking , sexually active 15- to 24-year-olds in 486 census block groups ( CBGs ) in Baltimore , MD . A sample of 65 CBGs was selected using a stratified , systematic , probability-proportional-to-size strategy and 13,873 households were r and omly selected . From 2004 through 2007 , research assistants administered an audio computer-assisted interview survey and collected biologic sample s for gonorrhea and chlamydia testing .  RESULTS The final sample size included 575 participants from 63 CBGs . Additional data provided gonorrhea prevalence from 2004 through 2005 per 15- to 49-year-old persons per 100,000 per CBG . After adjustment for individual-level STI risk factors in a multilevel probability model , adolescents and young adults living in high ( vs. low ) prevalence STI areas were 4.73 times ( 95 % confidence interval [ CI ] : 3.65 - 6.15 ) more likely to have a current incident STI . CONCLUSIONS To inform prevention programs , future research should focus on identifying mechanisms through which context causes changes in local sexual networks and their STI prevalence Background A selective , systematic , Internet-based , Chlamydia Screening Implementation for 16 to 29-year-old residents started in three regions in the Netherl and s in April 2008 : in the cities of Amsterdam and Rotterdam and a more rural region , South Limburg . This paper describes the evaluation design and discusses the implication s of the findings from the first screening round for the analysis . The evaluation aims to determine the effects of screening  on the population prevalence of Chlamydia trachomatis after multiple screening rounds . Methods A phased implementation or ' stepped wedge design ' was applied by grouping neighbourhoods ( hereafter : clusters ) into three r and om , risk-stratified blocks ( A , B and C ) to allow for impact analyses over time and comparison of prevalences before and after one or two screening rounds . Repeated simulation of pre- and postscreening Chlamydia prevalences was used to predict the minimum detectable decline in prevalence . Real participation and positivity rates per region , block , and risk stratum ( high , medium , and low community risk ) from the 1st year of screening were used to substantiate predictions . Results The results of the 1st year show an overall participation rate of 16 % of 261,025 invitees and a positivity rate of 4.2 % , with significant differences between regions and blocks . Prediction by simulation methods adjusted with the first-round results indicate that the effect of screening ( minimal detectable difference in prevalence ) may reach significance levels only if at least a 15 % decrease in the Chlamydia positivity rate in the cities and a 25 % decrease in the rural region after screening can be reached , and pre- and postscreening differences between blocks need to be larger . Conclusions With the current participation rates , the minimal detectable decline of Chlamydia prevalence may reach our defined significance levels at the regional level after the second screening round , but will probably not be significant between blocks of the stepped wedge design . Evaluation will also include other aspects and prediction models to obtain rational advice about future Chlamydia screening in the Netherl and Background DNA amplification assays are increasingly being used to facilitate the testing of asymptomatic individuals for urogenital Chlamydia trachomatis . The long-term clinical benefit in terms of avoided infertility and ectopic pregnancy is unknown . Methods In 1997 , 15 459 women and 14 980 men aged 21–23 years were living in Aarhus County , Denmark . A r and om sample of 4000 women and 5000 men was contacted by mail and offered the opportunity to be tested for C trachomatis by means of a sample obtained at home and mailed directly to the laboratory .  The remaining 11 459 women and 9980 men received usual care  and constituted the control population . All men and women were subsequently followed for 9 years by the use of Danish health registers . Data were collected on pelvic inflammatory disease ( PID ) , ectopic pregnancy ( EP ) , infertility diagnoses , in-vitro fertilisation ( IVF ) treatment and births in women , and on epididymitis in men . The intervention and control groups were compared using Cox regression analyses and the intention-to-screen principle . Results Among women , no differences were found between the intervention group and the control group : HR ( 95 % CI ) for PID 1.12 ( 0.70 to 1. 
    Output:
    
Conclusions A variety of strategies have been used in home-based CT/NG screening programs .