***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: UNLABELLED In Rakai , Ug and a , human immunodeficiency virus (HIV)-positive men were r and omized to undergo either immediate circumcision ( intervention arm ) or delayed circumcision ( control arm ) . Penile swab sample s were assayed for high-risk human papillomavirus ( HR-HPV ) by Roche HPV Linear Array at enrollment and at 24 months ( intervention arm , 103 subjects ; control arm , 107 subjects ) . Rate ratios ( RRs ) of HR-HPV were estimated by Poisson regression . At 24 months , HR-HPV prevalence was found in 57 ( 55.3 % ) of 103 subjects in the intervention arm and in 77 ( 71.7 % ) of 107 subjects in the control arm ( RR , 0.77 ; 95 % confidence interval [ CI ] , 0.62 - 0.97 ) . Multiple HR-HPV infections were found in 19 ( 22.4 % ) of 85 subjects in the intervention arm and in 45 ( 42.5 % ) of 106 subjects in the control arm ( RR , 0.53 ; 95 % CI , 0.33 - 0.83 ) . New HR-HPV genotypes were acquired by 34 ( 42.0 % ) of 81 subjects in the intervention arm and by 53 ( 57.0 % ) 85 subjects in the control arm ( RR , 0.74 ; 95 % CI , 0.54 - 1.01 ; P = .06 ) . Multiple new HR-HPV genotypes were acquired by 8 ( 9.9 % ) of 81 subjects in the intervention arm and by 23 ( 24.7 % ) of 93 subjects in the control arm ( RR , 0.40 ; 95 % CI , 0.19 - 0.84 ; P = .01 ) . Circumcision did not affect the acquisition of single HR-HPV infections ( RR , 1.00 ; 95 % CI 0.65 - 1.53 ) or clearance of HR-HPV infections ( RR , 1.09 ; 95 % CI 0.94 - 1.27 ) . Circumcision of HIV-positive men reduced the prevalence and incidence of multiple HR-HPV infections . TRIAL REGISTRATION Clinical Trials.gov identifier : NCT00124878 No data is yet available on incidence or persistence of human papillomavirus ( HPV )  infection in men . We enrolled 374 younger male conscripts ( 18 - 29 years ) in a prospect i ve study , and they were examined twice with an interval of 6 to 8 months . Data collection included a question naire and a sample of cells from the penis for HPV detection using PCR . In addition , the presence of Chlamydia trachomatis DNA was assessed in urine sample s by means of PCR . The HPV prevalence at the first and second examinations was 33.8 % and 31.9 % , respectively . The acquisition rate of HPV ( overall ) during follow-up was 13.8 % , and nearly one fourth of the participants were HPV positive at both examinations . Number of sex partners during follow-up was the most important risk factor for acquiring HPV ( odds ratio , 17.2 ; 95 % confidence interval , 4.6 - 64.7 , for ≥3 partners versus ≤1 partner ) . In contrast , acquisition of a new HPV type in initially HPV-positive men was strongly related to having multiple HPV types at enrollment ( OR , 4.1 ; 95 % confidence interval , 1.4 - 12.3 ) . This was also the most important risk factor for HPV persistence together with current smoking and having a high-risk HPV type at enrollment . This is the first study to assess risk factors for acquisition and persistence of HPV . The sexually transmitted nature of the infection is confirmed , and the data point to an important role of having multiple HPV types for persistence Aim : To study the epidemiology of different human papillomavirus ( HPV ) genotypes in cervical sample s of HIV-1-infected women with normal Papanicolau smears . Design : Retrospective analysis of a prospect i ve cohort . Patients and Methods : We selected HIV-1-infected women with 2 consecutive normal Papanicolau smears at baseline and at least 1 baseline and 1 follow-up cervical sample .  HPV infection was assessed by second-generation hybrid capture ( HC-2 ) and multiplex polymerase chain reaction ( mPCR ) .  HPV genotypes were determined by mPCR . Results : From a cohort of 139 women followed up to 4 years , 93 women meeting the inclusion criteria were analyzed . The mean period between sample s was 20 months ( range , 6 - 44 months ) . HPV baseline prevalence was 63 % [ 59/93 ; 95 % confidence interval ( CI ) , 53 % to 73 % ] using polymerase chain reaction and 41 % ( 38/93 ; 95 % CI , 31 % to 51 % ) using HC-2 , P = 0.007 ( kappa , 0.45 ; P = 0.001 ) . The most prevalent high oncogenic risk genotypes ( HR-HPV ) were HPV-16 ( 28 % ) , HPV-33 ( 18 % ) , HPV-52 ( 12 % ) , HPV-58 ( 11 % ) , and HPV-39 ( 11 % ) . Infection with multiple HPV genotypes was detected in > 40 % of women . HPV infection persisted at follow-up in 86 % ( 51/59 ; 95 % CI , 77 % to 95 % ) by polymerase chain reaction and 76 % ( 29/38 ; 95 % CI , 62 % to 90 % ) by HC-2 . HPV infection persisted in 55 % of women with sample s available beyond 3 years . The actuarial probabilities of clearance and incidence of HPV infection at 36 months were 16 % and 45 % , respectively . Conclusions : HPV infection is highly prevalent and persistent among HIV-1-infected women with normal Papanicolau smears .  HR-HPV genotypes other than HPV-16 ( HPV-33 , HPV-52 ) are frequently detected in HIV-infected women .  mPCR provides better surveillance of HPV infection than HC-2 methods Background : Knowledge about the incidence , clearance , and factors associated with  human papilloma virus ( HPV ) infection in men is lacking , and much of what is available focuses on high-risk groups . Methods : A prospect i ve cohort study was carried out with 504 heterosexual males from Mexico State , Mexico . Participants were monitored for 4 years at intervals of approximately 4 months , with a median total duration of follow-up of 19.8 months . The presence of cervical HPV in female sexual partners was evaluated as a risk factor .  HPV DNA testing was conducted using the polymerase chain reaction technique . Risk factors associated with the incidence and clearance of HPV infection were evaluated through survival analysis . Results : The cumulative incidence of infection with any HPV type at 12 months was 15 % [ 95 % confidence interval ( CI ) , 0.12–0.20 ] . About 72 % of men with incident HPV cleared the infection by 12 months . The presence of cervical HPV in a man 's female sex partner was the main determinant for males acquiring HPV infection of any type [ adjusted HR ( AHR ) , 2.1 ; 95 % CI , 1.1–3.8 ] and oncogenic HPV infection ( AHR , 4.1 ; 95 % CI , 2.1–8.0 ) , while having a history of anal sexual relations with women was statistically associated with acquiring nononcogenic HPV ( AHR , 1.8 ; 95 % CI , 1.1–2.9 ) . Conclusions and Impact : The incidence of genital HPV infection in this population is relatively low , with relatively quick acquisition and clearance rates . Cervical HPV infection in men 's female sexual partners was the main risk factor for genital HPV infection in men . Cancer Epidemiol Biomarkers Prev ; 21(11 ) ; 1956–65 . © 2012 AACR BACKGROUND Anal cancer remains rare ( incidence of about 1·5 per 100,000 women yearly ) , but rates are increasing in many countries . Human papillomavirus ( HPV ) 16 and 18 infections cause most cases of anal cancer . We assessed efficacy of an AS04-adjuvanted HPV 16 and HPV 18 vaccine against anal infection with HPV 16 , HPV 18 , or both ( HPV 16/18 ) . METHODS Women from Costa Rica were registered between June 28 , 2004 , and Dec 21 , 2005 , in a r and omised double-blind controlled trial that was design ed to assess vaccine efficacy against persistent cervical HPV 16/18 infections and associated precancerous lesions . Eligible women were residents of Guanacaste and selected areas of Puntarenas , Costa Rica , age 18 - 25 years , in good general health , willing to provide informed consent , and were not pregnant or breastfeeding . Participants were r and omly assigned ( 1:1 ) to receive an HPV vaccine ( Cervarix , GlaxoSmithKline , Rixensart , Belgium ) or a control hepatitis A vaccine ( modified preparation of Havrix , GlaxoSmithKline , Rixensart , Belgium ) . Vaccines were administered in three 0·5 mL doses at enrolment , 1 month , and 6 months . Women , selected at the final blinded study visit 4 years after vaccination , provided anal specimens for assessment of vaccine efficacy against anal HPV 16/18 infection . Prevalence of anal HPV 16/18 infections , reported as vaccine efficacy , was the primary endpoint of the study described here . Vaccine efficacy against cervical HPV 16/18 infection in the same women at the 4-year visit was used as a comparator . Analyses were done in a restricted cohort of women who were negative for both cervical HPV 16 and HPV 18 DNA and who were HPV 16 and HPV 18 seronegative before enrolment ( HPV naive ) , and also in the full cohort of women who provided an anal specimen . Investigators were masked to group assignment . This study is registered at Clinical Trials.gov , number NCT00128661 . FINDINGS All women who attended the final blinded study visit and consented to anal specimen collection were included in the analysis ( 4210 of 6352 eligible women ) . In the full cohort , vaccine efficacy against prevalent HPV 16/18 infection measured one-time , 4 years post vaccination was lower at the anus ( 62·0 % , 95 % CI 47·1 - 73·1 ) compared with the cervix ( 76·4 % , 67·0 - 83·5 ; p for interaction by anatomical site 0·031 ) . In the restricted cohort , vaccine efficacy against anal HPV 16/18 infection was 83·6 % ( 66·7 - 92·8 ) , which was similar to vaccine efficacy against cervical HPV 16/18 infection ( 87·9 % , 77·4 - 94·0 ) . Safety issues were not addressed in the current analysis . Additional safety data will be published later in a separate article . INTERPRETATION The AS04-adjuvanted vaccine affords strong protection against anal HPV infection , particularly among women more likely to be HPV naive at enrolment . FUNDING National Cancer Institute with contributions from the National Institutes of Health Office of Research on Women 's Health . Vaccine was provided by GlaxoSmithKline Biologicals BACKGROUND Infection with human papillomavirus ( HPV ) and diseases caused by HPV are common in boys and men . We report on the safety of a quadrivalent vaccine ( active against HPV types 6 , 11 , 16 , and 18 ) and on its efficacy in preventing the development of external genital lesions and anogenital HPV infection in boys and men . METHODS We enrolled 4065 healthy boys and men 16 to 26 years of age , from 18 countries in a r and omized , placebo-controlled , double-blind trial . The primary efficacy objective was to show that the quadrivalent HPV vaccine reduced the incidence of external genital lesions related to HPV-6 , 11 , 16 , or 18 . Efficacy analyses were conducted in a per- protocol population , in which subjects received all three vaccinations and were negative for relevant HPV types at enrollment , and in an intention-to-treat population , in which subjects received vaccine or placebo , regardless of baseline HPV status . RESULTS In the intention-to-treat population , 36 external genital lesions were seen 
    Output:
    
Within the limitations of the data , there was a general pattern of higher incidence and clearance of non-cervical genital HPV infections , compared to cervical infections .
HIV status , circumcision , number of sex partners and partner HPV status significantly influenced high-risk HPV incidence/clearance at male anogenital sites .
Conclusions Parallels appear to exist between the epidemiology of cervical and non-cervical HPV infections in terms of incidence , HPV-type distribution , and risk factors for infection .
Available data suggest that non-cervical genital HPV infections may occur more frequently , with higher clearance rates , than cervical infections .