Prevalence of Anal Human Papillomavirus Vaccine Types in the Bangkok Men Who Have Sex With Men Cohort Study Ross D. Cranston, MD, FRCP,* Andrew D. Althouse, PhD,† Frits van Griensven, PhD,‡ Laura Janocko, PhD,† Marcel E. Curlin, MD,§¶ Supaporn Chaikummao, BSN,§ Wannee Chonwattana, BSc,§ Aaron Siegel, BA,† Timothy H. Holtz, MD, MPH, FACP,§|| and Ian McGowan, MD, PhD, FRCP*† Background: The quadrivalent human papillomavirus (qHPV) and 9 valent (nHPV) vaccine are licensed for males to prevent anal HPV–associated dysplasia and cancer caused by HPV types 6, 11, 16, and 18 (qHPV) and additional types 33, 35, 45, 52, and 58 (nHPV), respectively. Both condi- tions are common in HIV-infected and HIV-uninfected men who have sex with men (MSM). It is not well documented which anal HPV vaccine types are most prevalent in Southeast Asia. Methods: A convenience sample of 400 anal swabs were obtained from 200 HIV-infected and 200 HIV-uninfected sexually active Bangkok MSM Cohort Study participants. After swab collection in PreservCyt (Cytyc Corp, Marlborough, MA), the media was stored at -80°C until processing. DNA was extracted, amplified by polymerase chain reaction, denatured, and then hybridized to probes for 37 HPV types and β-globin. Results: The mean participant age was 25.6 years (range, 18–55 years); the mean CD4 T-cell count was 410 cells/mm 3 in the HIV-infected partici- pants. Among all swab samples, 386 (192 HIV-positive and 194 HIV- negative) had adequate β-globin for HPV genotype testing. Anal HPV type was detected in 44.3% of participants whose samples underwent genotype testing. Both qHPVand nHPV types were more frequently detected in HIV- infected compared with HIV-uninfected (42.2% vs. 23.2% [P < 0.01], 50.0% vs. 24.2% [P < 0.01]), respectively). There were no significant rela- tionships between social behaviors (alcohol use, drug use) or sexual behav- iors (number of partners, condom usage, sexual positioning) and anal HPV prevalence. Conclusions: The prevalence of anal vaccine HPV types in Thai MSM was similar to that reported in MSM from Western populations and has a similar distribution by HIV status. Targeting young MSM with vaccination could offer protection against HPV vaccine types. T he worldwide incidence of human papillomavirus (HPV)– associated anal cancer is increasing in both men and women, with current annual rates in the United States approximating 2/100,000. 1 In men who have sex with men (MSM), the incidence is similar to that of cervical cancer before the introduction of cervical cytology screening and is approximately 2 to 3 times this rate in HIV-infected MSM. 2,3 Approximately 40 HPV types infect the anogenital area, and these can be broadly differentiated into high-risk (HR) and low-risk types based on their historical association with cervical cancer. More than 80% of all anal cancers are related to persistent infection with HR-HPV infection, with HPV type 16 being the most commonly isolated. 4 Anal HPV–associated disease due to HPV types 6 and 11 (low-risk) and types 16 and 18 (HR) may be prevented in men with the use of the quadrivalent HPV vaccine (qHPV) Gardasil (Merck and Co, Whitehouse Station, NJ). 5,6 This vaccine is indicated for males and females aged 9 to 26 years, with optimal efficacy seen in individuals without evidence of current or past HPV infection. 6 A vaccine with increased valency that additionally incorporates HR-HPV types 31, 33, 45, 52, and 58 (nHPV) Gardasil 9 (Merck and Co) has recently been approved by the US Food and Drug Ad- ministration for boys aged 9 to 15 years. In Western populations, the prevalence of anal HPV in- fection in MSM varies from study to study. Several studies report anal HPV prevalence rates of 45% to 70% in HIV-uninfected and 65% to 96% in HIV-infected MSM, 7–9 and in a recent meta- analysis of HIV-infected MSM, HPV16 was the most frequently detected type at 35.4% (95% confidence interval, 32.9–37.9). 10 In general, HIV-infected MSM also have an increased prevalence of all HPV infections, HR-HPV, and multiple HPVs, compared with HIV-uninfected MSM. 10,11 Although the qHPV was approved by the Thai Food and Drug Administration in 2007, limited information is available From the *Department of Medicine and †Magee-Womens Research Insti- tute, University of Pittsburgh, Pittsburgh, PA; ‡Thai Red Cross AIDS Research Center, Bangkok, Thailand; §Thailand Ministry of Public Health–U.S. Centers for Disease Control and Prevention Collaboration, Nonthaburi, Thailand, ¶Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand; and ||Division of HIV/AIDS Pre- vention, US Centers for Disease Control and Prevention, Atlanta, GA. We are grateful to the participants of the Bangkok Men Who Have Sex With Men Cohort Study. In addition, we are grateful to Sarika Pattanasin for her assistance in securing data for the project; Eileen Dunne, Wipas Wimonsate, and Anupong Chitwarakorn for their critical review of the final manuscript; and Shaun Burneisen for his laboratory work on human papillomavirus detection. Conflict of Interest: R.D.C. has received institutional research funding from Merck and Co. Presented in abstract: International Papillomavirus Meeting; San Juan, Puerto Rico; 2012. Funding source: US Centers for Disease Control and Prevention. Contributions: Study conception/design: R.D.C., I.M., F.V.G., M.E.C., S.C. Study sample collection: S.C., W.C. Study data analysis and interpretation: R.D.C., A.D.A., I.M., F.V.G., M.E.C., W.C., T.H.H. Involvement in drafting and revising the manuscript: R.D.C., I.M., A.D.A., F.V.G., M.E.C., S.C., W.C., T.H.H. Gave approval of the final draft for publication: R.D.C., I.M., A.D.A., F.V.G., L.J., A.S., M.E.C., T.H.H., S.C., W.C. Overall responsibility for accuracy and integrity of the research: R.D.C., I.M., F.V.G., M.E.C., T.H.H. Centers for Disease Control and Prevention (CDC) Disclaimer: The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the CDC. Use of trade names is for identification purposes only and does not constitute endorsement by the CDC or the Department of Health and Human Services. Correspondence: Ross D. Cranston, MD, FRCP, Department of Medicines, University of Pittsburgh, 3520 Fifth Ave, Suite 510, Pittsburgh, PA 15213. E-mail: rdc27@pitt.edu. Received for publication March 26, 2015, and accepted September 23, 2015. DOI: 10.1097/OLQ.0000000000000372 Copyright © 2015 American Sexually Transmitted Diseases Association All rights reserved. ORIGINAL STUDY Sexually Transmitted Diseases • Volume 00, Number 00, Month 2015 1 Copyright © 2015 by the American Sexually Transmitted Diseases Association. Unauthorized reproduction of this article is prohibited.