D it causes morbidity and mortality in both men and women via cervical cancer, penile and anal cancer, oropharyngeal cancer and genital warts (GW) [1]. In many countries HPV Ornipressin msds prevalence is similar among men and women, with differences dependent on risk factors and methods used to detect infection [1?]. While much of the emphasis in the literature has focused on women and the link between HPV and cervical cancer, evidence is mounting regarding the high prevalence of HPV infection in males, particularly in anogenital sites, and especially in men who have sex with men (MSM) [3]. Studies from developed countries have found a high prevalence of HPV and anal lesions among MSM [3] but data from developing countries are also emerging. For example, a recent study in Peru among 105 MSM found that 77.1 werePLOS ONE | www.plosone.orginfected with HPV of which nearly half ?47.3 — were infected by a carcinogenic type [4]. Similarly, a study in Argentina which included a sample (N = 114) of transgendered (TG) sex workers reported an anal HPV prevalence of 97 and high-risk genotypes were detected in 87.5 of participant samples from which the infecting genotype was determined [5]. While it is well established that anogenital warts are caused by HPV and that HPV is linked to oral, anal and penile neoplasms [6], HPV infection has also been associated with acquisition of HIV in MSM [7?], and there are ongoing studies looking at the association between GW and HIV [10]. Unfortunately, there is little public awareness about the HPV infection, and perhaps less-so in high risk groups [11]. Existing research has focused on women’s limited knowledge and susceptibility to HPV infection and its sequelae, most notably, cervical cancer [11]; however, there has been less empirical workHPV and Genital Warts in Peruvian MSM: Experiencesexamining men’s knowledge, attitudes and experiences regarding HPV infection and its disease outcomes [12?5]. Additionally, highly vulnerable populations such as TG and MSM who perform sex work remain under-represented in the studies on this topic. In addition to the physiological consequences of HPV-related GW, research is emerging with regards to the social and psychological implications of HPV including its negative impact on quality of life, mental wellbeing and sexual practices [16?7], [18]. One study [19] explored the experience of having GW among MSM, concluding that MSM need to be appropriately informed about all aspects of GW, with the aim of alleviating the psychological distress associated with the disease and to optimize preventive Pyrvinium embonate custom synthesis efforts and safe sexual behaviour. Of course, these aspects need to be considered in the light of a major context in which social exclusion, limitations of the health system and STI-related stigma affect the access of MSM/TG populations to health care. For example, recent studies in Peru have found that, in these groups, fear of a positive HIV result and lack of awareness of places where to get tested are important reasons for not taking an HIV test [20]; and that conditions of social vulnerability define for them a situation of high risk and prevalence of HIV and other STI, especially among TG people [21?2]. In this paper we present findings of a qualitative study aimed to explore the knowledge, attitudes and experiences of Peruvian MSM and male-to-female TG regarding HPV and GW.ProceduresFocus Groups.. The focus groups were primarily aimed to obtain socially shared ideas regarding HPV and GW (.D it causes morbidity and mortality in both men and women via cervical cancer, penile and anal cancer, oropharyngeal cancer and genital warts (GW) [1]. In many countries HPV prevalence is similar among men and women, with differences dependent on risk factors and methods used to detect infection [1?]. While much of the emphasis in the literature has focused on women and the link between HPV and cervical cancer, evidence is mounting regarding the high prevalence of HPV infection in males, particularly in anogenital sites, and especially in men who have sex with men (MSM) [3]. Studies from developed countries have found a high prevalence of HPV and anal lesions among MSM [3] but data from developing countries are also emerging. For example, a recent study in Peru among 105 MSM found that 77.1 werePLOS ONE | www.plosone.orginfected with HPV of which nearly half ?47.3 — were infected by a carcinogenic type [4]. Similarly, a study in Argentina which included a sample (N = 114) of transgendered (TG) sex workers reported an anal HPV prevalence of 97 and high-risk genotypes were detected in 87.5 of participant samples from which the infecting genotype was determined [5]. While it is well established that anogenital warts are caused by HPV and that HPV is linked to oral, anal and penile neoplasms [6], HPV infection has also been associated with acquisition of HIV in MSM [7?], and there are ongoing studies looking at the association between GW and HIV [10]. Unfortunately, there is little public awareness about the HPV infection, and perhaps less-so in high risk groups [11]. Existing research has focused on women’s limited knowledge and susceptibility to HPV infection and its sequelae, most notably, cervical cancer [11]; however, there has been less empirical workHPV and Genital Warts in Peruvian MSM: Experiencesexamining men’s knowledge, attitudes and experiences regarding HPV infection and its disease outcomes [12?5]. Additionally, highly vulnerable populations such as TG and MSM who perform sex work remain under-represented in the studies on this topic. In addition to the physiological consequences of HPV-related GW, research is emerging with regards to the social and psychological implications of HPV including its negative impact on quality of life, mental wellbeing and sexual practices [16?7], [18]. One study [19] explored the experience of having GW among MSM, concluding that MSM need to be appropriately informed about all aspects of GW, with the aim of alleviating the psychological distress associated with the disease and to optimize preventive efforts and safe sexual behaviour. Of course, these aspects need to be considered in the light of a major context in which social exclusion, limitations of the health system and STI-related stigma affect the access of MSM/TG populations to health care. For example, recent studies in Peru have found that, in these groups, fear of a positive HIV result and lack of awareness of places where to get tested are important reasons for not taking an HIV test [20]; and that conditions of social vulnerability define for them a situation of high risk and prevalence of HIV and other STI, especially among TG people [21?2]. In this paper we present findings of a qualitative study aimed to explore the knowledge, attitudes and experiences of Peruvian MSM and male-to-female TG regarding HPV and GW.ProceduresFocus Groups.. The focus groups were primarily aimed to obtain socially shared ideas regarding HPV and GW (.