Human papillomavirus prevalence in the genital tract of asymptomatic men

virological and epidemiological aspects

Abstract

Currently, genital tract infection by human papillomavirus (HPV) is the most prevalent sexually transmitted virosis in the world. However, there are still gaps in knowledge regarding the etiology of penile cancer, and the pathogenic processes of HPV in men are not completely understood, especially in cases of subclinical infections. This study aimed to determine the prevalence of HPV infection in penile swab samples, derived from a clinically asymptomatic male population. For this purpose, 261 samples were analysed, collected between 2010 and 2013 in different institutions of the city of Rio de Janeiro, including hospitals , a laboratory of clinical analysis, and a metallurgical company. Also, we have recorded epidemiological variables of 182 of these individuals, through the application of a questionnaire to aid the investigation of possible risk factors. The viral identification and typing was made by the generic and type-specific Polymerase Chain Reaction and the RFLP (Restriction Fragment Length Polimorfism) techniques, after the extraction of genetic material by the phenol-chloroform technique. The overall HPV infection prevalence was 16.47% (43 individuals). The most prevalent HPV type was the HPV 6 (34.88%), followed by HPV 11 (16.27%), HPV 16 (23.25%) , HPV 45 (9.30%) and HPV 58 (2.32%), so we have found HPV infection by the low oncogenic risk typesin 53.66%, and by the high oncogenic risk types in 46.34% of the infected individuals. The age of the studied subjects ranged between 18 and 65 years, with a mean age of 26.30 years. Among the epidemiological variables, statistical significance was found among the group of men who have sex with men, and the group which declared to have kept anal intercourse during sexual relations. There was no detection circumcised individuals. Two of the three individuals who reported having previous history of Sexual Transmitted Disease were infected. Thus, we could infer that the prevalence of the infection in the asymptomatic male population is considerable, and we believe that the results have contributed to a statistically more clear and realistic view about the behavior and epidemiology of HPV in the general male population. Keyword: HPV, STD, men, asymptomatic, subclinical infection, PCR.