Detection of human papillomavirus subtypes harbored in the foreskin of asymptomatic boys: Controlled study

Introduction: Human papillomavirus infection (HPV) is one of the most common sexually transmitted infections and can cause penile and anal cancer in men, and invasive cervical cancer in women.

Objective: To evaulate the colonization of 32 HPV subtypes in the foreskin of boys.

Study design: A prospective analysis was made of the data of 62 healthy boys who had undergone standard circumcision. Deoxyribonucleic acid (DNA) was isolated from the foreskin tissues, and the integrity of DNA was tested. The DNA of each patient was further assessed with real-time polymerase chain reaction (PCR) and the presence of 32 subtypes of HPV was explored. To confirm the results, melting curve analysis and agarose gel electrophoresis (AGE) were performed for all samples. Further analysis was made using LCD-array on six randomly selected samples to confirm the results together with negative and positive controls.

Results: The mean age of the boys was 6.8 ± 2 years at the time of surgery. All positive controls and samples were positive, all negative controls were negative in the first HPV amplification assay. All positive controls had typical melting curve peaks, whereas all sample amplifications had non-specific, atypical melting curves not fitting with those of the positive controls. Two bands of expected sizes (124 and 405 bp) were only observed in positive controls, but not in negative controls or samples on AGE. The same results were observed on the 6 randomly selected samples using LCD-array. Consequently, all the foreskin samples were evaluated as negative for the 32 HPV types investigated in the study.

Discussion: Literature shows a high prevalence of genital HPV in newborns, in early infancy, late adolescence and adulthood. However there is a lack of data in literature on the prevalence in early and late childhood. The negative results of HPV colonization on the foreskin in the current study may be attributed to the conservative and mostly monogamous nature of most family structures in Turkey.

Conclusion: The results of the present study have shown that foreskin tissue is not a natural reservoir for HPV and subclinical HPV infection is not likely in the absence of suspected sexual contact.