High-risk Types of Human Papillomavirus (HPV) DNA in Oral and Genital Mucosa of Infants During Their First 3 Years of Life: Experience from the Finnish HPV Family Study

Background: This study is aimed to clarify data on the acquisition, persistence, and clearance of high-risk types of human papillomavirus (HPV) DNA from the mucosa and the determinants of persistent mucosal HPV infection in infants.

Methods: Oral and genital scrapings from 324 infants were collected at birth, 3 days after delivery, and 1, 2, 6, 12, 24, and 36 months after delivery and tested for the presence of HPV DNA by nested polymerase chain reaction and hybridization with 12 high-risk HPV oligoprobes. HPV status and demographic data for parents were analyzed.

Results: During the follow-up period (median duration, 26.2 months), HPV DNA was found to be present in 12%-21% of oral scrape samples and in 4%-15% of genital scrape samples obtained from the infants. Oral HPV infection was acquired by 42% of children, cleared by 11%, and persisted in 10% of the infants, whereas 37% were never infected. The corresponding figures for genital HPV infection were 36%, 14%, 1.5%, and 47%. Kaplan-Meier analysis revealed that both the cumulative incidence of infection and clearance of HPV were parallel in oral and genital sites. Persistent oral HPV infection in the child was significantly associated with persistent oral HPV infection in the mother at month 36 of follow-up, hand warts in the mother, young age at onset of sexual activity for the mother, and the mother's use of oral contraception, as well as with the father's oral HPV status at 24 months. Persistent genital HPV infection in the infant was predicted by if the mother had started smoking at 18-21 years of age and by a history of genital warts.

Conclusions: Persistent carriage of high-risk HPV types was detected in oral and genital mucosa specimens obtained from 10% and 1.5% of the infants during their first 26 months of life. The rates of acquisition and clearance of HPV were similar in oral and genital mucosa.