Human Papillomavirus Persistence, Recurrence, and Incidence in Early Childhood.

BACKGROUND Little is known on the vertical transmission of human papillomavirus (HPV) and on the dynamics of HPV among children. Our objective was to determine the risk of HPV recurrence, persistence, and incidence over 2 years of age among children born to HPV-positive mothers. METHODS We conducted the HERITAGE study among pregnant women recruited between 2010 and 2016 in Canada. HPV DNA testing was done on vaginal samples collected during the first and third trimesters of pregnancy, and on conjunctival, oral, pharyngeal, and genital samples collected in children from birth and at every 3-6 months up to 2 years. We estimated the probability of HPV vertical transmission, and of HPV recurrence, persistence, and incidence among children during follow-up. Time to clear HPV among children was estimated using Kaplan-Meier technique. RESULTS Among the 422 women with HPV during pregnancy, 390 carried pregnancy to term, and 395 children were born alive including twins/triplets. HPV vertical transmission was estimated at 7.3% (95% confidence interval [CI], 5.0%-10.4%) with a genotype concordance of 85.2%. During the entire follow-up, we observed 91 HPV detections (among 51 children) including 2 recurrent and 1 persistent. Incident genotypes occurred in 26 of the 270 (9.6%) children with valid HPV testing during follow-up. Most HPV infections detected in children cleared with a mean time of 3.9 months (95% CI, 3.6-4.2 months). CONCLUSIONS HPV vertical transmission and incident HPV occasionally occur during infancy, but the risk of persistence or recurrence is overall very low.