Estimating HPV DNA Deposition Between Sexual Partners Using HPV Concordance, Y Chromosome DNA Detection, and Self-reported Sexual Behaviors

Abstract

Background: Detection of human papillomavirus (HPV) DNA in genital samples may not always represent true infections but may be depositions from infected sexual partners. We examined whether sexual risk factors and a biomarker (Y chromosome DNA) were associated with genital HPV partner concordance and estimated the fraction of HPV detections potentially attributable to partner deposition.

Methods: The HITCH study enrolled young women attending a university or college in Montréal, Canada, and their male partners, from 2005 to 2010. We tested baseline genital samples for Y chromosome DNA and HPV DNA using polymerase chain reaction.

Results: Type-specific HPV concordance was 42.4% in partnerships where at least one partner was HPV DNA positive. Y chromosome DNA predicted type-specific HPV concordance in univariate analyses, but in multivariable models the independent predictors of concordance were days since last vaginal sex (26.5% higher concordance 0-1 vs 8-14 days after last vaginal sex) and condom use (22.6% higher concordance in never vs always users). We estimated that 14.1% (95% confidence interval [CI], 6.3-21.9%) of HPV DNA detections in genital samples were attributable to vaginal sex in the past week.

Conclusions: A substantial proportion of HPV DNA detections may be depositions due to recent unprotected vaginal sex.

Keywords: concordance; deposition; human papillomavirus; sexual behavior; transmission.

Figure 1.

Type-specific human papillomavirus (HPV) DNA partner concordance prevalence (conditional on either partner being infected with a type) by the proportion of male cells (with Y chromosome DNA) among women’s exfoliated vaginal cells, as predicted by spline regression and linear generalized estimation equation (GEE) regression models. The more flexible spline regression is shown for comparison to provide qualitative verification that the linear regression appropriately models the data. The linear GEE regression model includes a square root transformation of the proportion of male cells to account for the nonlinear relationship. Dashed lines are the 95% confidence intervals predicted by linear regression. The x axis is on a logarithmic scale. Abbreviation: CI, confidence interval.

Figure 2.

Additional type-specific human papillomavirus (HPV) DNA partner concordance (conditional on either partner being HPV DNA positive) predicted by linear generalized estimation equation (GEE) regression by days since last vaginal sex and by self-reported condom use. Women who reported last having vaginal sex ≥4 days ago are the reference category (ref). Differences are adjusted for frequency of vaginal sex acts ( per week), frequency of digital sex, man’s number of lifetime sexual partners, and cumulative number of vaginal sex acts since the start of the partnership.