Directionality of Genital Human Papillomavirus Infection Transmission Within Heterosexual Couples: A Systematic Review and Meta-analysis

Abstract Background Limited evidence indicates greater female-to-male (F–M) transmission of genital infection with human papillomavirus (HPV) relative to male-to-female (M–F). We verified the hypothesis of a differential transmission rate in couple-based studies by conducting a systematic review and meta-analysis. Methods We searched MEDLINE, EMBASE, Scopus, and Cochrane Library databases for studies published until December 2019. We calculated pooled estimates of F–M and M–F transmission rates and their rate differences per 100 person-months, with 95% confidence intervals (CI), using a random-effects model. We counted occurrences of directionality preponderance for each HPV type. Results We identified 7 eligible studies published between 2008 and 2019, providing data for 752 couples. Pooled estimates for F–M and M–F transmission rates were 3.01 (95% CI, 1.19–7.64; I2 = 97%) and 1.60 (95% CI, 0.86–2.98; I2 = 89%), respectively. The overall rate difference was 0.61 (95% CI, −0.27 to 1.49; I2 = 75%). Three studies provided rates by sex and HPV genotype; 2 favored a preponderance of F–M and 1 favored M–F transmission. Conclusions There was slight evidence for a differential transmission rate favoring higher F–M than M–F transmission with substantial statistical heterogeneity across studies. There is limited published evidence supporting higher female-to-male than male-to-female human papillomavirus transmission. There is significant heterogeneity among studies; however, future transmission investigations should consider factors such as age and recency of relationships as key variables.