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

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.