Vaginal and Penile Microbiome Associations with HSV-2 in Women and their Male Sex Partners.

BACKGROUND We determined how the vaginal and penile microbiomes contribute to HSV-2 serostatus within sexual partnerships. METHODS Microbiomes were characterized in cervicovaginal lavage and penile meatal swab through high-throughput 16s ribosomal RNA gene amplicon sequencing. HSV-2 antibody was detected in serum. We modeled vaginal and penile taxa and covariates contributing to HSV-2 status in women and men using bivariate probit. RESULTS Among 231 couples, HSV-2 was detected in: 78 (33.8%) both the man and woman, 52 (22.5%) woman only, 27 (11.7%) man only, 74 (32.0%) neither. Women were median age 22 years, 10.9% with HIV, 21.4% with Bacterial vaginosis (BV). Men were median age 26 years, 11.8% with HIV, 55.0% circumcised. In analysis adjusted for sociodemographics and BV, enrichment of vaginal Gardnerella vaginalis and Lactobacillus iners was associated with increased likelihood of HSV-2 in women and HSV-2 in male partners. Penile taxa (including Ureaplasma and Aerococcus) were associated with HSV-2 in women. CONCLUSIONS We demonstrate that penile taxa are associated with HSV-2 in female partners, and vaginal taxa are associated with HSV-2 in male partners. Our findings suggest that couples-level joint consideration of genital microbiome and STI or related outcomes could lead to new avenues for prevention.