Human papillomavirus seminal carriage alters virome diversity and male fertility: a case-control study

A link between idiopathic male infertility and viral infections exhibiting seminal carriage has emerged recently. In this respect, human papillomavirus (HPV) appears to be the most prevalent sexually transmitted agent worldwide. The viruses present in the genital environment comprise the genital virome. HPV infection reportedly disrupts homeostasis of the virome in women but this topic has not previously been studied in men.

This was a retrospective study of males attending the fertility clinic at Amiens University Medical Center (Amiens, France). Men with a multiple-type HPV infection in the sperm (n = 15) were considered to be cases, and men with no detectable HPV in the sperm were considered to be controls (n = 13). The molecular virome in cases and controls was described via metagenomic next-generation sequencing. The cases and controls were compared with regard to genomic, clinical and sperm-related characteristics.

The seminal virome analysis revealed the predominance of Papillomaviridae in cases (63.4%). Other virus families found in both groups (albeit with lower proportions of reads in cases than in controls) were Herpesviridae (6.9% vs. 40.5%, respectively), Polyomaviridae (11.3% vs. 17.8%, respectively), and other viral sequences (18.4% vs. 40%, respectively). There was no difference in viral diversity between the two groups (p = 0.0692). Viral diversity was correlated with the semen sample volume, progressive sperm motility, total motility, and sperm vitality in cases but not in controls. Univariate and multivariate comparative analyses did not reveal significant differences in sperm parameters between cases and controls.

The male seminal virome mainly comprises viruses from the Papillomaviridae, Herpesviridae and Polyomaviridae families. The correlation between viral diversity and sperm parameters in HPV-positive patients suggests that HPV-specific interactions within the seminal virome are responsible for variations in sperm parameters. Hence, alterations in the seminal virome (due mostly to HPV infection) might impact sperm parameters and thus male fertility.