Implications of RNA Viruses in the Male Reproductive Tract: An Outlook on SARS-CoV-2.

Mohammad Ishraq Zafar,Honggang Li,Jiangyu Yu

doi:10.3389/fmicb.2021.783963

Abstract

Emerging viral infections continuously pose a threat to human wellbeing. Several RNA viruses have managed to establish access to the male reproductive tract and persist in human semen. The sexual transmission of the virus is of critical public concern. The epidemiological inferences are essential to understand its complexity, particularly the probability of viral transmission from asymptomatic patients or those in the incubation period or from the patient who was previously infected and now fully recovered. From the clinical perspective, negative impacts in the male reproductive tract associated with RNA virus infection have been described, including orchitis, epididymitis, impaired spermatogenesis, and a decrease in sperm quality, which can affect male fertility at different time intervals. The disruption of anatomical barriers due to inflammatory responses might enable the viral invasion into the testis, and the immune privilege status of testes might facilitate a sustained persistence of the virus in the semen. In this review, the current knowledge about other RNA viruses that affect male reproductive health provides the framework to discuss the impact of the SARS-CoV-2 pandemic. The molecular mechanisms, sexual transmission, and viral impacts for mumps, HIV, Zika, and Ebola viruses are explored. We discuss the currently available information on the impact of SARS-CoV-2 and its sequelae in the male reproductive tract, particularly regarding presence in semen, its impact on sexual organs, and sperm quality. To date, no sexual transmission of SARS-CoV-2 has been reported, whereas the identification of viral particles in semen remains conflicting. In the purview of the earlier conducted analyses, it is essential to investigate further the long-term health impacts of SARS-CoV-2 on the male reproductive tract.

Highlights

The global pandemic caused by the outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Wang C. et al, 2020; Zhou P. et al, 2020) has caused 250 million infections and 5 million deaths worldwide1
Transmembrane serine protease 2 (TMPRSS2) enhances angiotensin-converting enzyme 2 (ACE2)-mediated virus entry (Walls et al, 2020). Both ACE2 and TMPRSS2 proteins are expressed in the testis and male reproductive tract (Hamming et al, 2004; Jia et al, 2005; Hikmet et al, 2020; Lee et al, 2020; Song H. et al, 2020; Wang and Xu, 2020)
The current review aims to consolidate and discuss the current information concerning the SARS CoV-2 virus’ impact on the male reproductive tract, shed light on viral presence in semen, and emphasize the challenges posed to male reproductive health during and after the pandemic

Summary

Introduction

The global pandemic caused by the outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Wang C. et al, 2020; Zhou P. et al, 2020) has caused 250 million infections and 5 million deaths worldwide1. Seminal vesicles and prostate are generally overlooked when viral infection of the male reproductive tract is studied, it has been demonstrated that RNA viruses can infect those organs and may contribute to viral shedding in semen.

Results

Conclusion