A recent study published in PLOS Pathogens has raised concerns in the medical community by suggesting that the Hepatitis E virus (HEV) may be sexually transmitted and linked to male infertility. Conducted by scientists at Ohio State University, the research focused on pigs due to the similarity of their reproductive anatomy to humans and their status as a natural host for HEV. The study found HEV proteins in the testis and HEV RNA in semen, with infectious HEV detected in mature sperm cells. This presence impacted sperm viability, indicating a potential link to infertility. Lead researcher highlighted that this is the first study to demonstrate HEV's association with sperm cells, although it remains unclear whether the virus can complete its replication cycle within these cells.

Hepatitis E is a significant cause of acute viral liver infection globally, with around 20 million infections annually and approximately 44,000 deaths in 2015. It is mainly transmitted through contaminated water in regions with poor sanitation, and though a vaccine exists in China, it is not available worldwide. The study's findings suggest that sperm might act as a carrier for the virus, raising questions about unexplained male infertility and the potential need for increased screening for HEV in such cases. The research also implies that screening sexual partners of pregnant women who test positive for HEV could be crucial, as sexual transmission might contribute to high mortality rates in pregnant women with the virus.

The implications extend to the swine industry, where artificial insemination is common. The presence of HEV in donor sperm could affect reproductive efficiency, suggesting a need for cost-effective screening or vaccination to prevent the virus's introduction into new pig herds. These findings underscore the importance of further research into HEV's transmission routes and its impact on both human and animal health.