A recent study has revealed that the Hepatitis E virus (HEV) might be sexually transmitted and linked to male infertility, sparking significant concern in the medical community.
Published in PLOS Pathogens, the research conducted by scientists at Ohio State University explores Hepatitis E's infectivity in pigs, aiming to draw parallels to human health.
Hepatitis E is a leading cause of acute viral liver infection worldwide, with an estimated 20 million infections annually.Image via CDC
The Threat of Hepatitis E
Hepatitis E is a leading cause of acute viral liver infection worldwide, with an estimated 20 million infections annually, resulting in around 44,000 deaths in 2015.
It is particularly prevalent in regions with poor sanitation, transmitted primarily via the fecal-oral route through contaminated water. While a vaccine exists in China, it is not yet available globally.
The study at hand focuses on the potential for the Hepatitis E virus to be sexually transmitted and its impact on male fertility. Researchers chose pigs for their study due to the similarity of their reproductive anatomy to humans. Pigs are also a natural host for HEV, making them an ideal model for this research.
Alarming Findings
The researchers found Hepatitis E virus proteins in the testis and HEV RNA in semen, indicating that the virus can be present in the male reproductive system. Notably, infectious Hepatitis E virus was discovered in mature sperm cells from infected pigs.
This presence affected the viability of the sperm, suggesting a potential link to infertility. "Our study is the first one demonstrating this association of hepatitis E virus with the sperm cell," said Kush Yadav, the study's first author.
Using fluorescence microscopy, the team detected viral particles associated with at least 19% of sperm cells in infected pigs. This finding suggests that sperm might act as a carrier for the virus, although whether HEV can complete its replication cycle in the sperm head remains unknown. "We can't say they're sitting on the outside or inside the sperm cells," Yadav explained.
"We don't know if the hepatitis E virus can actually complete a replication cycle in the sperm head, so we're thinking sperm is more of a carrier than a susceptible cell."
Implications for Human Health: What You Need to Know
The study's implications are significant, particularly for understanding unexplained male infertility. Scott Kenney, the senior study author, stressed that a large portion of documented male infertility cases have unknown causes and suggested increased screening for hepatitis E virus as a potential factor.
The findings also suggest a need for screening the sexual partners of pregnant women who test positive for Hepatitis E virus, as sexual transmission could contribute to the high mortality rates seen in pregnant women with Hepatitis E virus.
The study also has implications for the swine industry, where most commercial pig litters are produced via artificial insemination. The presence of the Hepatitis E virus in donor sperm could affect reproductive efficiency, prompting consideration of cost-effective screening or vaccination to reduce the virus's introduction into new pig herds.
