Study Links HSV-1 Infection Through the Nose to Long-Term Neurological Issues

Herpes simplex virus-1 (HSV-1), known for causing blisters and sores, can also lead to severe neurological and ocular complications. Researchers at the University of Illinois Chicago (UIC) have discovered that intranasal HSV-1 infection may result in long-term anxiety, motor impairment, and cognitive deficits, highlighting the need for better prevention and treatment strategies for this widespread virus. 

The study, led by Deepak Shukla, focused on how HSV-1 enters the body through the nasal cavity, providing direct access to the nervous system. Shukla explained, “If an infected individual is shedding virus via tears, it could reach the nasal cavity, where it could go more directly to the brain. I think it’s underdiagnosed and understudied, but the neurological consequences, we believe, are much more severe than you would normally see with fever blisters or ocular infection.”  

Using animal models, the team observed significant inflammation and neuronal damage shortly after intranasal infection. Over several months—equivalent to decades in human life—infected animals showed impaired motor coordination, memory deficits, and increased anxiety-like behavior compared to controls. “There is definitely nerve damage if you take the intranasal route, and the effects are long-term, which is alarming,” Shukla noted.

The study also examined heparanase, a cellular enzyme previously linked to HSV-1 reinfection. Animals lacking heparanase did not exhibit the same neurobehavioral symptoms as controls, suggesting the enzyme plays a role in mediating brain damage caused by the virus. “These insights open the door to potential therapeutic approaches,” said Hemant Borase, first author of the study published in mBio.

With nearly two-thirds of the global population carrying HSV-1, co-author Chandrashekhar Patil emphasized the importance of raising awareness: “The virus reactivates throughout life; it’s a lifelong infection.”