Saguna Verma

One of the newest, and potentially most worrisome, ways the Zika virus can spread is through unprotected sex. A University of Hawaiʻi at Mānoa scientist Saguna Verma has received the first U.S. Zika-response funding in Hawaiʻi to research how the Zika virus infection in men makes them susceptible to transmit the virus to their sexual partners, even though they may appear symptom-free.

“Clinical data shows that infectious Zika virus can be sexually transmitted by men long after the virus is cleared from their blood,” said Verma, an associate professor of tropical medicine with the John A. Burns School of Medicine. She believes Zika virus hides within specific cells unique to the testes, silently prolonging the infection.

Verma and her partners will work with human cells that form a blood-testes barrier. Normally, a blood-testes barrier protects the delicate germ cells from infection and resulting “immune attack” by the immune cells from the blood. They intend to demonstrate the extraordinary way by which the virus penetrates this barrier.

“We believe the Zika virus infects cells of the blood-testes barrier and induces inflammation. This response may trigger the disruption of the blood-testes barrier and allow the virus to eventually enter the inner compartment of the testes and establish persistent infection in the germ cells,” said Verma. “We have standardized an in vitro blood-testes barrier model that will be used as an innovative tool to address this study.”

Ultimately if the mechanism by which the Zika virus enters and remains persistent in the testes for several months is discovered, Verma wants to unlock a way for antiviral medicines to be used to clear Zika virus from the testes and being spread through sex.

“This tug of war between the mankind versus pathogen inspires me. The idea that new host or virus players continue to evolve in the microscopic battle between re-emerging viruses and human immune system fascinates me,” Verma said.

The grant was awarded by the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.

For more information, read the John A. Burns School of Medicine news story.

—By Tina Shelton