Researchers from the Washington University School of Medicine in St. Louis have discovered Zika virus can live in the eye and have found genetic markers from the disease in tears.
This may reveal why some Zika patients develop eye disease that can include permanent vision loss from the condition.
The study, published on Tuesday in Cell Reports, confirms Zika can travel to the eye, but how it happens is still a question. It does raise the possibility of infection through contact of tears from those infected with Zika. Further, the tears contained genetic material from the disease, but not the infectious virus 28 days after infection.
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The eye might be a reservoir for the virus, according to the Michael S. Diamond, MD, the Herbert S. Gasser Professor of Medicine and one author of the study.
"We need to consider whether people with Zika have infectious virus in their eyes and how long it actually persists," Diamond said.
A third of infants infected with Zika in utero demonstrate eye disease like optic nerve inflammation, retinal damage or blindness. In adults, Zika can cause conjunctivitis and in rare cases uveitis.
The researchers studied the effects of the virus in the eyes of mouse fetuses, newborns and adults. Next, they plan to test Zika patients to determine if the virus persists in the cornea or other eye compartments, which may reveal if Zika can be transmitted through the cornea.
"Even though we didn't find live virus in mouse tears that doesn't mean it couldn't be infectious in humans," Jonathan J. Miner, MD, the study's lead author, said in a statement. "There could be a window of time when tears are highly infectious and people are coming in contact with it and able to spread it."
The discovery comes on the heels of a Senate gridlock on Tuesday for a bill that would fund a public response to Zika, which failed to garner the 60 votes needed to advance.
Democrats say they blocked the bill as Republicans added a provision to prevent Planned Parenthood funding, CNN reported.
Twitter: @JessieFDavis
Email the writer: jessica.davis@himssmedia.com
