World Health Organization recently have been conducting studies that show even people who haven’t had symptoms of Zika infection might be able to infect other sexually- and last week, the first case was reported. After injecting the test subjects with Zika, the researchers learned that the virus continued to “live in the eyes for seven days”, according to the Eurekalert press release.
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This discovery had raised the possibility that the infection may spread through tears.
A strain of Zika now circulating in Latin America has been proven to cause brain and head abnormalities in newborns.
Scientists discovered earlier this year that the virus can live longer than previously thought in a person’s blood or bodily fluids, which is why people are now being advised to practice safe sex or abstain completely for six months.
One third of babies infected with Zika in utero have eye disease such as inflammation of the optic nerve, retinal damage or blindness, the researchers said. In adults, the virus can lead to conjunctivitis, which is characterized by redness and itchiness, and uveitis in rarer cases.
The study out of Washington University could help understand how the mosquito-borne virus can cause eye disease.
Genetic material from the Zika virus is present in the tears of infected mice, which suggests the virus may linger in the eyes, researchers say.
In adult mice bred to be susceptible to Zika, any signs of eye disease appeared within 7 days after being injected with the virus.
The connection between Zika and microcephaly first came to light last autumn in Brazil, which has since confirmed more than 1,800 cases of microcephaly.
Last week, WHO declared that the continued spread of Zika – it has now infected more than 70 countries and territories – remains a global health emergency. The update comes after Zika was found in the semen of a man six months after he came into contact with the virus.
According to Jonathan J. Miner, M.D., Ph.D., while the mouse tears did not harbor the live virus, it doesn’t mean that it would be the same in humans.
The eyes, Diamond said, are considered an “immune-privileged site”, meaning the immune system is less active there, so as not to accidently damage delicate eye tissue.
State and school district officials here say they’re armed with federal guidance about how to handle Zika if it pops up among students, but so far it hasn’t been an issue.
While experts agree mosquitoes remain the main concern, recent studies indicate that women have been infected with the virus more often than men have, possibly because of sexual transmission. “If you know you have virus replicating in the eye, you can just give the drug locally and measure any change in viral replication”.
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As of August 26, a total of 17 studies have been published on the sexual transmission of the Zika virus.
