As the coronavirus pandemic spread around the world this year at such a devastating level, many of us asked similar questions. How is the virus spread? How can I protect myself from infection?
The truth is we are still looking at how SARS-CoV-2 works. Official CDC guidelines show that the main way the virus is spread is through respiratory droplets or droplets, which are sprayed from the mouth or nose of an infected person, and then inhaled by someone else.
But that’s not the only way viruses circulate. Similar contagious droplets and particles can fall to the surface and be transmitted when touched – meaning you can be infected if you touch something with virus particles, the CDC says. on it, and then touch your mouth, nose, or eyes, the CDC says.
Although this general advice is repeated by health authorities around the world, there̵7;s still a lot we don’t know about how coronaviruses can enter the body through the eye, although scientists they considered it “biologically plausible”.
However, new evidence suggests that at least some eyes are in fact resistant to SARS-CoV-2 – even if the eyes are sensitive to other viruses.
In a new study, researchers at Washington University in St. Petersburg Louis found that the cornea – the transparent dome in the front of the eye that covers the iris and pupils – appears to be able to resist coronavirus infection in experiments, although they were eager. stress the findings are only preliminary.
“Our findings do not prove that all corneas are resistant to drugs,” said the molecular microbiologist Jonathan J. Miner, the first author of the study.
“But every donor cornea we have tested is resistant to the new coronavirus. It is still possible that there are a small number of people who may have corneas that support viral growth, but not. Which cornea we study supports the development of SARS-CoV-2. “
In experiments using corneal tissue from 25 human donors and mouse corneas, researchers exposed eye tissue to three distinct viruses: SARS-CoV-2, Zika virus. and the herpes simplex virus 1 (HSV-1, the virus that causes herpes).
In the human corneal samples tested (which also contains some conjunctival tissue, the membrane covering the rest of the eye), the experiment shows that the herpes and Zika viruses can multiply in tissue – but tests Test showed no evidence of SARS-CoV-2 Copy.
Author and ophthalmologist Rajendra S. Apte said: “The cornea and conjunctiva are known to have receptors for the new coronavirus, but in our studies we found that this virus does not multiply in the cornea.
“Our data shows that the new coronavirus doesn’t seem to be able to penetrate the cornea.”
As for how the human cornea and conjunctiva may be able to fight SARS-CoV-2, the team is not entirely sure. A potential molecular inhibitor of the virus in the eye – called interferon lambda – can inhibit the growth of the virus in the human cornea to HSV-1 and Zika viruses, but blocking the protein does not appear to increase the regeneration of SARS-CoV-2.
Needless to go, the researchers’ best prediction now is that the coronavirus resistance of the human cornea is “likely to be regulated by a separate antiviral pathway”. We still don’t know what that path is, and the team says more research is needed to confirm these findings.
In other words, health professionals should not have removed their protective goggles, and until we know otherwise, no one should assume that coronavirus cannot enter the body through the eyes, even though the cornea seems to have resistance.
“It is important to respect the capabilities of the virus and take the appropriate precautions,” Miner said.
“We may know that blindness is not needed to protect against infection in the general community, but our studies are really just the beginning.”
The findings are reported in Mobile Reporting.