Human eye tissue appears to be resistant to SARS-CoV-2

A new study investigated whether infection with Sars-CoV-2, the virus that causes Covid-19, could enter the body through corneal tissue.

It’s been almost a year since the pandemic happened, and I’m always learning how Covid-19 spreads. Epidemics believe that the main way the virus is transmitted is through respiratory droplets or small particles that are released when an infected person coughs, sneezes, talks, or breathes. However, in the early days of the pandemic, governments around the world believed that most of the infection was caused by touching the contaminated surface and then touching their face.

Centers for Disease Control and Prevention (CDC) Note The droplet “can land on a surface or object and move by touching it. A person touches a surface or object to which the virus is attached and then touches his or her mouth, nose, or eyes. Can be infected with Covid-19. ” The CDC currently states that “spreading by touching the surface is not considered to be the main method of spreading the virus,” but it is still considered to be a known method of infection.

It has been suggested that the virus can infect as well as through the mouth and nose. Enter through the eyes.. Patients with this disease often get conjunctivitis. Conjunctivitis can be caused by viruses and other mechanisms and is being investigated by a team of researchers at Washington University in St. Louis School of Medicine.

Report in the journal Cell reportsThe team wanted to see if their eyes would be the gateway to Sars-CoV-2, given that the Zika virus had previously been shown to shed tears. They exposed human (from donors) and mouse corneas (iris, pupils, transparent anterior part of the eye covering the anterior chamber) to new coronaviruses, Zika fever, and herpes to see if they could replicate there.

Herpes and Zika fever could reproduce in the cornea, but Sars-CoV-2 did not.

“The cornea and conjunctiva are known to have new receptors for the coronavirus, but our study found that the virus did not replicate in the cornea,” said senior author and ophthalmologist Rajendra. S. Apte statement.. “Our data suggest that the new coronavirus does not appear to be able to invade the cornea.”

They have found important substances in their eyes that may inhibit or promote viral replication, including what is called interferon lambda. It was found to interfere with the efficient growth of both Zika and herpes, but had no effect on Sars-CoV-2, as it could not replicate primarily in the cornea.

The news is welcome, but the team is keen to provide a word of caution. They state that they have not yet determined whether other tissues in and around the cornea, such as the lacrimal duct and conjunctiva, are vulnerable to the coronavirus. Also, it is not clear whether the symptoms such as conjunctivitis are due to the virus or secondary inflammation when the body’s defenses are low.

“Our findings do not prove that all corneas are resistant,” said lead author Jonathan J. Minor. “But all the donor corneas we tested were resistant to the new coronavirus. It is possible that some people still have corneas that support the growth of the virus, but we investigated. None of the corneas supported SARS-CoV-2 proliferation. “

The team warned that their findings are still preliminary and that people should take all precautions against the virus, including the use of eyeglasses in hospitals, until we know more. ..

“You may find that the general public does not need an eye cover to prevent infection, but our research is really just the beginning. A better understanding of all potential pathways for SARS. Therefore, larger clinical studies are needed. CoV-2 infection, including eyes. “