COVID-19 can ‘hide’ in brain and cause relapses, study finds

A new study suggests that the coronavirus responsible for COVID-19 could lurk in the brains of infected people and cause relapses in patients who appeared to be recovering.

In a study published Tuesday by the journal Virus, researchers at Georgia State University found that mice infected with the virus through their nasal passages developed severe illness due to a brain infection even after the virus left their lungs. Lead researcher and co-author of the study, Mukesh Kumar, suggested the findings may explain why human patients who seem to almost recover from the disease sometimes relapse quickly and die.

“The brain is one of the regions where the virus likes to hide,” Kumar said in a press release. “That’s why we see serious illnesses and all these multiple symptoms like heart disease, stroke and all those long haul hauls with loss of smell, loss of taste … It all has to do with the brain instead. than with the lungs. . “

The study found that the virus was localized in the brains of mice at a level 1,000 times higher than in any other area of ​​the body. While the levels of the virus located in the lungs began to decline after three days of infection, the virus remained at high levels in the brain on the fifth and sixth days, when the course of the disease worsened.

“Our thought that this is more of a respiratory disease is not necessarily true,” Kumar said. “Once it infects the brain, it can affect anything because the brain controls your lungs, heart, everything. The brain is a very sensitive organ. It is the central processor of everything.”

In addition to COVID-19, Kumar suggests that the coronavirus reaching the brain could make patients vulnerable to other serious health conditions in the future, including neurological conditions such as Parkinson’s disease and multiple sclerosis, as well as general cognitive decline and autoimmune diseases.

“It’s scary,” he says. “A lot of people think they’ve had COVID and they’ve recovered and now they’re out of the woods. Now I feel like that will never be true. You may never be out of the woods. “

Neurological symptoms are known to be relatively common in people with COVID-19. However, while many studies have suggested that the brain of mice is susceptible to infection with the virus, the research has not produced conclusive evidence to support the idea that the virus infects and concentrates in the human brain. . Neurological symptoms can be caused by an immune response rather than a direct brain infection.

A blog post written by National Institutes of Health Director Dr Francis Collins last week detailed a recent study by the National Institute of Neurological Disorders and Stroke that found brain damage in tissue samples from 19 people died from COVID-19 but no evidence that the virus had infected brain tissue itself.

“The results are particularly intriguing because it has been suggested, based on studies in mice, that SARS-CoV-2 could cross the blood-brain barrier and invade the brain,” Collins wrote, before noting that a another study, published in the Journal of Experimental Medicine, had found evidence of the virus in the brains of three people who died of complications from COVID-19.

“Obviously, more research is needed, ” Collins added. “As we learn more about the many ways COVID-19 wreaks havoc on the body, understanding neurological symptoms will be essential in helping people. “