Study reveals how Covid affects the brain

The SARS-CoV-2 virus that causes Covid-19 can within days move from the respiratory system into the brain, heart, and nearly every organ system in the body, and stay there for months, a new study says.

A team from the US National Institutes of Health (NIH) described their research as the “most comprehensive analysis” to date of how the virus spreads through the human body. The results were published online on Saturday in a manuscript, which was submitted under review in the Nature journal.

The scientists based their findings on autopsies of 44 patients who died after contracting Covid. The autopsies were performed between April 26, 2020 and March 2, 2021.

"Our results collectively show while that the highest burden of SARS-CoV-2 is in the airways and lung, the virus can disseminate early during infection and infect cells throughout the entire body, including widely throughout the brain."

The viral RNA was “widely distributed” even among patients who died with asymptomatic or mild cases of Covid, the researcher wrote. In some instances, the virus stayed in “regions throughout the brain” for up to 230 days following symptom onset.

Ziyad Al-Aly, the director of the clinical epidemiology center at the Veterans Affairs St. Louis Health Care System in Missouri, told Bloomberg the study may provide an answer to why some patients suffer from so-called ‘long Covid’, when symptoms stay persistent for months.

“For a long time now, we have been scratching our heads and asking why long Covid seems to affect so many organ systems. This paper sheds some light, and may help explain why long Covid can occur even in people who had mild or asymptomatic acute disease,” Al-Aly said.