Autopsies show the COVID-19 virus in the brain and elsewhere in the body

Abstract: Autopsy tissue samples from 44 people who died of COVID-19 showed that SAR-CoV-2, the virus responsible for the coronavirus, had spread through the body and into the brain, and traces of the virus persisted for 8 months.

Source: University of Minnesota

Analysis of tissue samples from the autopsies of 44 people who died of COVID-19 shows that the SAR-CoV-2 virus spread throughout the body – including the brain – and persisted for almost eight months.

The study was published in Nature.

Scientists from the National Institutes of Health (NIH) tested autopsy specimens that were performed from April 2020 to March 2021. They conducted extensive sampling of the nervous system, including the brain, in 11 patients.

RNA and live virus in various organs

All patients died of COVID-19, and no one was vaccinated. The blood plasma of 38 patients was positive for SARS-CoV-2, three were negative, and for the other 3 plasma was not available.

Thirty percent of the patients were women, and the average age was 62.5 years. Twenty-seven patients (61.4%) had three or more comorbidities. The mean interval from onset of symptoms to death was 18.5 days.

The analysis showed that SARS-CoV-2, as expected, primarily infected and damaged the airways and lung tissue. But the researchers also found viral RNA in 84 different body sites and body fluids, and in one case isolated viral RNA 230 days after the patient’s symptoms began.

The researchers detected SARS-CoV-2 RNA and protein in the hypothalamus and cerebellum of one patient and in the spinal cord and basal ganglia of two other patients. But they found little damage to brain tissue, “despite significant viral load.”

The researchers also isolated live SARS-CoV-2 virus from various tissues inside and outside the respiratory tract, including the brain, heart, lymph nodes, gastrointestinal tract, adrenal gland, and eye. They isolated the virus from 25 out of 55 tested samples (45%).

The authors wrote, “We demonstrated viral replication at multiple non-respiratory sites during the first two weeks after symptom onset.”

They add: “Our focus on short postmortem intervals, a comprehensive standardized approach to tissue collection, brain dissection before fixation, later tissue preservation for RNA and rapid freezing of fresh tissue allowed us to detect and quantify SARS-CoV-2 RNA levels with high sensitivity by [polymerase chain reaction] and [in situ hybridization]as well as isolate the virus in cell culture from multiple non-respiratory tissues including the brain, which are significant differences compared to other studies.”

Possible consequences of long-term COVID

Senior study author Daniel Chertow, MD, MPH, said in a statement to the NIH that, before the work, “SARS-CoV-2 was thought in the field to be predominantly a respiratory virus.”

Finding the presence of the virus throughout the body — and sharing those findings with colleagues a year ago — helped scientists investigate the link between widely infected body tissues and “long COVID,” or symptoms that persist for weeks and months after infection.

Part of the Paxlovid RECOVER trial expected to begin in 2023 involves expanding the autopsy work highlighted in Nature study, according to co-author Stephen Hewitt, MD, Ph.D., who is a member of the RECOVER project’s steering committee. Autopsies in the RECOVER trial include people who were vaccinated and infected with the worrisome variants—data that were not available in yesterday’s study.

“We hope to replicate the persistence data and study the relationship with long-term COVID,” Hewitt said. “In less than a year, we have about 85 cases and we are working to expand those efforts.”

About this news about COVID-19 and neurological research

Author: Jim Wappes
Source: University of Minnesota
Contact: Jim Wappes – University of Minnesota
Picture: The image is attributed to the researchers

Original research: Closed access.
“SARS-CoV-2 infection and persistence in the human body and brain at autopsy” Sydney R. Stein et al. Nature

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Abstract

SARS-CoV-2 infection and persistence in the human body and brain at autopsy

Coronavirus disease 2019 (COVID-19) is known to cause multi-organ dysfunction during acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with some patients experiencing long-lasting symptoms, called post-acute sequelae of SARS-CoV -a -2.

However, the burden of infection outside the respiratory tract and the time to viral clearance are not well described, particularly in the brain.

Here, we performed complete autopsies on 44 patients who died of COVID-19, with extensive sampling of the central nervous system in 11 of these patients, to map and quantify the distribution, replication, and cell type specificity of SARS-CoV-2 throughout the human body, including the brain , from acute infection to more than seven months after the onset of symptoms.

We show that SARS-CoV-2 is widely distributed, mainly among patients who have died of severe COVID-19 disease, and that viral replication is present in multiple respiratory and non-respiratory tissues, including the brain, early in the infection. Furthermore, we detected persistent SARS-CoV-2 RNA at multiple anatomical sites, including throughout the brain, as long as 230 days after symptom onset in one case.

Despite the extensive distribution of SARS-CoV-2 RNA throughout the body, we observed little evidence of inflammation or direct viral cytopathology outside the respiratory tract. Our data show that in some patients, SARS-CoV-2 can cause systemic infection and persist in the body for months.