Autopsies carried out by scientists showed that the virus causing Covid-19 can be found throughout the entire body, including the eyes, and remain present for more than seven months.
A study published in the journal Nature describes how researchers did complete autopsies from April 2020 to March 2021 of 44 unvaccinated people with severe Covid-19. The median age was 62.5 years old, and 30% were female. Extensive brain sampling was done for 11 cases.
The National Institute of Health’s National Institute of Allergy and Infectious Diseases and Clinical Centre led the work, closely collaborating with National Cancer Institute (NCI) pathologists, four other NIH institutes, the University of Maryland, and Maryland health care facilities in Salisbury and Towson.
Due to its nature as a respiratory illness, the virus, clinically known as SARS-CoV-2, was most widespread in the respiratory system such as in the lungs. But it was also found in 79 other body locations, including the heart, kidneys, liver, muscles, nerves, reproductive tract, and eyes, reports Medscape.
The researchers, led by Dr Daniel Chertow, said their work shows the virus “is capable of infecting and replicating within the human brain”, and that it spreads via the blood early during infection, which “seeds the virus throughout the body after infection of the respiratory tract”.
The authors noted that while the virus was found outside the respiratory tract, they did not find signs of inflammation beyond the respiratory system.
The results will help narrow down treatments for long Covid, and particularly support the idea of using the antiviral drug Paxlovid to treat this condition, according to a blog post from the National Institute of Allergy and Infectious Diseases. A clinical trial is already under way examining the treatment, and results are expected in January 2024.
The Paxlovid trial, which begins this year, is part of the NIH-funded RECOVER project – Researching COVID to Enhance Recovery – and includes an extension of the autopsy work, according Dr Stephen Hewitt of NCI, who collaborated on the paper in Nature, and serves on a steering committee for the RECOVER project.
He said one branch of RECOVER includes tissue pathology studies, and obtaining material from autopsies is in progress; these autopsies include people who both were vaccinated and infected with variants of concern – data not available in the earlier study that Chertow’s group led.
“We’re hoping to replicate the data on viral persistence and study the relationship with long COVID,” Hewitt said, adding that the project is scheduled to last four years. “Less than a year in we have about 85 cases, and we are working to expand these efforts.”
Study details
SARS-CoV-2 infection and persistence in the human body and brain at autopsy
Sydney Stein, Sabrina Ramelli, Alison Grazioli, Joon-Yong Chung, NIH COVID-19 Autopsy Consortium, Daniel Chertow et al.
Published in Nature on 14 December 2022
Abstract
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 prolonged symptoms, termed post-acute sequelae of SARS-CoV-2. However, the burden of infection outside the respiratory tract and time to viral clearance are not well characterised, particularly in the brain. Here we carried out complete autopsies on 44 patients who died with 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 across the human body, including the brain, from acute infection to more than seven months following symptom onset. We show that SARS-CoV-2 is widely distributed, predominantly among patients who died with severe Covid-19, and that virus replication is present in multiple respiratory and non-respiratory tissues, including the brain, early in infection. Further, we detected persistent SARS-CoV-2 RNA in multiple anatomic sites, including throughout the brain, as late as 230 days after symptom onset in one case. Despite 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 indicate that in some patients SARS-CoV-2 can cause systemic infection and persist in the body for months.
NIH article – NIAID Pandemic Autopsy Study Fosters Long COVID Treatment Trial (Open access)
Medscape article – Autopsies Show COVID Virus Invades Entire Body (Open access)
See more from MedicalBrief archives:
Paxlovid as a treatment for long COVID
British man with long COVID finally cured of virus after 411 days
WHO estimates 17m long COVID cases in Europe and urges action
Scientists warn of hidden crisis as suicides potentially linked to long COVID
Long COVID impacts heart, lung and kidney – Scottish study