The virus that causes COVID-19 can spread to a patient’s heart and brain days after infection — and survive for months in organs, according to a new study that may shed light on the so-called “long COVID.”
Scientists at the US National Institutes of Health in Maryland studied tissues taken from 44 people who had died after contracting the illness during the first year of the pandemic in the US, Bloomberg News reported.
They discovered SARS-CoV-2 RNA in various parts of the body — including the heart and brain — for as long as 230 days after the onset of symptoms, according to the news outlet.
The delayed viral clearance was cited as a possible contributor to long-haul COVID, also called “post-acute sequelae of SARS-CoV-2,” which is defined by the Centers for Disease Control and Prevention as a range of long-lasting symptoms among patients.
The study is under review by independent scientists for publication in the journal Nature.
“This is remarkably important work,” Ziyad Al-Aly, director of the clinical epidemiology center at the Veterans Affairs St. Louis Health Care System in Missouri, told Bloomberg.
“For a long time now, we have been scratching our heads and asking why long COVID seems to affect so many organ systems,” said Al-Aly, who has led separate studies into the long-term effects of the illness.
“This paper sheds some light, and may help explain why long COVID can occur even in people who had mild or asymptomatic acute disease,” he added.
Scientists have cited evidence both for and against the likelihood that the deadly bug infects cells outside the lungs and respiratory tract, Bloomberg noted.
“Our results collectively show that while 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,” said the team, led by Daniel Chertow, who runs the NIH’s emerging pathogens section.
Raina MacIntyre, professor of global biosecurity at the University of New South Wales in Sydney, Australia, told Bloomberg that the research “provides a warning about being blasé about mass infection in children and adults.”
MacIntyre, who was not involved in the study, told the outlet: “We don’t yet know what burden of chronic illness will result in years to come.
“Will we see young-onset cardiac failure in survivors, or early onset dementia? These are unanswered questions which call for a precautionary public health approach to mitigation of the spread of this virus,” she added.
The NIH scientists suggested that infection of the pulmonary system may cause an early “viremic” phase, in which the coronavirus is present in the bloodstream throughout the body.
MacIntyre told Bloomberg that the findings also support previous research that shows that the virus directly kills heart muscle cells — and that surviving patients suffer cognitive deficits.
The virus was detected in the brains of all six patients who died over a month after they developed symptoms, as well as in most areas studied in the brains of five others, including one who died 230 days after the onset of symptoms, the outlet said.
Al-Aly said the focus on multiple brain areas is particularly helpful.
“It can help us understand the neurocognitive decline or ‘brain fog’ and other neuropsychiatric manifestations of long Covid,” he told Bloomberg.
“We need to start thinking of SARS-CoV-2 as a systemic virus that may clear in some people, but in others may persist for weeks or months and produce long Covid — a multifaceted systemic disorder,” he added.