How does coronavirus kill? Clinicians trace a ferocious rampage through the body, from brain to toes
As the number of confirmed cases of COVID-19 surges past 2.2 million globally and deaths surpass 150,000, clinicians and pathologists are struggling to understand the damage wrought by the coronavirus as it tears through the body. They are realizing that although the lungs are ground zero, its reach can extend to many organs including the heart and blood vessels, kidneys, gut, and brain.
“[The disease] can attack almost anything in the body with devastating consequences,” says cardiologist Harlan Krumholz of Yale University and Yale-New Haven Hospital, who is leading multiple efforts to gather clinical data on COVID-19. “Its ferocity is breathtaking and humbling.
If the immune system doesn’t beat back SARS-CoV-2 during this initial phase, the virus then marches down the windpipe to attack the lungs, where it can turn deadly. The thinner, distant branches of the lung’s respiratory tree end in tiny air sacs called alveoli, each lined by a single layer of cells that are also rich in ACE2 receptors.
Striking the heart
In Brescia, Italy, a 53-year-old woman walked into the emergency room of her local hospital with all the classic symptoms of a heart attack, including telltale signs in her electrocardiogram and high levels of a blood marker suggesting damaged cardiac muscles. Further tests showed cardiac swelling and scarring, and a left ventricle—normally the powerhouse chamber of the heart—so weak that it could only pump one-third its normal amount of blood. But when doctors injected dye in the coronary arteries, looking for the blockage that signifies a heart attack, they found none. Another test revealed why: The woman had COVID-19.
Buffeting the brain
Another striking set of symptoms in COVID-19 patients centers on the brain and central nervous system. Frontera says neurologists are needed to assess 5% to 10% of coronavirus patients at her hospital. But she says that “is probably a gross underestimate” of the number whose brains are struggling, especially because many are sedated and on ventilators.
Reaching the gut
In early March, a 71-year-old Michigan woman returned from a Nile River cruise with bloody diarrhea, vomiting, and abdominal pain. Initially doctors suspected she had a common stomach bug, such as Salmonella. But after she developed a cough, doctors took a nasal swab and found her positive for the novel coronavirus. A stool sample positive for viral RNA, as well as signs of colon injury seen in an endoscopy, pointed to a gastrointestinal (GI) infection with the coronavirus, according to a paper posted online in The American Journal of Gastroenterology (AJG).