Once inside a human cell, the new coronavirus has a rare ability to silence alarms that would normally alert the immune system to mobilize antibodies and virus-killing cells, according to microbiologists at the Icahn School of Medicine at Mount Sinai, New York. To do so, it makes special proteins that interfere with the cell’s surveillance system, scientists at the University of Minnesota reported in May.
Doctors who first encountered it diagnosed it as a respiratory virus. They looked for symptoms of fever, cough and shortness of breath. But Covid-19 triggered bewildering complications.
People complained of nausea or diarrhea. Some had arrhythmias or even heart attacks. Some suffered kidney damage or liver failure. Some lost their sense of smell or taste. Other patients turned up at clinics with blood clots or swollen purple bumps on their toes.
In most countries where the virus triggered outbreaks, it sent people to the hospital with delirium, blackouts, brain inflammation or strokes.
“This virus is really diabolical, it came like a thief in the night with an insatiable appetite for victims to devour,” Dr. [Peter] Piot said. “It behaves unlike any other virus. It spreads through our respiratory system because there are receptors in our noses and throats—but then it goes through your entire body: blood vessels, the heart, every organ could be targeted. It’s crazy.”