More than four months of clinical experience across Asia, Europe and North America has shown the pathogen does much more than invade the lungs. “No one was expecting a disease that would not fit the pattern of pneumonia and respiratory illness,” said David Reich, a cardiac anesthesiologist and president of Mount Sinai Hospital in New York City.

It attacks the heart, weakening its muscles and disrupting its critical rhythm. It savages kidneys so badly some hospitals have run short of dialysis equipment. It crawls along the nervous system, destroying taste and smell and occasionally reaching the brain. It creates blood clots that can kill with sudden efficiency and inflames blood vessels throughout the body.

It can begin with a few symptoms or none at all, then days later, squeeze the air out of the lungs without warning. It picks on the elderly, people weakened by previous disease, and, disproportionately, the obese. It harms men more than women, but there are also signs it complicates pregnancies.