How coronavirus attacks the human body

Deborah Coughlin was neither short of breath nor coughing. In those first days after she became infected by the novel coronavirus, her fever never spiked above 100 degrees. It was vomiting and diarrhea that brought her to a Hartford, Conn., emergency room on May 1.

“You would have thought it was a stomach virus,” said her daughter, Catherina Coleman. “She was talking and walking and completely coherent.”

But even as Coughlin, 67, chatted with her daughters on her cellphone, the oxygen level in her blood dropped so low that most patients would be near death. She is on a ventilator and in critical condition at St. Francis Hospital, one more patient with a strange constellation of symptoms that physicians are racing to recognize, explain and treat.

“At the beginning, we didn’t know what we were dealing with,” said Valentin Fuster, physician-in-chief at Mount Sinai Hospital in New York City, the epicenter of the U.S. outbreak. “We were seeing patients dying in front of us. It was all of a sudden, you’re in a different ballgame, and you don’t know why.”

Today, there is widespread recognition the novel coronavirus is far more unpredictable than a simple respiratory virus. Often it attacks the lungs, but it can also strike anywhere from the brain to the toes. Many doctors are focused on treating the inflammatory reactions it triggers and its capacity to cause blood clots, even as they struggle to help patients breathe.

Learning about a new disease on the fly, with more than 78,000 U.S. deaths attributed to the pandemic, they have little solid research to guide them. The World Health Organization’s database already lists more than 14,600 papers on covid-19. Even the world’s premier public health agencies, including the Centers for Disease Control and Prevention, have constantly altered their advice to keep pace with new developments.

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“We don’t know why there are so many disease presentations,” said Angela Rasmussen, a virologist at the Center for Infection and Immunity at Columbia University’s Mailman School of Public Health. “Bottom line, this is just so new that there’s a lot we don’t know.”

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.

It mostly spares the young. Until it doesn’t: Last week, doctors warned of a rare inflammatory reaction with cardiac complications among children that may be connected to the virus. On Friday, New York Gov. Andrew M. Cuomo (D) announced 73 children had fallen severely ill in the state and a 5-year-old boy in New York City had become the first child to die of the syndrome. Two more children had succumbed as of Saturday.

That news has shaken many doctors, who felt they were finally grasping the full dimensions of the disease in adults. “We were all thinking this is a disease that kills old people, not kids,” Reich said.

Mount Sinai has treated five children with the condition. Reich said each started with gastrointestinal symptoms, which turned into inflammatory complications that caused very low blood pressure and expanded their blood vessels. This led to heart failure in the case of the first child who died.

“The pattern of disease was different than anything else with covid,” he said.

“We were all thinking this is a disease that kills old people, not kids,” said David Reich, president of Mount Sinai Hospital in Manhattan. (Jeenah Moon/Reuters)

Of the millions, perhaps billions, of coronaviruses, six were previously known to infect humans.

Four cause colds that spread easily each winter, barely noticed. Another was responsible for the outbreak of severe acute respiratory syndrome that killed 774 people in 2003. Yet another sparked the outbreak of Middle East respiratory syndrome in 2012, which kills 34 percent of the people who contract it. But few do.

SARS-CoV-2, the bad seed of the coronavirus family, is the seventh. It has managed to combine the infectiousness of its cold-causing cousins with some of the lethality of SARS and MERS. It can spread before people show symptoms of disease, making it difficult to control, especially without widespread and accurate testing. At the moment, social distancing is the only effective countermeasure.

It has infected 4 million people around the globe, killing more than 280,000, according to the Johns Hopkins University Coronavirus Resource Center. In the United States, 1.3 million have been infected and more than 78,000 have died.

Had SARS or MERS spread as widely as this virus, Rasmussen said, they might have shown the same capacity to attack beyond the lungs. But they were snuffed out quickly, leaving only a small