As new COVID-19 cases continue to set daily records nationally, the illness appears to have become less deadly than it was in the spring, according to data and anecdotes in Massachusetts and across the nation.
It’s not clear why — or whether the death rate will spike up again. But local doctors theorize that a higher percentage of infections among younger people, improved understanding of how to treat the illness, and less stress on hospital systems have contributed to the change.
Make no mistake, the sheer number of deaths has been increasing because more people are getting infected, with more than 1,000 deaths per day nationally and about 20 per day in Massachusetts.
But among those who fall ill with COVID-19, the proportion who die has been shrinking in recent weeks.
“Not as many people are critically ill,” said Dr. Paul Sax, clinical director of the Division of Infectious Diseases at Brigham and Women’s Hospital. “When I talk to my colleagues around town, they are experiencing the same thing.”
Nationwide, COVID-19 cases increased 57 percent over the past two weeks, and deaths have increased 12 percent in that time, according to calculations by The New York Times. In Massachusetts there has been a seven-day average of 1,571 cases per day, an increase of 68 percent over the average two weeks ago, while deaths increased 19 percent, according to the data.
Dr. Paul Biddinger, director for emergency preparedness at the Mass General Brigham hospital group, said that the death rate among COVID-19 patients has fallen by as much as a third to a half in his organization.
“We don’t know whether this decrease in the death rate will be sustained,” Biddinger said.
Typically, two to four weeks after a rise in infections among the young, the case count similarly rises in older people after the virus spreads, he said. And older people are more likely to die from the coronavirus.
“There’s no question we are better at treating COVID now than we were at the beginning,” Biddinger said. “This still is a very serious illness that can put even young people in the ICU and threaten their lives.”
Still, amid the apprehension as they confront the steady increase in cases since September, local doctors say they feel better prepared than in the spring to handle what comes their way.
At the start of the pandemic, no one knew what COVID-19 could do. Now doctors, nurses, and respiratory therapists are acquainted with its tricks and better able to manage its course.
“There is a greater comfort level in managing the patients,” said Dr. Michael H. Ieong, medical director of Boston Medical Center’s medical intensive care unit.
That has led to delaying and possibly reducing the use of ventilators. In the spring, doctors feared that a sudden respiratory failure would require forcing a tube down a patient’s throat on an emergency basis, risking infecting the staff. So they would intubate early to avoid that possibility, Ieong said.
Now, doctors have “a better understanding of how the disease progresses and how to tell when it’s about to take a turn to the worse,” he said. Many patients can recover by receiving supplemental oxygen while lying on their stomach to ease breathing, and thus can avoid the travails of mechanical ventilation, he said.
Additionally, two drugs have been approved to treat COVID-19. Remdesivir, an antiviral, was shown to shorten the length of hospital stays by a few days, but it’s not clear whether it saves lives. The other drug, the steroid dexamethasone, was found in studies to reduce mortality. If that result is borne out with wider use, this drug may also contribute to lower death rates.
“A smaller percentage of people admitted to the ICU will die, because dexamethasone and other steroids seem to have an effect on mortality,” said Dr. Nicholas A. Smyrnios, medical director of the medical intensive care units at UMass Memorial Medical Center. But if a large number of people are infected, he said, a smaller percentage would still amount to many deaths.
In addition to improved medical knowledge, hospitals also have experience managing a crush of severely ill patients.
“We have a better sense, an institutional memory, of how to handle the surge, how to operationalize our resources,” said Dr. George A. Alba a critical care physician and associate director of the Coronavirus Recovery Clinic at Massachusetts General Hospital.
Doctors also pointed to another phenomenon that could be affecting the death rate. In the early days of the pandemic, people who tested positive or had early symptoms were advised to go home and come back only if they got sicker.
“People delayed coming to the hospital until they were really quite critically ill,” said Sax, of Brigham and Women’s. “It wasn’t uncommon for them to come to the ER immediately needing intubation.”
Today people seek care earlier in the course of illness. Many have even purchased small devices to measure their blood oxygen levels at home, signaling breathing difficulties that may not otherwise be obvious.
Another life-saving factor: Nursing homes have improved testing and infection control. In the spring, 60 percent of the COVID-19 deaths in Massachusetts occurred among nursing home residents.
Ieong, of Boston Medical Center, said that multiple patients from the same facility would sometimes show up at the hospital, but that hasn’t happened as much recently. “The precautions and awareness and testing are much better,” he said.
Sax pointed to another theory worth considering: “Whenever a disease enters a community for the first time it takes as its victims the most vulnerable and susceptible,” he said. Those surviving until the second wave may have better defenses.
A recent study of a hospital system in New York City found that hospitalized patients of all ages were less likely to die as the months went by. The chances of dying dropped from 25.6 percent in March to 7.6 percent in August.
But many people who survive COVID-19 have long-lasting symptoms leaving them unable to work for weeks, months, or perhaps forever.
And the pandemic is far from over. “The summer was in some ways a blissful respite from what’s going to be a tough time for us over the next few months,” Sax said.
The doctors agreed that what happens next will be determined less by the progress of medical science than by the choices individuals make — whether people wear masks, stay physically apart, avoid large gatherings, and otherwise heed public health advice.
"The most important thing we can do is try to prevent infection in the first place,” Biddinger said.