What we initially got wrong about COVID-19
A lot of our early assumptions about the novel coronavirus have flip-flopped.
This is normal. That’s how science works — it’s a process of being less and less wrong over time. COVID-19 is new, so there’s lots of uncertainty. And the pandemic’s size and scale caught us by surprise. As we learn more, our understanding of the virus continues to change.
Here’s what we now know:
Masks are useful after all
Were you dubious about the U.S. Centers for Disease Control’s early assertion that mask “leakage” meant that it wouldn’t protect you from a virus? Join the crowd.
The CDC since has reversed its position. And an influential study in the Annals of Internal Medicine — which concluded that masks don’t effectively stop virus-laden droplets — was retracted due to statistical problems.
Now we wear them everywhere — indeed, they’re often required. While masks don’t offer perfect protection, any kind of impediment is better than nothing. And if you’re infected, a mask can help keep you from spreading the virus to others.
Don’t just blame China
To be sure, the crisis first emerged in the central Chinese city of Wuhan. So that’s where U.S. authorities focused their attention. In fact, the only way you could get a test was if you had recently traveled there, or had contact with someone known to be infected.
A new University of California at San Francisco genetic analysis reveals the viral lineages are diverse. While some early infections can be traced to China, others arrived from Europe.
It’s less deadly than feared
Early on, death rates varied widely by geography — but they all were scary, ranging from 2 percent in South Korea, 4.3 percent in the U.S. and 13 percent in Italy. While we assumed the risk would drop as testing expanded and infected people recovered, we didn’t have reliable numbers.
With more data emerging, the CDC has revised the estimate downward. The current U.S. death rate for those showing symptoms ranges from 0.2 percent to 1 percent, with a “best estimate” of 0.4 percent. That’s still much higher than the seasonal flu’s 0.1 percent death rate — but it’s better than we feared. Still, until there’s a vaccine, we’re all vulnerable. And the death rates for some people, such as elders and those with other illnesses, remain extraordinarily high.
It’s spreading more slowly
Initial estimates suggested each person with the virus could infect two to four people — a rate that would quickly accelerate an outbreak, if nothing were done to reduce it. A subsequent study from Los Alamos National Laboratory placed it even higher: 5.7.
Experts now calculate that the nation’s current transmission rate ranges from 0.90 to 0.95. That’s great news: A value under 1 signals fewer new cases in an area, whereas a value of over 1 means more cases.
What’s changed is our behavior, not the virus. Restrictions such as stay-at-home orders reduced infections. And if we let down our guard, it could pop back up again. Already, there are hints that reopening and relaxed behaviors are contributing to transmission rates over 1.1 in Utah and South Carolina.
Not just respiratory disease
Many early symptoms seemed to involve the lungs. Patients had pneumonia, coughed and couldn’t breathe.
Now we know that the virus can attack other parts of the body. In April, the CDC added new symptoms, such as sore throat, muscle aches and fever. Gastrointestinal problems, such as diarrhea and nausea, also have been reported. Some people complain of loss of smell and taste and neurological symptoms, like dizziness. An infection even can cause mysterious and painful lesions on the toes, weeks after acute illness.
And, disturbingly, a growing body of evidence suggests patients are suffering from strokes as a result of blood clots.
Children not completely safe
While kids make up 22.5 percent of the population, they’re only 5.7 percent of COVID-19 cases. And their illnesses are milder.
But the emergence of a rare complication shows youths aren’t completely spared. The CDC reports a serious inflammatory reaction — called “multisystem inflammatory syndrome in children” (MIS-C) — causes rashes, a persistent fever, abdominal pain and diarrhea. There have even been cases of heart failure.