FRIDAY, May 8, 2020 (HealthDay News) -- A new study illustrates just how powerful a weapon social distancing and "stay-at-home" orders can be against the new coronavirus.
Data out of Washington state show that the number of people testing positive for coronavirus in outpatient clinics fell from nearly 18% of those tested at the end of March, to just 3.8% by April 16.
The only big change during that time? On March 16, Washington state closed bars and restaurants and put strict limits on all social gatherings. On March 23, Gov. Jay Inslee also announced a "Stay Home, Stay Healthy" order, asking state residents to shelter in place.
The rapid and steep declines in coronavirus infections documented in the new study "suggest that the early and aggressive physical distancing measures enacted in Washington state have influenced the course of the COVID-19 pandemic" there, concluded a team led by Dr. Keith Jerome. He's with the Division of Vaccine and Infectious Disease at Fred Hutchinson Cancer Research Center in Seattle.
Even as many U.S. states begin to reopen beaches, parks, shops, bars and restaurants, public health experts are warning that such moves could mean a big uptick in life-threatening cases of COVID-19, overwhelming hospitals.
While reopening parts of the U.S. economy will undoubtedly start to help some Americans get their jobs back, an internal report from the Trump administration predicted that it will come at a cost: 200,000 new coronavirus cases and 3,000 deaths every day by the end of May.
But firm numbers on the effectiveness of current "shelter-in-place" orders have been hard to come by. The new research may help fill that gap.
In the study, Jerome's group tracked the results of almost 20,000 coronavirus tests (mostly nasal swabs) conducted in Washington state between March 1 and April 16. Test samples came from 127 outpatient clinics and three Seattle hospital emergency departments.
The study found that the percentage of tests coming back positive peaked on March 28-29, at 17.6% in the outpatient clinics and 14.3% in the hospital emergency departments.
But by the end of the study period, April 16, those numbers had fallen to 3.8% and 9.8%, respectively.
The researchers' conclusion: Infections with the new coronavirus among the Washington residents studied "peaked in late March and have been declining. This trajectory is aligned with [the introduction of] local physical distancing guidelines."
But Washington state, like many across America, is facing current pressure to reopen. So, "whether adherence to physical distancing will continue and how that affects [viral] acquisition trends remain to be determined," the researchers said.
The new report was published May 8 in the Journal of the American Medical Association.
The U.S. Centers for Disease Control and Prevention has more on the new coronavirus.