



SEATTLE -- Public health officials and researchers say social distancing appears to be helping slow the spread of COVID-19 in the Seattle area, where many of the first U.S. deaths occurred.

Dr. Jeff Duchin, the public health officer for Seattle and King County, said Monday a new analysis by the Bellevue-based Institute of Disease Modeling provides a powerful indication that the region needs to double-down on the policies it’s already adopted.

“What we’re doing now appears to be working,” Duchin said. “We need to continue this for weeks.”

In two papers released Monday, the Institute for Disease Modeling acknowledged that much remains unknown about rates of infection, but based on available data and a variety of assumptions, its computer models suggest that a measure of transmission — an estimate of how many people are infected by each person who is already infected — has fallen.

In late February, each person with COVID was infecting about 2.7 other people; by March 18, that number had dropped to 1.4, the researchers found.


They cautioned that the numbers were rough estimates. Duchin said he felt confident saying the rate of transmission is lower than it was, but he wouldn’t put much stock in the precise figure.

To see a drop in the number of new cases, the measure of transmission would have to be below 1.

There are now more than 4,850 confirmed COVID-19 cases in Washington state and at least 195 deaths, as of Sunday, March 29.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in several weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia and death.