IDM report says Washington in an “explosive situation” for COVID-19 transmission

The Institute for Disease Modeling’s latest situation report describes Washington State as being in an “explosive situation” when it comes to COVID-19 transmission. In all areas of the state except Yakima, indicators of viral spread are higher than the previous week.



Similar to the previous IDM situation report, researchers estimate the effective reproductive number (Re) for western Washington is between 1.34 and 1.73 (1.54 best estimate). For eastern Washington, Re is higher than last week, though statistically similar at a best estimate of 1.41.

“With recent effective reproductive numbers definitively above 1, we have complete confidence that the COVID-19 epidemic was growing in both eastern and western Washington through June. Without any changes the burden on all our communities will accelerate in the coming weeks,” reads the report.


Image: Institute for Disease Modeling


The report notes that Spokane, specifically, “has been experiencing accelerating exponential growth in COVID-19 burden that has yet to show significant signs of slowing.”

The latest data also shows that hospitalizations are beginning to increase in western Washington after failing since April and remaining steady in June. The increase is being driven primarily by hospitalizations among 20-39 year olds. In eastern Washington, daily hospitalizations are continuing to trend upward for all age groups.


Image: Institute for Disease Modeling


“Washington State is in the early stages of an exponential statewide outbreak that has zero chance of being reversed without changes to our collective behavior and policies to support that change,” reads the report.

IDM says that compliance with mask wearing, social distancing, and additional restricted gathering guidelines are needed for transmission control.