COVID-19 transmission flattening, not enough to reverse skyrocketing trends from November

OLYMPIA—Washington State remains in a highly precarious situation, even as COVID-19 transmission begins to flatten. A report released on December 24, 2020, showed that there has been a substantial decrease in transmission, however, it is not enough to reverse the skyrocketed rates that followed the Thanksgiving holiday.

The report indicates, based on the timing of this trend, the case count plateau may be due, in part, to the current restrictions on gatherings and certain businesses. The report finds include:

• COVID-19 transmission is plateauing but hasn’t decreased enough. The best estimate of the reproductive number (how many new people each COVID-19 patient will infect) on Dec. 5 was 1.03 in western Washington and 1.11 in eastern Washington. The goal is maintaining a reproductive number well below one—meaning COVID-19 transmission is declining—for a substantial amount of time.

• Daily hospital admissions of patients with confirmed COVID-19 have been relatively flat statewide since early December. Admissions increased gradually through Oct. 31, accelerated through Nov. 23, briefly dropped over the week of Thanksgiving, then rebounded until early December. We expect high hospital occupancy to last beyond drops in admission since COVID-19 patients generally stay in the hospital longer than one day.

• Some counties are plateauing. Some mid-sized counties (Benton and Cowlitz) and some small counties (Douglas, Okanogan and Walla Walla) have seen flattening to pre-Thanksgiving levels.

• The estimated overall percentage of Washington state residents with active COVID-19 infection was still higher than the peak in late March. The best model-based estimate as of Dec. 5 was 0.41%. Prevalence estimates started to flatten in mid-November, but remain several times higher than at the start of October.

“Because of the high levels of disease activity Washington state has seen this fall, we are looking for more than just a flat trend. We need to see a significant decrease in cases and hospitalizations, and the only way to get there is to intensify our current efforts to control the spread of the virus,” said Dr. Umair A. Shah, secretary of health at DOH. “It is encouraging to see that those efforts have helped the state avoid a post-Thanksgiving spike. If we want to maintain this progress going into the new year, we must take every precaution possible including limiting in-person celebrations to our immediate households.”

DOH partners with the Institute for Disease Modeling, Fred Hutchinson Cancer Research Center, University of Washington, and the Microsoft AI for Health program to develop these reports every other week. More COVID-19 data can be found online at the DOH data dashboard and in the state’s risk assessment dashboard.