97 percent of Washingtonians need to wear masks, wash hands if we’re to stop COVID, experts say
COVID-19 transmission rates are growing across Washington and positive cases of the disease are surging, according to a report released recently by the state Department of Health, and that has officials worried.
“Continuing along this trajectory will lead to catastrophic outcomes for health and economic well-being in Washington,” the July 3 situation report warned.
The report was compiled by the health department, the Institute for Disease Modeling and Microsoft AI for Health.
Niket Thakkar, research scientist at the Institute for Disease Modeling, worked on the report. Thakkar said one of the main takeaways is that, in order to stem the spread of the disease, close to 97 percent of people need to adhere to public health measures like mask wearing, hand washing and social distancing.
“A majority is not enough,” he told The News Tribune.
“We’ve seen a lot of societal change, and that change has born positive effects that we’ve seen in the data, but that doesn’t mean it’s enough to stop these outcomes that we know our health care systems in our society can’t handle.“
The Department of Health’s July 3 situation report said there is an urgent need to increase mask use, maintain physical distancing and perform more testing.
Health department officials are monitoring case numbers, testing and contact tracing against ideal benchmarks in The Washington Phase and Risk Assessment dashboard. The data shows a steady rise in the rate per 100,000 people of new cases in recent weeks.
On June 30, the rate was 77.9 new cases per 100,000. As of July 2, the 14-day rate was 83, reaching the highest rate recorded by the health department during the coronavirus pandemic.
The report outlines several worrisome figures.
Transmission
Rates of transmission have been divided into Western and Eastern regions, with the Cascades as the dividing line.
From March 26 to May 30, the rate of transmission was 1 or lower for Western Washington, meaning someone with COVID-19 would spread the virus to one other person on average.
Since May 30, virus transmission has increased to an estimated 1.7. That is lower than the beginning of March when the state estimated one person would infect an estimated 3.8 people, but Thakkar said more recent data shows a continuing increase in transmission.
The Eastern Washington rate of transmission remained around 1 (R) — or “rate of reproduction” of the virus — or higher since the beginning of the pandemic, according to the state dashboard.
Eastern Washington counties recently have seen an increase to 1.3, which is the highest recorded rate east of the Cascades and not seen since May 28. Spokane, Benton and Franklin counties have seen an increasing transmission rate and case count. Cases also are rising in neighboring areas, the report said.
Benton, Franklin and Yakima were approved on July 3 to move into an expanded Phase 1 of Gov. Jay Inslee’s Safe Start plan.
Thakkar said health experts were not sure what transmission would look like when the state opened back up, seeing as so much of transmission is based on human behavior.
There are now more younger people becoming infected with the coronavirus, a King County study concluded on July 2.
“This is becoming a much younger epidemic than it was in February or in March,” Thakkar said.
The type of infection also can change transmission rates. An unknown number of cases is caused by asymptomatic infections, where the person with COVID-19 shows no symptoms.
Asymptomatic people are seen as “super spreaders” because they show no symptoms while transmitting the virus to others. It is still unclear how frequently cases are asymptomatic, but Thakkar said it could be anywhere from 30 to 50 percent.
“I think it’s undeniable at this point that a large fraction of infections are asymptomatic,” he said.
There also is a difference in causes of transmission by region, Thakkar said. People in Yakima County have been less likely to stay home than those in King County, a May study showed. Thakkar said that is likely due to a difference in socioeconomic status.
Those in lower income brackets have spent less time at home than those in higher income brackets over the last six months.
“In King County, the dominant industry is professional scientific and technical services,” he said. “Whereas the dominant industry in Yakima is agricultural and forestry services, and a lot of that can’t be done at home.”
But in recent weeks, more people in Western Washington are leaving their homes more frequently, and there has been a quick rise in transmission. The Institute for Disease Modelling is watching cell phone data, and a lot of more people are going out in the Puget Sound, Thakkar said.
Increased cases
On July 6, the state reported the highest daily increase since the pandemic began, with 1,086 confirmed COVID-19 cases.
King, Snohomish and Pierce counties are seeing daily counts revert back to the height of the pandemic in April.
King County saw 206 new COVID-19 cases on July 1, a number not seen since mid-April. Pierce County reported close to it’s April high of 69 cases with a 66-case daily increase on July 3. Snohomish County had 52 new cases on July 2. The last time the county saw a similar daily increase was in mid-April.
In the Puget Sound region, there has been an increase in positive test rates and case counts across the region, the July 3 situation report said. Much of the increase in cases has come from counties in Phase 1 or 2, where businesses have been allowed to reopen with some restrictions.
Pierce County is in Phase 2. The percentage of Pierce County residents testing positive for COVID-19 was reported at 6.2 percent from June 26 to July 2 in the state dashboard, compared to the 3.6 percent a month earlier.
Snohomish has reached 5.7 percent positive, and King is at 4.1 percent.
While testing has increased across the state, the report said the daily number of confirmed cases is growing faster than the number of tests.
“This gives confidence that the epidemic is growing, and the cases are not an artifact of increased testing,” the report said.
Wearing masks is critical
Inslee ordered a statewide mask mandate that took effect June 26.
Between June 24 and June 26, the health department surveyed the number of masks at 89 grocery stores in the Puget Sound area.
According to the random survey, in more than 85 percent of the selected grocery stores, less than 90 percent of shoppers wore masks.
Mask compliance needs to increase, Thakkar said.
The report points to Hong Kong, where there has been success in reopening. An estimated 97 percent of the population wears masks there.
The virus transmission isn’t equal for everyone. Some will pass the coronavirus to five people, while others might not infect anyone.
“To really catch those rare events, you need mask usage to be exceedingly high,” Thakkar said.
Yakima County has seen a drop off in cases in recent days, believed to be largely due to mask policies, Thakkar said.
“In Yakima County, things were going really fast for a long time, but more recently, they seem to have turned around,” he said. “And that timing is correlated with a lot of the masking campaigns.”
This story was originally published July 10, 2020 at 5:00 AM with the headline "97 percent of Washingtonians need to wear masks, wash hands if we’re to stop COVID, experts say."
