High incomes in Sammamish blunt COVID-19 impact

Like a major earthquake, COVID-19’s rapid spread would likely “shake us for weeks and weeks,” Dr. Jeff Duchin, health officer for Public Health — Seattle & King County, said at a March 11 press conference. The pandemic turned out to last much longer, and be far deadlier, than any recent earthquake in Washington state.

Five months on, COVID-19 continues to rock communities everywhere. Sammamish is still experiencing aftershocks today from Duchin’s metaphorical natural disaster, albeit on some measures, it is doing better than other cities in King County due the city’s status as a wealthy community.

Washington is now in the early stages of an exponential COVID-19 outbreak, and daily new cases are increasing in Sammamish, Emergency Manager Andrew Stevens said in a July 21 report to the city council. 

“By most metrics, everything is looking worse,” Stevens said, adding that the outbreak “would have zero chances of being reversed without widespread changes in behavior and policy.”

Positive COVID-19 cases in King County steeply rose from February 28 through April 1, then declined until another sudden rise started at the beginning of June, per COVID-19 data compiled by Public Health — Seattle & King County. A total of 657 people died from COVID-19 in King County as of August 5, four of whom died in Sammamish. Positive cases in the county, and in Sammamish, have once again begun to decline since late July.

Key factors such as population density and household size have set wealthier cities like Sammamish apart in terms of their capacity to impose restrictions and ultimately perform better than other parts of King County, said Dr. Ali Mokdad, a professor of health metrics sciences at the UW Institute for Health Metrics and Evaluation.

Poorer cities with less housing space may have higher population densities with more people crowded into a household, he said. More residents in those households might also have essential jobs that prevent them from staying home.

“(Essential workers) have to be out in order to get enough resources to feed themselves,” Mokdad said. “They’re struggling between paying their rents and putting food on their table or saving their lives.” 

A typical Sammamish household has 3 persons, with 85.8% of housing occupied by residents who own their units, according to 2014-2018 data from the U.S. Census Bureau. The city’s population is 64% white. 

In contrast, higher percentages of positive COVID-19 tests are concentrated in South King County, the most racially diverse part of the county where there is also a higher percentage of lower-income households, according to a Seattle Times report. 

Auburn, a South King County city, has seen an average of 11.4% positive tests for COVID-19. In contrast, Sammamish has a positive test rate of only 3.3%. 

The median household income in Auburn, where 12.6% of the population experiences poverty, is $68,947. With a median household income of $183,038 in 2018 and only 2.2% of its residents in poverty, Sammamish is ranked as the richest city in the U.S., according to 2018 census data.

“COVID-19 came on top of disparities in the United States,” Mokdad said. “I’m afraid that COVID-19 will widen these disparities because people who don’t have resources are going to be suffering the most.” 

Overall, the impact of COVID-19 in Sammamish, including the rates of positive cases, testing, hospitalizations and deaths, are all lower than the county average. 

Don Gerend, a former mayor and city council member, began recording data on positive cases and deaths at the end of March to try to better visualize how COVID-19 is spreading locally. 

Sammamish has ultimately done well in its fight against COVID-19 so far, but can still do better to help slow its transmission, Gerend said.

Cumulatively, the case count, when analyzed as a 7-day average, reflects a different story. 

Dr. Jason Williams, a research scientist at the University of Washington, created graphs with Gerend’s data that show the 7-day “trailing average” counts, or the average count of each day and the 6 prior days, in COVID-19 cases and deaths. 

The graphs compare the data as a percentage of the number of cases and deaths recorded on May 11, a chosen fixed moment in time. Using May 11 data as a baseline helps equalize the process of analyzing and comparing cities of varying sizes.

Using this methodology, Sammamish has 233.3% more positive tests as of July 29, and appears to be leading the way with more growth than any other city in King County, Williams said. King County saw a 202.4% cumulative growth in positive tests over the same period.

Gerend’s data shows Sammamish to be somewhat unstable in its progress, Williams said.

Some of the variation is due to incorrect assignment of cases to the city of a testing site instead of the city where a person lives, he said. County health officials have also experienced difficulty in precisely determining and matching causes of death to assigned cities. 

“Assigning cause of death is fraught with difficulty, and examining deaths in a given category takes careful consideration of case definitions,” Williams said in an email. “An emerging disease — a novel virus — makes this even more difficult.” 

Public behavior can also help explain how the number of cases and deaths fluctuate, Mokdad, the UW health metrics sciences professor, said. 

Mobility dropped steeply as life slowed down in many communities right after the state’s stay-at-home order went into effect, but people started to move around and interact more in anticipation of relaxed measures in early April, he said. Memorial Day marked a turning point in many communities, when people came out of their homes to celebrate together. COVID-19’s impact had softened by then and the disease was a less visible problem to the public. Subsequently, this caused another rapid rise in cases.

The threat of transmission may have faded even further out of sight for younger, less at-risk Sammamish community members, Gerend said. According to the U.S. Census Bureau, 30% of the city’s residents are under the age of 18.  

“I’m sure a lot of young people say, ‘Well, so what if I get it? It’s just like a case of flu,” Gerend said. “But if you get it then you’re also potentially transmitting it up the age group to the people that are more likely to die from it.”

He believes that even though everyone is hopeful for the arrival of a COVID-19 vaccine, people in Sammamish should do everything they can to slow the virus in the meantime.

“I think that the disappointing thing is that it just keeps persisting,” he said.