FILE - Vaccines at a pop-up clinic held at McDaniel High School in Northeast Portland, Feb. 8, 2023. Authorities of Clark County, Washington, report nearly 300 whooping cough cases so far this school year.
Kristyna Wentz-Graff / OPB
There have been 288 cases of whooping cough in Clark County, Washington, this year. That’s more cases than in the last six years combined.
So far, Clark County has more cases of whooping cough than any other county in Washington state. The largest portion of those cases is among children aged 5 and younger, according to the county’s public health department.
“I am concerned that the numbers could go up now that kids are back in school, but hopefully not,” said Dr. Alan Melnick, Clark County’s public health director and health officer.
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Despite many Clark County children returning to school Aug. 28, the number of whooping cough cases decreased slightly from August to September. But, Melnick said, one month of school data isn’t enough to know whether cases will continue to trend downward.
The respiratory illness, also known as pertussis, can be especially dangerous for infants who aren’t immunized. There has been one hospitalization in Clark County but no fatalities from the illness this year.
The number of cases in Clark County is significantly higher than in neighboring Multnomah County. According to Washington State Department of Health data, Clark County’s numbers translate to a rate of 56.6 cases per 100,000 people. The 131 cases in the more populous Multnomah County this year translate to just 16.3 cases per 100,000 people, according to the Oregon Health Authority.
Clark County immunization rates for pertussis are generally on track with the rest of Washington State. More than 92% of Clark County K-12th graders were vaccinated for pertussis in 2023-24, compared with a state average of nearly 94%.
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But Melnick said those numbers change when looking at specific schools.
“You can find schools with immunization rates in the 60s, as opposed to 90%,” he said.
In 2019, Clark County experienced a monthslong measles outbreak that resulted in 71 cases, the majority of which were in unvaccinated children. Of the current whooping cough cases, about two-thirds were in people who never received a pertussis vaccine, according to Melnick.
“We’re seeing more vaccine-preventable disease than we’ve seen before, as vaccination rates go down. That’s one of the things that keeps me up at night,” he said.