Pertussis is on the rise in Eastern Oregon’s most populated county.

Umatilla County first reported an outbreak of the bacterial disease earlier this month. Public health officials said the respiratory illness has now spread in multiple schools.

As of Wednesday morning, Umatilla County Public Health reported 21 cases. Public health director Joe Fiumara said his department suspects there are likely more undocumented infections.

The county is facing this outbreak at a time when pertussis is resurgent across Oregon. Last year the state recorded the highest number of cases since 1950.

Patients with pertussis, also known as whooping cough, often initially show cold-like symptoms, but with a cough that becomes more intense over time.

“That’s one of the problems with stemming the spread of this,” Fiumara said, “your initial symptoms are a mild fever, runny nose and a cough. Very non-specific. There’s a lot of other diseases circulating this time of year — flu, RSV, the common cold — that look very similar.”

Pendleton High School reported a case of pertussis last month. Fiumara said it’s already spread to other schools in the county. He’s especially worried that this trend will lead to the disease hitting a vulnerable population.

“Ultimately, we want to protect the infants and the small kids,” he said. “Those are really the highest risk individuals for this disease, and we want to make sure those folks have the information to take proper precautions.”

The most effective tool against pertussis is vaccination, Fiumara said, both for reducing the spread of the disease and making the symptoms milder.

Oregon requires children to get the pertussis vaccine to attend public schools, unless their families seek an exemption. Fiumara said he previously hoped Umatilla County’s high compliance rate would spare it from an outbreak.

According to the Oregon Health Authority, 96% of the county’s K-12 students are vaccinated against pertussis. Some 84% of Umatilla children aged 5 or younger also have the vaccine.

Despite those strong numbers, Fiumara said vaccination rates have dropped in recent years. He said anti-vaccine sentiment grew during the COVID-19 pandemic.

“We know there was some trust loss, some frustration, some confusion and a lot of misinformation. All of that kind of combines with some folks making some different decisions.”

Last year in Oregon, pertussis was reported in 23 counties, breaking a record for the highest number of cases recorded since 1950. At least one person, an older adult, died. In Washington state, pertussis cases exploded from 51 cases in November 2023, to nearly 1,200 a year later. Cases of pertussis in Idaho rose 20 times higher in that period.

As the superintendent of InterMountain Education Service District, Mark Mulvihill has helped coordinate the pertussis response of schools across Umatilla County.

Mulvihill said COVID-19 has helped sharpen schools’ readiness for illness outbreaks, improving how they report them and keeping affected students out of schools.

Unlike during the pandemic, Mulvihill doesn’t anticipate any school shutdowns, mask requirements or supplying staff with personal protective equipment. But he said preventing illness in schools is a safety issue and vaccinations are an important part of that.

“Vaccines aren’t just for an individual.” he said. “They’re for a group.”

Fiumara said Umatilla County Public Health has pivoted from trying to identify and contact individual cases, to focusing on public outreach and working with health care providers.

Umatilla County is a “health care desert,” he said, meaning there aren’t enough providers for all the people who need care, so he wants to avoid current providers from being overwhelmed with pertussis cases.

News Source : https://www.opb.org/article/2025/03/14/umatilla-county-pertussis-outbreak/