Pacific Northwest Sees Surge in Whooping Cough Cases

An undated image produced by the U.S. Centers for Disease Control and Prevention shows a whooping cough, or pertussis, bacteria cluster. Courtesy of the CDC

An increase in pertussis, also known as whooping cough, has been reported in the Pacific Northwest states of Oregon, Washington, and Idaho.

Oregon has a total of 827 cases of pertussis in 23 counties during 2024, according to a Nov. 14 statement from the Oregon Health Authority (OHA). This is an approximately 2,500 percent jump from the 32 cases reported last year.

In Washington, there were 1,303 cases, far higher than the 54 reported in 2023, while Idaho has had 25 cases. Last year, there were five.

Whooping cough is found only among humans and is spread by the Bordetella pertussis bacteria. These microbes attach to the tiny, hair-like extensions inside the upper respiratory system, releasing toxins and causing airways to swell. It’s spread via air through coughing or sneezing.

In Oregon, Lane County had the highest number of cases this year at 249, with two more counties reporting more than 100 each. The median age of affected individuals was 11 years.

“It’s concerning,” said Lisandra Guzman, Lane County’s deputy public health officer. “Pertussis is very contagious, and that’s one of the reasons it’s so hard to control.”

The record for the highest annual pertussis number of cases in Oregon was in 2012, when 910 incidents were reported. The OEA said that case numbers this year are on “track to pass” the 2012 figure. So far this year, one person—an older adult—has died from the condition.

The agency noted that babies too young to be fully vaccinated against pertussis have the highest likelihood of hospitalization and death. Other than this year, all five deaths since 2003 have been among infants.

“I’m worried, given the time of year, because people are attending indoor holiday gatherings, and those gatherings often include newborns who are too young to be vaccinated,” said Paul Cieslak, medical director for communicable diseases and immunizations at OHA’s Public Health Division.

Nationwide Situation

In Washington, whooping cough has been identified in 31 counties, with Chelan, Clark, and Whitman reporting the highest incidences. As of Nov. 2, there were 28 hospitalizations this year, including 12 infants under the age of 1.

The department noted that infants, especially those below 1 year, are at the highest risk of severe illness from whooping cough.

“To protect babies from whooping cough, people of all ages should get up to date on pertussis vaccination, and anyone with symptoms should see a health care provider to see if testing and antibiotic treatment are needed,” said Tao Sheng Kwan-Gett, pediatrician and chief science officer at the department.

According to the U.S. Centers for Disease Control and Prevention, five times more pertussis cases have been reported this year than during the same period in 2023. The case numbers in 2024 are also higher than what was seen in 2019, before the COVID-19 pandemic.

“Reports of pertussis cases were lower than usual over the past few years, during and following the COVID-19 pandemic,” the agency said.

“However, the United States is beginning to return to pre-pandemic patterns where more than 10,000 cases are typically reported each year. It’s likely mitigation measures used during the pandemic (e.g., masking, remote learning) lowered transmission of pertussis.”

Thomas Murray, a Yale Medicine pediatric infectious diseases specialist, agrees.

“Levels of pertussis dropped dramatically when we were all masking, and now this huge increase is getting us back to pre-pandemic levels, and probably a little above that,” he said, according to a Sept. 16 post by Yale Medicine.

“It’s a contagious respiratory illness that can spread fairly quickly through the population.”

The CDC noted that people can spread the pathogen right after symptoms begin and for at least two weeks after coughing starts.

Some people with mild symptoms may not know they have pertussis and can unknowingly spread the pathogen.

“Many babies who get whooping cough are infected by older siblings, parents, or caregivers who don’t know they have it,” the agency said.