Oregon is expected to surpass its record of 910 pertussis cases by the end of 2024, prompting health officials to sharpen their warnings about the disease’s serious risks—especially for young babies—and their emphasis on the importance of vaccination.

As of Nov. 13, Oregon has seen a total of 827 cases of pertussis, also known as whooping cough, in 23 counties during 2024, according to Oregon Health Authority (OHA) data. At least one person, an older adult, has died.

In 2012, 910 pertussis cases were reported, the highest annual count since 1953.

“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, M.D., medical director for communicable diseases and immunizations at OHA’s Public Health Division.

Lane County has the highest number of pertussis cases this year with 249. The other counties with the highest case counts are Multnomah with 180, Clackamas with 109, Washington with 67 and Deschutes with 59. The median age of cases is 11, with the range between 5 weeks and 89 years.

Babies too young to be fully vaccinated suffer the most from pertussis, with the highest reported incidence rate and highest likelihood of hospitalization and death. This is because babies don’t start building protection against infection until they are vaccinated at 2 months old. With the exception of 2024, Oregon pertussis deaths have been limited to infants—five have occurred since 2003.

Public health experts urge pregnant people to get the Tdap vaccine – which protects a person against tetanus, diphtheria and pertussis – at 27–36 weeks’ gestation. The mothers will make antibodies and pass them to their babies across the placenta, which lowers the risk of pertussis in babies younger than 2 months by 78%–91%.

Vaccination against pertussis is routinely recommended for infants, children, adolescents and adults. Children should receive the DTaP vaccine against diphtheria, tetanus and pertussis at 2, 4, 6 and 15 to 18 months, and again at age 4 to kindergarten age. All persons 10 and older, including those 65 and older, who have not had the single-dose Tdap vaccine should get it now.

Data from January through Nov. 13 show 406 (49%) of this year’s cases had zero doses of documented pertussis vaccines, and only 361 (44%) were up to date on vaccines. Among the 75 infant cases, only 11 mothers were documented to have received the recommended dose of Tdap during pregnancy.

Before the COVID-19 pandemic—when restrictions that included masking requirements and school closures were in effect—annual case tallies routinely reached triple digits, but dropped to three in 2021. But this year’s to-date 827 cases, which represents a nearly 2,500% increase from the 32 cases reported by the same period in 2023, has surprised state and local public health officials.

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

Another reason, Guzman explained, is that early in an infection, pertussis can be confused with respiratory viral infections. “What you think may be a simple cold can turn out to be pertussis, because that's how it begins—with a mild upper respiratory infection. After a couple weeks, the whooping cough begins.”

Jennifer Gibbons, N.D., a naturopathic physician in Portland, says 80% of her family medicine practice is pediatrics, and she can cite many examples of a pertussis infection’s devastating effects on children. She recalls seeing a 5-month-old baby whose mother explained the child would have difficulty breathing and cough until she vomited, then seem fine minutes later.

“I'm talking to her, and she has this perfectly healthy-looking 5-month-old baby, who then all of a sudden starts coughing, and her face turns dark red, and she's gasping for breath while she's trying to cough up all the secretions,” Gibbons remembers. “With pertussis, they get into these spasms of coughing that they can't stop, and they're often bringing up large amounts of mucus. It's very scary.”

Cieslak, Guzman and Gibbons agree that getting children vaccinated with all doses of DTaP, and adults—particularly pregnant people—vaccinated with Tdap is the best way to protect young children, older adults, and their families and friends during the holidays, and beyond.

“I've had multiple families say, ‘If I had known how bad this was going to be, I would have vaccinated.’ I use that to tell other families,” Gibbons says. She also reminds families that “kids tolerate this vaccine very well. I find it to be a really useful, safe and effective vaccine.”

When an infant or pregnant person is in the household of someone with pertussis, all household members should receive a course of antibiotics effective against Bordetella pertussis—typically, a five-day course of azithromycin.

Source: Oregon Health Authority