Washington state sees 'sharp increase' in whooping cough cases, mirroring rise across US

Whooping cough cases are surging in Washington state, mirroring trends seen across the United States, health officials are warning.

As of Nov. 2, nearly 1,200 cases have been reported statewide, according to the Washington State Department of Health (WSDOH), compared to just 51 cases reported at this time last year.

Over the same period, 28 people have been hospitalized, including 12 infants under the age of one, the latter of whom are at the highest risk of serious illness and death from the disease, the WSDOH said.

Additionally, of the 124 Washington state infants so far in 2024 who had whooping cough, also known as pertussis, 106 were old enough to receive a vaccine against the disease, according to a weekly update from the WSDOH.

The increase in whooping cough cases in Washington state has also been seen nationwide, with more than 22,000 cases reported in the U.S. as of the week ending Nov. 2, according to data from the Centers for Disease Control and Prevention (CDC).

That number is five times as many cases as were reported the same time last year and is the highest number of cases year-to-date since 2014, CDC data shows.

There are two types of vaccines used today to protect against whooping cough: the diphtheria, tetanus and pertussis (DTaP) vaccine for babies and children younger than age 7, and the tetanus, diphtheria, and pertussis (Tdap) vaccines for children aged 7 and older, adults and pregnant women.

Dr. Scott Roberts, an assistant professor of infectious diseases at Yale School of Medicine, said falling vaccination rates could be behind the increase in whooping cough cases. Those who receive a primary series of vaccines as children are supposed to get a booster dose every 10 years, but there have been low rates of people receiving that booster dose, Roberts said

"We are seeing declining vaccination rates, especially in people under the age of 18, and so, because of that, that is really the major reason why we're seeing the rise in whooping cough right now," Roberts told ABC News. "What's happened is they get their primary childhood vaccine series, and then they don't get that ten-year follow-up booster dose."

Whooping cough is a very contagious respiratory illness caused by a type of bacteria known as Bordetella pertussis.

These bacteria attach to the cilia – the tiny, hair-like structures found on the surface of cells – of the upper respiratory system and release toxins that damage the cilia and cause the upper airways to swell, according to the CDC.

Whooping cough is spread from person-to-person through coughing and sneezing. Infected people can be contagious for weeks without knowing they have whooping cough, the CDC says.

Early symptoms of whooping cough often resemble those of the common cold – runny nose, cough and low-grade fever – and typically last for one to two weeks. However, those symptoms can rapidly progress to cause violent coughing fits that can last up to 12 weeks.

"Somebody [asking] like, 'Well, what's the big deal about pertussis or whooping cough?' Well, the other name is called the 100-day cough," Dr. Jason Newland, chief of infectious diseases at Nationwide Children's Hospital in Columbus, Ohio, told ABC News. "And people that get this can break ribs, they can cough so much they throw up. Babies can end up in the hospital, babies can die from pertussis."

"Even if you get it, even by treating you with antibiotics, you're still going to cough for a long time," Newland added.

Dr. Mahesh Polavarapu, medical director of emergency medicine at New York-Presbyterian Westchester hospital, agrees, saying that patients can have multiple coughing attacks every day and, in some cases, every hour.

The experts say that vaccination is the best way for people to protect themselves and their loved ones against whooping cough, and stress the importance of educating the general public on the importance of vaccination and booster doses.

Newland said it's also important to remember infection prevention methods learned during the COVID-19 pandemic and apply them to whooping cough and other respiratory diseases.

"One of the first things that we learned with the pandemic, if you want to prevent infections, you can do that by keeping people away from each other," he said. "When we spread out, we wore masks, we can prevent … respiratory illness that get spread by droplets."

"If someone's super sick, stay home. Wash your hands if you're really sick and wear a mask," Newland continued. "Let's think about the most vulnerable as we go into this respiratory season with these other unfortunate illnesses that can be vaccine-preventable, like pertussis."