Whooping cough cases rising in US, more than double same time last year: CDC

Whooping cough cases are on the rise in the United States, according to data from the Centers for Disease Control and Prevention.

For the week ending April 12, at least 8,064 whooping cough cases have been recorded nationwide. This is more than double the 3,835 cases recorded at the same time last year.

Whooping cough, or pertussis, is especially dangerous for babies and young children, and several deaths have been recorded this year.

In Washington, health officials confirmed a death in a child under age 5, which is the first in the state since 2011. In Louisiana, two young infants have died from whooping within the past seven months. In Idaho, officials reported an adult resident died from whooping cough in February 2025.

"Last year, the United States had about 35,000 cases of pertussis and about 10 deaths, give or take," Chad Neilsen, head of infection control and prevention for Nemours Children's Health in Florida, told ABC News. "If we continue this pace, we'll have close to 70,000 cases of pertussis, making it one of the worst years we've seen in the U.S. in quite some time."

If that occurs, it would be the highest number of whooping cough cases recorded since 1950, CDC data shows.

Whooping cough cases have been recorded in all 50 states, according to Nielsen, who believes the increase in cases is due to a decline in vaccination rates.

A vaccine for whooping cough was introduced in the late 1940s and the number of cases each year has since dropped dramatically, decreasing more than 90% compared to the pre-vaccine era.

Before the vaccine, there were an estimated 200,000 cases annually among children and up to 9,000 children died, according to the CDC.

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

However, vaccination rates have been declining. According to a 2024 provisional CDC report, more than 7% of children between 6 months old and 6 years old who developed whooping cough were unvaccinated. This is much higher than any figure recorded since at least 2021.

Additionally, only 92.3% of kindergarteners were vaccinated against whooping cough in the 2023-24 school year, compared to about 95% before the COVID-19 pandemic began, CDC data shows.

"We think [the lack of vaccinations] is probably the primary driver of these cases right now in the U.S.," Neilsen said.

He said he believes the reasons for the drop in vaccination rates include misinformation about the safety and efficacy of vaccines as well as vaccine fatigue leftover from the pandemic.

What to know about whooping cough

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

These bacteria attach to the cilia in the upper respiratory system and release toxins. The toxins damage the cilia, tiny, hair-like structures found on the surface of cells, 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.

Early symptoms often resemble a common cold -- runny nose, cough and low-grade fever -- and typically last for one to two weeks. Symptoms, however, can progress to rapid, violent cough coughing fits that can last up to 12 weeks.

Infants under age one, pregnant women and immunocompromised people are at highest risk, but anybody can develop the condition.

Babies who contract whooping cough may have a cold-like illness, struggle to breathe or have apnea, the CDC said.

Whooping cough can be treated with antibiotics and receiving treatment early can reduce the severity of the infection. Most whooping cough symptoms can be managed at home, according to the CDC.

To drive vaccination rates up, Neilsen said it's important to explain the seriousness of whooping cough to the public.

"Pertussis, like measles, are not just run-of-the-mill diseases," he said. "These can cause harm ... to some of our youngest people. These are diseases that children get [and] they become extremely ill."

He said the other important thing is to address the concerns of vaccine-hesitant parents, educating them on the safety and efficacy of the vaccine.

Nielsen added that people may have forgotten how contagious or life-threatening whooping cough is because of how effective the vaccine has been at reducing cases.

"We've got new doctors who have never seen measles, they've never seen pertussis," Neilsen said. "It was only something they saw on textbooks. The vaccines were so successful.

ABC News Youri Benadjaoud contributed to this report.