SACRAMENTO, Calif. — Whooping cough cases are surging in California with rates returning to pre-pandemic levels, medical experts said.

As of April 26, a total of 590 Californians had contracted the highly contagious disease in 2025, according to data from the U.S. Centers for Disease Control and Prevention.

“California is one of the hot spots in the country right now,” said Dr. Peter Chin-Hong, an infectious disease specialist and professor of medicine at University of California, San Francisco.

Case rates are up by 35% in California compared to April 2024 , CDC data showed.

“Since the COVID-19 pandemic has subsided, many practices that had lowered instances of whooping cough are no longer in place, and we’re seeing the disease return to pre-pandemic levels,” Dr. Tomás J. Aragón, the director of the California Department of Public Health, said in a January news release.

Infants are particularly at risk of infection as cases become more widespread across the state, he said.

What are common symptoms of whooping cough? And how can you keep from getting sick?

Here’s what medical experts say:

What is whooping cough?

Pertussis, commonly called whooping cough, is a highly contagious bacterial disease that spreads by coughing, according to the California Department of Public Health.

The bacteria disseminates via droplets, the department said.

The most common way people contact pertussis is by being in close contact — within 3 to 6 feet — of someone coughing due to the disease.

“You stand next to somebody, they’re coughing, then you can get it,” Chin-Hong said.

Whooping cough cases tend to be cyclical, with numbers peaking in the spring and fall, according to Chin-Hong.

What are common pertussis symptoms?

Whooping cough starts out like a normal cold with a cough, Chin-Hong said, but the cough only worsens as time goes on.

According to the California Department of Public Health, people who contract pertussis experience severe coughing attacks that can last months.

“The cough is so forceful — especially among younger patients, especially infants — that (when) they cough, cough, cough, they’re expelling all the air, and they don’t even have time to inhale,” said Dr. Dean Blumberg, the chief of pediatric infectious diseases at UC Davis Health.

At the end of the coughing episode, the person takes a deep breath in, causing a “whooping” sound as air rushes back into the lungs.

That’s how whooping cough got its name, Blumberg explained.

Here are early symptoms for pertussis, according to the CDC:

•Runny or stuffed-up nose

•Low-grade fever

•Mild, occasional cough

After one to two weeks, people develop “rapid, violent and uncontrolled coughing fits,” that can last up to 10 weeks, the CDC said.

The coughing fits can cause vomiting, broken ribs, difficulty breathing, trouble sleeping at night and exhaustion, according to the federal public health agency.

“Those who get these coughing fits say it’s the worst cough of their lives,” the CDC said.

Is whooping cough on the rise in California?

Whooping cough cases more than quadrupled in California in 2024, rising from 644 cases in 2023 to 2,753 cases the following year, the state’s most recent data shows.

“We’re seeing more pertussis cases in children who’ve been admitted to the hospital than we have in the past,” Blumberg said.

Whooping cough cases dipped dramatically during the COVID-19 pandemic, which could have led to “a build-up of susceptibility in the population,” Blumberg said, causing the disease to skyrocket in the state.

Decreased vaccination rates have also brought on the spike in pertussis cases, he said.

“Overall vaccination rates have dropped over the past few years since COVID because of all the politicization of vaccines,” Blumberg said. “Even a few percent drop in vaccination rates can can lead to resurgence in these vaccine preventable diseases.”

Who is at higher risk of getting whooping cough?

“The younger you are, the higher the risk of the patient,” Dr. Blumberg said.

Infants who are too young to be vaccinated are at the most risk of contracting life-threatening cases of whooping cough, the California Department of Public Health told The Sacramento Bee in an email.

Can you die from whooping cough?

Pertussis can be fatal, medical experts said.

About one-third of babies under 1 year old who get pertussis have to be hospitalized, and about 1% die from the disease, according to the CDC.

In 2024, 62 infants who were less than 4 months old were hospitalized for pertussis in California, the state health department said.

Out of those children, one infant ended up dying from pertussis.

Whooping cough can cause serious complications such as apnea, pneumonia, convulsions and encephalopathy, the CDC said.

How is pertussis treated?

Once someone contracts pertussis, it can very difficult to treat the disease’s symptoms, Chin-Hong said.

If you think you might have whooping cough, you should notify your health care provider, Blumberg said.

Once you are tested and diagnosed with the disease, some antibiotic treatments are available.

However, these antibiotics are only relatively effective if pertussis is caught early, Blumberg said.

Chin-Hong said the best strategy to prevent infection is vaccination.

“The treatment doesn’t really get (you) better,” he said. “It’s just like supportive treatment, like you do with any cough.”

How can I avoid getting sick?

Immunization is the best preventative measure to take to avoid getting sick, Chin-Hong advised.

Other than getting the vaccine, Blumberg suggested people avoid close contact with people who are sick and coughing.

He also advised parents to keep their children home from school or daycare if they are suffering from any whooping cough-type symptoms.

What vaccines are available for pertussis?

There are two types of combination vaccines that protect against whooping cough.

DTaP, which prevents diphtheria, tetanus and pertussis, is routinely given to infants at 2, 4 and 6 months of age, then again between 15 and 18 months and finally around 4 to 6 years of age, according to the CDC.

Tdap, which protects against the same combination of diseases as DTaP, is the vaccine recommended for preteens, adults who have never been vaccinated against pertussis and women who are 27 to 36 weeks pregnant, the CDC said.

Booster shots are recommended for adults every 10 years for continued protection against the disease.

Should I get vaccinated against whooping cough?

Vaccination is recommended for all Californians, the California Department of Public Health said.

“Because protection from vaccines decreases over time, it’s important that children, adolescents and adults stay up to date on their vaccines to ensure they are protected,” the state health department said.

How effective is the vaccine?

The vaccine is about 85% effective right after it’s given, according to Chin-Hong.

“Whooping cough vaccines work but aren’t perfect,” the CDC said.

People who have received the vaccine and still contract whooping cough, tend to have milder cases, the public health agency said.

Because the vaccine has a relatively short lifespan, children and adults need to keep getting booster shots to stay protected, Chin-Hong said.

“It’s not like a one-time thing,” he said. “You need to keep on getting it, and that’s the reason why you can get all these outbreaks from time to time.”

____

©2025 The Sacramento Bee. Visit at sacbee.com. Distributed by Tribune Content Agency, LLC.