5 things you need to know about whooping cough

Pertussis, more commonly known as whooping cough, is on the rise in California, with potentially deadly consequences for infants and young children.

In 2024, cases of whooping cough are about 5 times higher in the U.S. than in 2023. In California, case numbers have soared, with over 2,500 reported this year so far, compared to just 323 reported around the same time last year.

“Pertussis is a bacterium that is easily spread from one person to another through droplets from coughing and sneezing,” says Dr. Catherine Sundsmo, a family medicine doctor with Sharp Rees-Stealy Medical Group. “Although most people have been immunized as a child, the pertussis vaccine does not provide lifelong immunity.”

Here are five things you need to know about this highly communicable respiratory disease:

1. Pertussis starts with cold-like symptoms, so diagnosis can be challenging.
Early symptoms can last one to two weeks and may appear to be a common cold. Symptoms can include:

• Runny nose

• Low-grade fever

• Mild, occasional cough

• Apnea, or a pause in breathing (most common in babies under 12 months)

2. The classic “whooping” cough can take one to two weeks to appear.
Traditional signs of pertussis are fits of rapid coughing, followed by a high-pitched “whoop” sound. Children with pertussis often cough so hard they can induce vomiting and are exhausted after a coughing fit. Children may seem to feel fine in between coughing fits or may not cough much at all. However, pertussis can still be fatal.

3. Pertussis is the most dangerous for babies under 12 months.
Roughly half of babies younger than one require hospitalization. Of these children, 1 in 4 will get pneumonia and 1 in 100 will die from complications of pertussis.

4. Vaccinating pregnant women and infants is the best way to prevent the spread of pertussis.
The DTaP (diphtheria, tetanus, pertussis) vaccine — given to children younger than age 7 — is the best way to stop the spread of pertussis and minimize symptoms in those who do get it. This combination vaccine protects against diphtheria, tetanus and pertussis. Here’s who should be vaccinated:

• Pregnant women should receive the Tdap (tetanus, diphtheria, pertussis) vaccine between 27 and 36 weeks of each pregnancy — the antibodies that develop will be passed on to the baby.

• Infants should receive the DTaP vaccine starting at 2 months old, and then follow the recommended immunization schedule from the Centers for Disease Control and Prevention (CDC).

5. You may need a booster shot against pertussis, especially if you are in regular contact with babies.
“Young children and infants are at most risk of serious complications related to whooping cough, and often the infection is passed to children from other family members,” says Dr. Sundsmo. “Vaccinate all family members to decrease the chance of passing on the whooping cough to vulnerable infants.”

It’s important that parents, grandparents, siblings, caregivers and health care workers are up to date on their immunizations. Adults age 19 or older (who are not pregnant) should receive one dose of the whooping cough Tdap vaccine at least two weeks prior to contact with babies. If an adult already had the Tdap vaccine, the CDC does not recommend another vaccine.

For the news media: To talk with Dr. Catherine Sundsmo about whooping cough for an upcoming story, contact Erica Carlson, senior public relations specialist, at erica.carlson@sharp.com.