Cases of whooping cough, also known as pertussis, are increasing across the United States in 2025. The Centers for Disease Control and Prevention (CDC) has recorded over 20,000 cases nationwide so far this year, surpassing the 19,302 cases reported during the same period last year. In 2024, there were a total of 35,435 documented cases in the U.S., a significant rise from 7,063 cases in all of 2023. States with particularly high case numbers include Washington, Oregon, California, Ohio, Michigan, Illinois, Minnesota, North Carolina and Arizona.
Health officials in Colorado have noted a noticeable increase in pertussis cases since students returned to school. The illness poses particular risks for newborns, pregnant women, health care workers and immunocompromised adults.
Lauren Bryan, infection prevention program manager at UCHealth Yampa Valley Medical Center in Steamboat Springs emphasized the importance of vaccination: “The old saying ‘An ounce of prevention is worth a pound of cure’ is so true when it comes to protecting yourself and others.” She added: “Many people minimize the impact of vaccine-preventable illnesses like pertussis, but they can be devastating to others, especially the very young, the very old and people who are immunocompromised.”
Bryan highlighted that whooping cough is highly transmissible but preventable through vaccination: “Whooping cough is incredibly transmissible but very preventable if children are vaccinated,” she said. “We saw declines in the state from 2013 to 2021, but sadly, that trend is now going the wrong way.”
Pertussis is caused by Bordetella pertussis bacteria which spread through airborne droplets. These bacteria attach to cilia in the upper respiratory tract and release toxins that damage them and cause swelling. Severe complications are common; one in three babies with pertussis requires hospitalization and one in five develops pneumonia.
The CDC notes that before COVID-19 precautions led to a drop in infections during pandemic years—with just over 2,000 cases reported nationally in 2021—whooping cough had been on an upward trend since the early 2000s due partly to vaccine misinformation.
Bryan explained how contagious pertussis can be: an estimated 80% of susceptible people will contract it after close exposure. Symptoms usually appear five to ten days after exposure but can take up to three weeks.
The illness gets its name from a characteristic “whoop” sound made when inhaling after coughing fits. The infection typically lasts about twelve weeks and progresses through three stages: early symptoms such as fever and mild cough; intense coughing fits with “whoop”; then gradual recovery as coughing subsides.
Vaccination remains key for prevention. There are two types: DTaP for children (a five-dose series starting at two months) and Tdap boosters for adolescents and adults every ten years. Pregnant women should receive Tdap between weeks 27-36 of pregnancy.
Bryan advised caregivers and health care workers also stay current on their vaccinations to protect vulnerable populations: “No one wants to infect and potentially cause harm to a baby,” she said.
To reduce spread beyond vaccination efforts Bryan recommended frequent handwashing; staying home when sick; not sending ill children to school; self-isolating within households if possible; using separate towels for sick family members; and wearing masks if public outings are necessary.
Antibiotics can help reduce symptoms if given early but may not shorten illness duration once cilia damage occurs. Exposed individuals may need preventive antibiotics even without symptoms.
Parents concerned their child might have whooping cough should consult their doctor promptly—especially if symptoms worsen or breathing issues develop—and alert providers ahead of visits or use masks at clinics.
Bryan concluded: “Again It’s important for caregivers to make sure their vaccinations are up to date as babies are particularly vulnerable… Being up to date on vaccines for people of all ages… is important for your whole health and total well-being.”
