Whooping cough cases triple in Colorado: What you need to know
KDVR Fox 31
DENVER (KDVR) — Cases of whooping cough are on the rise across the U.S. and in Colorado, including Jefferson and El Paso counties.
Students at Cheyenne Mountain High School were given a detailed letter in October about how the school is investigating a case of the disease. Earlier in the month, Jefferson County Public Health issued a warning to residents about the highly contagious disease.
The local health departments aren't alone: In July, the Centers for Disease Control issued a warning that whooping cough was returning to pre-pandemic levels. This is concerning health officials because, in recent years, there have been as few as 2,116 reported cases of whooping cough across the U.S.
Whooping cough, also called pertussis, usually starts like a cold with a runny nose and other common symptoms, before turning into a prolonged cough, known for the "whooping" noise that sickened individuals tend to make during this portion of the illness. It is treated with antibiotics but can be prevented with a vaccine.
Whooping cough used to be very common until a vaccine was introduced in the 1940s, which is now part of routine childhood vaccinations. It is in a shot along with tetanus and diphtheria vaccines. The combo shot is recommended for adults every 10 years.
Pre-pandemic levels for whooping cough cases were in the tens of thousands — in 2019, the CDC recorded just over 18,600 cases. In 2012, the nation had over 48,200 cases of the illness.
But in 2023, the nation only had 5,611 pertussis cases — the same level of reported cases as in the 1970s. That's because while there had been a manufactured vaccine for the disease since 1948, by the mid-60s, states passed laws requiring that children be immunized before attending public school.
Why are whooping cough cases on the rise?
According to CDC data, there are 13 cases of pertussis reported in Colorado. There have been 467 total cases so far this year, with the most amount of cases at one time listed at 24. Through Oct. 19, 2023, the CDC reported that there were only 147 cases in Colorado: Over three times less than the case numbers reported in 2024.
Still, Colorado is not one of the hardest-hit states. California is reporting over 1,200 cases so far this year, and Wisconsin, Illinois and New York state (excluding New York City) are reporting similar numbers of over 1,200.
Earlier in October, the CDC reported national kindergarten vaccination rates dipped during 2023 and vaccine exemptions are at an all-time high. Data released earlier in October shows that about 92% of kindergartners nationally got the whooping cough vaccine.
Normally, the population with the most cases of whooping cough are infants and young children, but public health workers said outbreaks are hitting older kids and teens, such as the case reported at the El Paso County high school.
According to data from the National Immunization Survey, Colorado's vaccination rate for diphtheria, tetanus and pertussis vaccine at 3 months of age dropped below the national average of 87.7% in 2017, with the state reporting 86.6% of children who were three or older had received the vaccination.
The CDC said the pre-pandemic levels of whooping cough cases might be attributable to people taking fewer precautions to prevent the spread of colds and other easily spread conditions.
How to prevent spreading whooping cough
The most common way to spread whooping cough is by coughing or sneezing on people who are in close contact. The first two weeks, after the cough begins, is when health officials say people infected with pertussis are the most contagious.
The cough itself can also be dangerous: The CDC noticed that coughing fits could result in vomiting, difficulty sleeping, fracturing a rib or just being tired following the fit.
"Those who get these coughing fits say it's the worst cough of their lives," the CDC shared.
The disease also is most dangerous in delicate populations, such as babies under 1 year old. Parents can protect their infants by keeping them away from anyone with cold symptoms or who is coughing.
According to Denver Health, the best way to prevent spreading pertussis is by getting vaccinated and following up with the recommended boosters. The Jefferson County Health Department recommends Coloradans take these actions to prevent the spread of the airborne illness further:
- Wash hands frequently with soap and warm water
- Stay home when sick
- Maximize fresh air in your home
- Wear a mask to protect others you live with
Anyone who is concerned about the disease can contact their local health department or general doctor to receive care.
The Associated Press contributed to this report.