DENVER (KDVR) — Whooping cough cases are rising across the country and in Colorado, with a nearly 270% increase in Colorado between 2023 and 2024, according to provisional Centers for Disease Control data.

Nationally, cases of whooping cough, also known as pertussis, increased from just over 7,000 cases in 2023 to nearly 35,500 cases in 2024, according to the CDC’s provisional 2024 report. The 2023 provisional report shows Colorado had 244 cases then, while 2024 saw 655 reported cases.

According to the CDC’s website, the U.S. is returning to “pre-pandemic patterns where more than 10,000 cases are typically reported each year.” The CDC says public health authorities focus on protecting people at the highest risk for serious illness.

With this rise in whooping cough and other respiratory illnesses, it’s important to be able to see the signs and prevent exposure if possible.

What is whooping cough?

Whooping cough is a respiratory illness caused by the Bordetella pertussis bacteria that releases toxins to damage parts of the respiratory system lining, causing airways to swell.

Early symptoms can usually take between five and 10 days to appear, presenting often at first like a common cold. Runny or stuffed-up noses, low-grade fevers and mild coughs are some of the first signs, but doctors usually don’t diagnose the illness until the more severe symptoms show up, according to the CDC.

Those severe symptoms, the Colorado Department of Public Health and Environment reports, includes coughing fits that can lead to vomiting, breathlessness and the so-named “whooping” sound. These fits can last several months and are typically more frequent at night.

Infants do not usually cough when they have the illness and instead present a symptom called apnea, a pause in breathing patterns.

Serious complications such as pneumonia and convulsions can happen, and about a third of babies younger than one year old who get whooping cough have to be hospitalized. Teens and adults can also get pneumonia due to whooping cough.

How to prevent whooping cough

Whooping cough spreads from person to person when an infected person coughs or sneezes, releasing the bacteria others can breathe in. People can be contagious for weeks and unknowingly spread the illness to others if their cases are mild.

According to the CDC, outbreaks are frequent and can occur in schools, hospitals and any large geographic area.

The CDC recommends everyone should get vaccinated against the illness to best prevent it. A person exposed to the illness can also receive preventative antibiotics to minimize risk of getting sick.

Practicing good hygiene is also a productive measure to help prevent the spread of bacteria and viruses that can cause many respiratory illnesses.