The Public and Environmental Health Office of Colorado State University in Fort Collins, report an atypical increase in pertussis (whooping cough) cases this semester, with 14 confirmed cases to date in the fall 2025 semester.
Pertussis is a highly contagious bacterial infection that spreads through respiratory droplets when an infected person coughs or sneezes. Symptoms typically appear seven to 10 days after exposure but can develop anywhere from four to 21 days later.
Symptoms to watch for
Pertussis often starts with cold-like symptoms – cough, runny nose, low-grade fever and progresses to severe coughing fits. Impacted individuals may look and feel fine between episodes.
Warning signs include:
The illness can last six to 10 weeks, with coughing persisting for many weeks even after treatment.
What you should do
If you have a cough: Contact your physician immediately about possible pertussis exposure. If diagnosed, you’ll need to:
As the colder months begin, there is increased exposure to cold and flu viruses and other ailments. Practice safe habits such as regular handwashing, covering your mouth when coughing, and remaining at home if you are sick.
Protection and prevention
Vaccination is the best defense. Children should receive the DTaP vaccine series (Five doses by age 6), with a Tdap booster at age 11. Adults need a Tdap booster if it’s been more than 10 years since their last tetanus shot. CSU students can contact the CSU Health Network’s Immunizations Department to see if they are up to date with their TDAP vaccine.
Pertussis poses the greatest risk to infants under 12 months and individuals with chronic respiratory conditions like asthma. Vaccination protects vulnerable populations, and immunity from childhood vaccines wanes over time – making boosters essential.
According to the latest Centers for Disease Control and Prevention (CDC) data as of September 20, Colorado has reported 383 pertussis cases.