Whooping Cough Cases Spike In IL With Highest Numbers In Over A Decade

ILLINOIS — Whooping cough cases this year in Illinois are the highest the state has seen in over a decade, according to health officials.

The state had recorded more than 1,900 confirmed and probable cases of whooping cough — or pertussis — in 2024 as of early December, the highest number since 2012, according to Illinois officials citing preliminary data.

Illinois saw its largest monthly total in 20 years in October with 408 cases reported, which is more than double the number from October 2023, according to the Illinois Department of Public Health. The spike aligns with a national trend and follows a sharp drop in cases during the coronavirus pandemic.

“The post-pandemic rise in pertussis cases is a cause for concern and IDPH is monitoring this increase closely throughout the State,” Director Dr. Sameer Vohra said in a news release earlier this month. “Please speak with your healthcare provider to ensure that you and your children are up to date on your pertussis vaccinations (DTap for children under 7 or Tdap for older children and adults).”

The state has sent three health alerts flagging the rise of the illness in recent months to local health departments and providers, urging vigilance in identifying and reporting cases. Schools have also been reminded to adhere to vaccination requirements and report cases and outbreaks to local health agencies.

Pertussis is caused by the Bordetella pertussis germ, which lives in the mouth, nose and throat, and is highly contagious via coughing and sneezing, according to the state health department. An infected person is contagious from the time just before symptoms start up to three weeks after symptoms onset, although that period can be shortened with antibiotics.

Symptoms typically appear five to 10 days after exposure, begin like a common cold, and then gradually become severe with spasmodic bursts of coughing, which can last up to 100 days.

About a quarter of reported cases since 2000 have occurred in children younger than 1, according to the department, which noted infants have the highest rate of complications and death. Older children and adolescents have accounted for over half of reported cases, with adults 20 or older comprising the remainder.

Anyone who has not previously had pertussis or been vaccinated against it can get the disease. Immunization is required for school attendance. Immunity following disease or vaccination is not lifelong.