Whooping cough cases in McHenry County 6 times higher in 2024 than previous year

More than 80 people had pertussis in McHenry County in 2024, according to provisional data from the McHenry County Department of Health.

The county tallied more cases of pertussis in October and also in November than in all of 2023, when there were 13 cases reported for the year.

Most of the county’s 82 whooping cough cases in 2024 came during the second half of the calendar year, and double-digit cases were reported in October, November and December, according to the health department data.

While the health department noted the 2024 data is provisional, 21 cases of whooping cough were reported in October, 20 cases in November and 13 in December. Previously, health department data indicated 11 cases in November.

Health department officials said numbers may yet increase as cases are processed. The case numbers are not considered final until the Illinois Department of Public Health reviews and sends case numbers to the Centers for Disease Control and Prevention, which usually happens in the following spring or summer.

In November, the department issued a whooping cough warning and said it had seen an uptick in cases. The department didn’t specify how many cases in the release.

According to the health department, pertussis can start with mild symptoms like a runny nose, low-grade fever, and cough, progressing to intense coughing fits, sometimes accompanied by vomiting, a high-pitched “whoop” sound, exhaustion and even pauses in breathing.

Those who develop symptoms should contact their medical provider immediately, according to the release.

The county is also seeing a high prevalence of other contagious respiratory illnesses including COVID-19, flu and RSV, according to recent health department reports.

Vaccination remains the best line of defense against whooping cough, according to the health department. Frequent handwashing and covering coughs and sneezes are also important preventive measures, according to the health department.