Pertussis is caused by Bordetella pertussis and before the vaccine era typically causes epidemics every three to five years. In 2012, there were 1,736 confirmed and probable cases reported to IDPH or 57 cases for every 100,000 persons in Iowa, which accounts for a 344 percent increase in activity from the previous three-year average of 391 and had been at the highest level since 2003.
Seventy percent of 2012 cases occurred in children ages 0 to 14 years. Three percent of pertussis cases were hospitalized, and no deaths were reported. The highest rates occurred in Fayette, Howard, Cerro Gordo, and Worth.
The most common symptoms are paroxysms (fits of coughing, 64%), followed by posttussive vomiting (29%), whooping (14%), and apnea (15%). Rare, but serious secondary conditions reported included pneumonia, encephalopathy, and seizures.
For more detailed information and statistics on all notifiable diseases, please see our current annual report.