But state health officials say the illness isn't that widespread in Indiana.
According to the CDC, Indiana has just 118 reported cases. Last year? 367.
That means we're over halfway through the year - and three times lower than all of 2011.
That's compared to the nearly 18,000 cases have already been reported nationwide, more than double this time last year.
Illinois has a slightly higher instance rate this year than the national average. The average is 5.24 cases per every 100,000 people; Illinois is at 6.7.
In 2010, over 27,000 were diagnosed with whooping cough - the worst on record since 1959.