Johnson County health officials are investigating 111 cases of whooping cough reported since January.
The health department issued a warning last week about the outbreak, urging residents to get the vaccine.
Johnson County and state health officials received the reports from
laboratories, doctors, schools and elsewhere. It could turn out that some of the cases are not whooping cough.
The Johnson County health department received reports of only 11 whooping cough cases all of last year.
Most of the first cases came from southern Johnson County but it has become more widespread recently. A majority of the cases are in youngsters from fifth through eighth grades but all ages have been