MISSOULA, Mont. -

The Ravalli County Health Department reports four more people are sick with pertussis. The outbreak has now climbed to 38, and two of the new cases are children.

The Missoula Health Department had clients coming in all day Friday. A Sentinel High School student tested positive for pertussis this week. It's the first whooping cough case in Missoula County since January. On normal days the Missoula Health Department answers about two calls on pertussis.

But, right now said infectious disease nurse Cindy Hotchkiss,"we're answering 30 to 40 calls in the infectious disease office and I can't tell you how many people are coming in the clinic. They're very busy."

"I heard about it on the news that there was a kid at Sentinel who had whooping cough," said Julie Steckler, "and I work in several schools, so I just want to take a preventive measure." Steckler and her husband both got booster shots.

Many people who came into get pertussis vaccination updates work in Missoula schools. The director of Missoula County Public Schools human resources came to get his shot. Steve McHugh said, "there are so many people walking in and out of our office, I just think we should get it done."