LA CROSSE, Wis. (WKBT) -

An outbreak of whooping cough at area schools has doctors stressing the importance of getting vaccinated.

At least 15 cases of whooping cough have been confirmed in the Holmen School District and cases have also recently been confirmed in West Salem.

According to the La Crosse County Health Department, a total of 31 cases have been confirmed across the county so far.

Doctors say whooping cough can be very hard to diagnose because it looks like a common cold until the distinctive cough develops which makes it important to get immunized ahead of time.

"Unfortunately, once the cough starts and we can start to say, oh, it sounds like maybe you have whooping cough, there's nothing we can do for you. The medicine no longer works to stop the cough, it prevents you from making other people sick, but it doesn't make you any better," said Dr. C.J. Menagh from Mayo Clinic Health System.

Doctors also say if you've had contact with someone who might have whooping cough, you should make an appointment to take precautions against also catching the disease.