The Boone County Department of Health has seen eight cases of whooping cough in the last three weeks.

The Columbia Public School's health director says Ridgeway Elementary School has confirmed three cases and that a second school has a possible case. Officials won't identify the second school until the case is confirmed.

This week Columbia Public Schools officials are sending letters to parents to help them recognize symptoms. At first, those symptoms can seem like those of the common cold. Common symptoms include:

- Fits of coughing usually at night.
- A high pitched "whooping" sound.
- Stomach sickness.
- A decreased effectiveness of cough medicine.

"It is highly contagious, and it's particularly dangerous for babies and elderly or those who are compromised," Columbia Public Schools Health Director Susan Robinson said. "They could end up getting hospitalized if they're not treated."

Officials say increases in whooping cough cases happen every three to five years. They say parents should be aware, but not alarmed.