A case of Pertussis, also known as whooping cough has been confirmed at Citrus Elementary school in Chico. It happened on Thursday. According to the Centers for Disease Control and Prevention, whooping cough is highly contagious and it causes uncontrollable, violent coughing which makes it hard to breathe. A second Citrus Elementary school student has possibly been diagnosed, but it has not been confirmed. The staff at Citrus Elementary will be receiving booster shots.