PLYMOUTH, Conn. (AP) The state Public Health Department has confirmed two cases of whooping cough at a Plymouth elementary school.

The Republican American reports that Carolyn Giannini, school nurse coordinator at the Plymouth Center School, said Tuesday that students who may have been exposed have been informed in writing.

Whooping cough, also known as pertussis, is an infection of the respiratory system caused bacteria. It's characterized by severe coughing.

William Gerrish, spokesman for the Connecticut Public Health Department, said incidents of whooping cough are declining in Connecticut. In 2012, 183 cases were confirmed. That dropped to 60 the following year and 36 so far in 2014.