PIEDMONT, S.C. -- South Carolina's Department of Health and Environmental Control is advising parents in Anderson School District One of two cases of whooping cough at separate schools.

Letters posted on the district's website reports cases with possible exposure at Wren Middle School and Wren High School occurred on or before May 16.

Whooping cough is contagious and affects the nose, throat, windpipe and lungs. It's spread by coughing or sneezing, and people with the illness are prone to coughing fits that could lead to vomiting. It can also cause infants to stop breathing.

Pregnant women, babies and people with lung conditions or weakened immune systems are particularly susceptible.

DHEC advises parents who suspect someone in their home may be infected to contact health-care providers about starting on antibiotics.