EDWARDSVILLE — Another student at Liberty Middle School has been diagnosed with pertussis, which is commonly known as whooping cough.

Edwardsville District 7 sent a letter to parents warning them that a case of pertussis has been diagnosed in a student. Last month, another Liberty student was reported to have contracted pertussis, as well as a student with chicken pox.

Pertussis is a highly contagious bacterial infection spread through coughing and sneezing. It is preventable through vaccination, though maintaining the immunity requires booster shots every 10 years for adults.

It can lead to serious complications or even death in infants, the elderly and those with compromised immune systems.

Parents are warned to watch for symptoms: Pertussis appears like a common cold, with runny nose, sneezing, low fever and a mild cough. The cough worsens over a week or two and creates a spasmodic burst of rapid coughing with a characteristic whooping sound, which is violent enough to sometimes cause patients to vomit or black out.

Parents are urged to contact their child's physician if symptoms appear, or to call the Madison County Health Department at 692-8954, ext. 2. Adults also should check their own immunization history and determine whether boosters are needed.