One case of whooping cough has been reported in the West Middlesex Area School District.

School Superintendent Alan Baldarelli confirmed Monday that an elementary school student has the respiratory illness, and the child’s family has been treated for the contagious disease.

Baldarelli wouldn’t release the child’s age or grade because of patient privacy laws or say if the student is back in school.

Baldarelli said he was notified Thursday by the student’s physician and the Pennsylvania Department of Health that the child had whooping cough, also known as pertussis.

Spokespeople for UPMC Horizon in Farrell and Greenville and the hospital of Sharon Regional Health System said Monday whooping cough has not been reported in their hospitals. The spokesperson for Grove City Medical Center, Pine Township, did not return a message.

A letter was mailed home Thursday to parents and guardians of West Middlesex students in kindergarten through sixth grade saying the children may have been exposed to whooping cough, Baldarelli said.

Teachers and other staff members were also notified to be on the lookout for students displaying symptoms of whooping cough and to stress good hygiene and hand-washing throughout the school, Baldarelli said.

Whooping cough is more common in children and Pennsylvania has about 200 reports of the illness each year, said Holli Senior, a spokesperson for the state Department of Health, adding physicians are required to report it to the department.

This particular case is not considered an outbreak, which would be defined as an unusually large number of cases reported over a short period of time, Ms. Senior said.

School officials have done everything they can by sending a letter home to parents and telling staff to be on alert, she said.

The letter lists symptoms, treatment and other information about the illness from the Department of Health, which says it is spread through the air when an infected person sneezes or coughs.

It begins with symptoms similar to the common cold, like coughing, but it becomes worse over one to two weeks. Whooping cough is caused by the bacteria Bordetella pertussis, which is found in the nose, mouth and throat of an infected person, Ms. Senior said.

Other signs of whooping cough include a long series of coughs or coughing fits followed by a whooping noise, but older children, adults and infants may not develop the whoop.

People with whooping cough don’t usually have a fever and may have a series of coughs followed by vomiting, turning blue or difficulty catching their breath, Ms. Senior said. The cough is often worse at night and cough medicines usually don’t help.

Anyone experiencing any of these symptoms — especially children who haven’t received all of the whooping cough vaccines — should contact their physician, the department said.