Three cases of pertussis, commonly known as whooping cough, have been confirmed in the Cumberland Valley School District.
District spokeswoman Tracey Panzer said two cases are at Good Hope Middle School and one is at Hampden Elementary School. She would not confirm if the infected people are students or staff.
On November 30, all Good Hope Middle School students were sent home with a letter that notified parents that someone in the school had whooping cough.
This week, some parents of middle school and Hampden Elementary students got a letter in the mail. It told parents that their child had come into "close contact" with someone who has the illness.
Dr. Karine Thevenin-Smaltz, a physician at Patient First, said the disease is highly contagious and can spread easily among students. Smaltz said whooping cough starts like the common cold, then a cough develops about a week later.
"The patient can usually present with coughing fits, persistent cough for several minutes followed by a whooping sound," Smaltz said.
Just because a child does not have symptoms, does not mean they are in the clear.
"You might not present with symptoms right away, and if you have been in contact, it might be wise to be treated," Smaltz said. "Usually, if you've been vaccinated, you have some protection against it. It's not gonna prevent you 100 percent from getting the disease, but most likely it'll prevent you from having serious complications from it."
Panzer said students must be vaccinated before they can enroll.
"To enter school, students are required to have four doses of the pertussis vaccination. The fourth dose after their fourth birthday, prior to the time they enter school, and then again for 7th grade they have to have a booster," Panzer said. "Health and safety of our students, our staff, their families and our community in general is our number one priority."
Smaltz said the main concern with whooping cough is spreading it to infants because they have not been properly vaccinated. She said about 57 percent of infants will be hospitalized if they come down with whooping cough.