P.E.I. health officials are still dealing with an outbreak of whooping cough.
There have been 25 confirmed cases in the province this year.
Dr. Heather Morrison, the chief public health officer, sent a letter to Summerside Intermediate School last week saying that students may have been in contact with a student with the illness.
The letter outlined the symptoms, how to prevent the spread of infection, and when they should visit their family doctor.
Parents were advised to review their family's immunization records.
Health officials say people with whooping cough are advised to stay home until five days after their treatment is completed.
This is the first outbreak on P.E.I. in a number of years, but there has been a recurrence of the illness in North America.
Whooping cough is a disease of the lining of the respiratory tract.
Symptoms usually start five to 21 days after someone has been exposed and can include cold-like symptoms, such as sneezing, runny nose, low-grade fever and a mild cough that worsens with coughing spells that often end with a "whoop" sound.
Health Minister Doug Currie spoke Wednesday in the legislature about the importance of immunization.
Basic hygiene measures, such as regular hand washing, disposing of tissues properly and containing coughs and sneezes help control the spread of whooping cough.
Infants on Prince Edward Island are routinely immunized against whooping cough at two, four, and six months and at 18 months.
Booster doses are also offered at four years of age and in Grade 9.
In addition, P.E.I. offers a free booster dose to parents of newborns and any close contacts whose immunization is not current.