A case of the highly contagious bacterial illness pertussis, also known as whooping cough, was recently reported at Nassakeag Elementary, according to a letter dated Nov. 26 on the Three Village school district website.
A school spokeswoman said Wednesday that the student has recovered and is back in school.
Two other cases of pertussis were reported in Three Village schools in 2012: once at Murphy Junior High in September and once at Gelinas Junior High in the summer during a music program.
Dr. Gregson H. Pigott of the Suffolk County Division of Public Health said in the letter that the county has seen an increase in cases of pertussis.
"The disease is a highly contagious bacterial disease that is spread through the air by cough from an infected individual," Pigott said. "Children and adults may still develop pertussis even if they are up to date with their vaccinations as immunity to pertussis wanes over the years."
According to the Suffolk County Department of Health Services, children and adults may develop pertussis even if vaccinated due to the decline in immunity to the disease. The letter, attached here as a PDF, provides information about the disease and directs parents and staff to call the county Department of Health Services at 631-853-3055 with questions about the disease or its vaccine.