(ABC 6 News) – Parents and caregivers of high school students in the Rochester Public School district have been sent emails advising them of multiple cases of pertussis, commonly known as whooping cough, in high schools.

Pertussis is a serious bacterial illness that typically begins with mild symptoms including runny nose, sneezing, mild cough and a low-grade fever. After a week or two, symptom can worsen leading to uncontrollable coughing which can end in vomiting or a high pitched “whooping” noise.

The district has advised parents students and staff with pertussis should stay home and avoid school, work, or public activities until they have completed five days of antibiotic treatment. Those who are not treated can remain contagious for up to three weeks after they first experience symptoms.

There is currently a vaccination against pertussis, but the protection does decrease three to 5 years after the initial vaccine is given. Children typically receive their initial vaccine before they enter kindergarten.

A pertussis booster vaccine (Tdap) is available for adolescents and adults and advised for children 11 ages and adults who live with or care for infants under a year old.