Thirteen students at Seattle’s Roosevelt High School have been treated for whooping-cough since mid-October, Seattle Public Schools said Thursday.
In a letter to families, the district encouraged students to cough into their shirtsleeves instead of into open air and to wash their hands vigorously.
Officials also said some students were fully vaccinated against the disease but still got sick.
Jeff Duchin, chief of communicable disease and immunization for Seattle and King County Public Health, said students who have not received a dose of the vaccine against whooping-cough as a teenager should get a booster. The vaccine can wane over time, he said.
But he also said that the number of cases at Roosevelt is not unusual and King County as a whole has fewer cases of whooping-cough now than it did last year at this time.
Whooping cough, clinically known as Pertussis, is a highly contagious bacterial infection passed along by airborne particles in crowded places, like schools. It can cause frequent deep, dry coughs and can last up to several months.
The district has not seen any new cases of whooping-cough in more than a week, district spokeswoman Stacy Howard wrote in an email. “It seems to be under control,” she wrote.