School-associated pertussis outbreak--Yavapai County, Arizona, September 2002-February 2003.

On September 21, 2002, a pertussis case (confirmed by isolation of Bordetella pertussis) was reported to the Yavapai County Health Department (YCHD). The patient was a child aged 13 years in the 8th grade at a middle school in Yavapai County; the child had attended school during the illness. A case consistent with the clinical definition of pertussis had been reported in another student in the same classroom 2 weeks earlier. On September 22, a second culture-confirmed case was reported from the same classroom. Subsequent investigation identified five additional persons (two students in the same classroom, two 8th-grade teachers, and one parent of an ill student) with prolonged cough illnesses. In comparison, during the previous 10 years, an average of four pertussis cases were reported annually from this county. On September 26, YCHD, in conjunction with the Arizona Department of Health Services (ADHS) and school officials, notified the community of the pertussis outbreak in the middle school and initiated control measures. This report summarizes the epidemiology of the outbreak and the control measures used to contain it. Health-care providers should consider pertussis in persons of any age with acute cough illnesses and consider obtaining nasopharyngeal (NP) specimens for B. pertussis culture.