Pertussis: A Cluster of Linked Cases in a Wichita, Kansas Primary School

Recognizing pertussis outbreaks in schools is challenging. From September 26th to October 29th 2007, an outbreak of Bordetella pertussis in a Kansas primary school with high vaccination rates was investigated. Disease reports were obtained through telephone interviews with parents of all case subjects by trained reviewers. Thirteen of cases of confirmed B. pertussis infection were identified. Ages ranged from 7 – 14 years, with children aged 7-9 years (2nd and 3rd grade) comprising 85% of the cases. From available immunization records, childhood vaccine coverage in this sample was estimated at 100% (all 5 DTaP doses). Symptoms of case patients included cough (100%), post-tussive vomiting (30%), whoops (44%), and apnea (30%). No case patients were hospitalized or developed pneumonia.

The start of the outbreak could be linked to a specific second grade classroom. Transmission of the bacterium to a subsequent 3rd grade classroom was likely due to repeated contact during music program rehearsals involving 2nd and 3rd graders. The cases in the 5th and 8th grade were each linked to a sibling in the 2nd grade. Because of its severity in young unvaccinated infants, preventing pertussis in this population through early recognition, treatment, and chemoprophylaxis is of greatest importance. The Wichita experience with pertussis confirms the value of communication between local health departments and the schools, particularly school nurses, clear disease-reporting guidelines, community wide surveillance, and aggressive outreach.