Evidence of pertussis clusters in three aged-care facilities in the former Macquarie Area Health Service, NSW.

During a limited outbreak of pertussis in an area health service in NSW, three clusters occurred in aged-care facilities--the first reported outbreaks of pertussis in Australian nursing homes. The attack rates across the three clusters were 16.7% for staff and 15.7% for residents. Our investigation revealed that older adults are not immune to pertussis. We suggest methods for controlling a pertussis outbreak in an aged-care facility.