Outbreak of adenovirus 35 pneumonia among adult residents and staff of a chronic care psychiatric facility

Outbreaks of acute respiratory disease caused by adenovirus are rarely documented in civilian populations, and adenovirus 35 is an uncommon serotype best recognized as a cause of serious disease in immunocompromised patients. An outbreak of adenovirus 35 pneumonia among residents and staff of a chronic care psychiatric facility was investigated. Fourteen (26%) of 53 residents and 4 (2%) of approximately 200 staff had radiographically confirmed pneumonia. Thirteen (93%) of 14 residents with pneumonia were hospitalized, 5 (36%) required mechanical ventilation, and 1 (7%) died. One staff member was hospitalized. Adenovirus infection was diagnosed in 17 (94%) persons with pneumonia by culture or serology and was confirmed as adenovirus 35 infection in 8 persons. Residents with pneumonia had resided at the facility longer than other residents. Chronic illness was not a risk factor for severe disease. Crowding and poor hygienic behaviors probably facilitated transmission among residents.