An Outbreak of Adenovirus Type 7 in a Residential Facility for Severely Disabled Children

Background: Adenoviruses cause a variety of clinical symptoms, involving the respiratory, gastrointestinal, urogenital, and neurologic systems. Only a few of the 55 known serotypes of adenovirus that affect humans can cause outbreaks of respiratory tract infection. Aim: To describe the characteristics and clinical manifestations of severe respiratory disease contracted by 8 physically and cognitively disabled children during a very short outbreak of adenovirus serotype 7 infection in a residential facility. Methods: The clinical, imaging, and laboratory findings of the patients who were hospitalized with severe respiratory symptoms were retrospectively reviewed. Molecular typing of the adenovirus was performed. Results: During 10 days in February 2010, 8 severely disabled children, 9 months to 5 years of age (median 22.5 months), from the same residential facility, were hospitalized due to severe acute respiratory disease with hypoxemia. Four of them (50%) needed mechanical ventilation for 2 to 8 days and one developed multisystem failure, including acute renal failure. Adenovirus serotype 7 was detected in the respiratory specimens of all 8 children. Two patients were treated with intravenous cidofovir. All 8 patients survived and were discharged after hospitalization of 6 to 15 (median: 11.5) days. The epidemiologic investigation revealed that all the 8 affected children shared a playroom and a caregiver worked with them while suffering fever, sore throat, and conjunctivitis before the onset of the outbreak. Conclusions: Adenovirus type 7 may cause short outbreaks of infection in institutions, causing children to develop life-threatening disease. Early detection of pathogens causing respiratory infections in institutions, isolation, and other preventive precautions are advocated. Moreover, vaccination of health care providers in institutions with the currently available live, oral adenovirus vaccine for types 4 and 7 should be considered.