Adenovirus 7a: a community-acquired outbreak in a children’s hospital

BACKGROUND.Adenoviruses produce many illnesses in children, particularly respiratory and gastrointestinal disease. The most common adenoviral respiratory infections in children are caused by types 1, 2, 3 and 5. Adenoviruses spread rapidly in closed environments often causing epidemic disease. Serotype 7a has been responsible for outbreaks of respiratory disease in children living in close proximity with one another. This report describes a large community-acquired adenovirus 7a epidemic in hospitalized children. METHODS.Evaluation of all patients with cultures positive for adenovirus from a children’s hospital-based virology laboratory during a recognized adenovirus outbreak. All such adenovirus isolates were typed, and patients with adenovirus 7a are described by review of medical records. RESULTS.Between March 1 and July 26, 1997, 47 children admitted to the hospital were identified as infected with adenovirus. Of these 47 patients 26 (55%) were infected with adenovirus 7a. Twenty-four (92%) infections were community-acquired. The age range was 11 days to 10 years with a median of 9.5 months. Twenty-two patients (84%) had respiratory symptoms, and 21 (8%) had fever, making these the most common symptoms. The mean durations of fever and hospitalization were 5.5 and 7 days, respectively. One of 26 patients died. CONCLUSIONS.Adenovirus 7a can cause large community epidemics affecting children. The disease produced by adenovirus 7a in children is almost exclusively of the respiratory tract, and in some individuals it may be very severe and possibly fatal.