Sample collection and pathogen detection
Respiratory samples, including nasopharyngeal swabs and aspirates,
throat swabs and/or tracheal aspirates were collected from children
admitted to Queen Mary Hospital, Hong Kong for any purpose. The study
was approved by the joint Institutional Review Board of the University
of Hong Kong and the Hospital Authority Hong Kong West Cluster Research
Ethics Committee. The need for written consent was waived because
testing for respiratory pathogens is standard and routine for all
children admitted for an acute respiratory infection. Specimens were
tested by multiplex RT-PCR for influenza A, influenza B, RSV,
adenovirus, HPIV 1–4, HMPV, and enterovirus/rhinovirus as described
previously (23).