BACKGROUND: Nasopharyngeal aspiration (NPA) is used widely in the collection of nasal specimens for respiratory virus diagnosis. The method has limitations in relation to technical expertise, patient anxiety, and apparatus dependence. Nasal washing (NW) offers an alternative approach. OBJECTIVE: To identify the merits of two different NW methods in comparison with NPA. DESIGN: Two hundred children with acute respiratory infection (ARI) were randomised to receive one of three collection devic...