Abbreviations: RSV: respiratory syncytial virus; HMPV: human metapneumovirus; PIV: parainfluenza virus.

^a Attributable fraction calculated for individuals aged <5, 5-44 and ≥45 years of age and used to adjust the observed positivity proportion among individuals aged <1 and 1-4; 5-24 and 25-44 ; and 45-64 and ≥65 years, respectively.