A surge in human metapneumovirus paediatric respiratory admissions in Western Australia following the reduction of SARS‐CoV‐2 non‐pharmaceutical interventions.

Aim: Western Australian laboratory data demonstrated a decrease in human metapneumovirus (hMPV) detections through 2020 associated with SARS‐CoV‐2‐related non‐pharmaceutical interventions (NPIs), followed by a subsequent surge in metropolitan region in mid‐2021. We aimed to assess the impact of the surge in hMPV on paediatric hospital admissions and the contribution of changes in testing. Methods: All respiratory‐coded admissions of children aged <16 years at a tertiary paediatric centre between 2017 and 2021 were matched with respiratory virus testing data. Patients were grouped by age at presentation and by ICD‐10 AM codes into bronchiolitis, other acute lower respiratory infection (OALRI), wheeze and upper respiratory tract infection (URTI). For analysis, 2017–2019 was utilised as a baseline period. Results: hMPV‐positive admissions in 2021 were more than 2.8 times baseline. The largest increase in incidence was observed in the 1–4 years group (incidence rate ratio (IRR) 3.8; 95% confidence interval (CI): 2.5–5.9) and in OALRI clinical phenotype (IRR 2.8; 95% CI: 1.8–4.2). The proportion of respiratory‐coded admissions tested for hMPV in 2021 doubled (32–66.2%, P < 0.001), with the greatest increase in wheeze (12–75% in 2021, P < 0.001). hMPV test percentage positivity in 2021 was higher than in the baseline period (7.6% vs. 10.1% in 2021, P = 0.004). Conclusion: The absence and subsequent surge underline the susceptibility of hMPV to NPIs. Increased hMPV‐positive admissions in 2021 can be partially attributable to testing, but test‐positivity remained high, consistent with a genuine increase. Continued comprehensive testing will help ascertain true burden of hMPV respiratory diseases. [ABSTRACT FROM AUTHOR]