The global burden of human metapneumovirus-associated acute respiratory infections in older adults: a systematic review and meta-analysis

The human metapneumovirus (hMPV)-associated disease burden in older adults remains under-researched. We aimed to systematically estimate the global burden of hMPV-associated disease in older adults.

We searched MEDLINE, Embase, Global Health, CINAHL, Web of Science, and Global Index Medicus in February, 2023, November, 2023, and October, 2024; and CNKI, Wanfang, and CQVip, in April, 2024, and October, 2024. We included studies conducted over at least 12 consecutive months, reporting on adults aged 60 years or older, and with laboratory-confirmed hMPV infections. Critical appraisal of included studies was conducted using the Joanna Briggs Institute critical appraisal tools. To estimate the hMPV pooled proportions positive in acute respiratory infections (ARIs), random effects meta-analyses were conducted. Using Monte Carlo simulation, we estimated the hMPV-associated hospitalisations globally and separately in high-income countries, low-income and middle-income countries, and the USA in individuals aged 65 years or older in 2019, as most studies reported on this age group. The hMPV-associated ARI incidence in countries other than the USA and in outpatient or community settings in the USA was summarised narratively due to scarcity of data. The review protocol was registered on PROSPERO (CRD42023422325).