Incidence of Human Metapneumovirus Among Older Adults in 10 High-Income Countries: A Systematic Literature Review, Meta-analysis, and Modeling Study.

BACKGROUND

The epidemiologic landscape for human metapneumovirus (hMPV), a respiratory pathogen, is poorly characterized, particularly among older adults.

METHODS

Leveraging the latest estimates of lower respiratory infection (LRI) incidence from the Global Burden of Disease Study 2021 and meta-analyzed findings from a systematic literature review, we quantified the incidence of LRI with hMPV in 10 high-income locations among older adults in the most recent prepandemic year (2019): Canada, Chile, France, Germany, New Zealand, Netherlands, Italy, Spain, United Kingdom, and United States.

RESULTS

The systematic literature review identified 21 studies with data on the percentage of LRI episodes associated with hMPV in adults aged ≥60 years in the targeted locations. Combining the meta-analyzed percentage of LRI cases associated with hMPV from these studies (7.0%; 95% CI, 5.4%-9.1%) with age-, sex-, and location-specific estimates of LRI incidence from the Global Burden of Disease Study 2021, we estimated that hMPV incidence rates per 100 000 in 2019 among adults aged ≥60 ranged from 185.7 (95% uncertainty interval, 134.7-251.1) in Italy to 462.1 (333.1-628.2) in the United States.

CONCLUSIONS

Overall, our literature review, meta-analysis, and modeling study confirm a significant burden of hMPV-associated LRI in older adults. This work fills a critical evidence gap in the epidemiologic landscape of hMPV and yields actionable estimates to inform vaccine development strategies and other strategic initiatives. Future inclusion of hMPV in routine surveillance would enable more comprehensive estimates of hMPV incidence and outcomes.