Respiratory diseases and infectious risk: a new study highlights the impact of human metapneumovirus on elderly Italians
Human metapneumovirus (hMPV) is a respiratory agent that is one of the most common causes of airway diseases, with a wide range of severity levels, affecting all age groups but especially young children and the elderly.
A large multicentre study carried out by Sapienza University of Rome, University of Milan and the University of Pavia collected and analysed data obtained between 2022 and 2024 from seventeen centres distributed throughout the country and affiliated with the working group on respiratory infections (GLIViRe) of the scientific society AMCLI, highlighting the spread of the virus and its impact on older individuals.
The research, funded by the National Recovery and Resilience Plan as part of initiatives on emerging infections, was published in the prestigious journal ‘The Journal of Infectious Diseases’ in an issue entirely dedicated to hMPV.
“The study, says Guido Antonelli of Sapienza’s Department of Molecular Medicine, co-author of the study and head of the “Microbiology and Virology” unit at the Policlinico Umberto I General Hospital in Rome, analysed almost 100,000 respiratory samples from patients of all ages, both outpatients and hospitalised patients, finding a hMPV positivity rate of 3.4%. In the over-50 age group, the positivity rate was 2.6%, with one-third of cases found in individuals over 80 years of age."
The results revealed two seasonal peaks of the virus, in February 2023 and April 2024. Although there were some geographical variations, the incidence was similar among the general population and the elderly. In some North-West areas, hMPV was found more frequently in outpatients than in hospitalised patients.
Genetic analysis of viral strains revealed a balanced distribution between the two main subtypes of the virus (hMPV-A and hMPV-B), with a predominance of emerging variants and the disappearance of some previously circulating strains.
“The results clearly indicate that hMPV is a significant respiratory pathogen, especially in older adults,” continues Alessandra Pierangeli, professor of virology and co-author of the study. “This highlights the importance of developing targeted preventive strategies, including possible vaccines, to protect the most vulnerable segments of the population.”
This research is the first study of its kind in Italy, representing a fundamental step towards improving our understanding of hMPV epidemiology. It provides a useful reference source for assessing the cost-benefit ratio in the event of a future vaccination campaign, and supports the authorities in developing targeted public health interventions.
References
A. Mancon, L. Pellegrinelli, G. Romano, E. Vian, V. Biscaro, G. Piccirilli, T. Lazzarotto, S. Uceda Renteria, A. Callegaro, E. Pagani, E. Masi, G. Ferrari, C. Galli, F. Centrone, M. Chironna, C. Tiberio, E. Falco, V. Micheli, F. Novazzi, N. Mancini, T.G. Allice, F. Cerutti, E. Pomari, C. Castilletti, E. Lalle, F. Maggi, M. Fracella, P. Ravanini, G. Faolotto, R. Schiavo, G. Lo Cascio, C. Acciarri, S. Menzo, F. Baldanti, G. Antonelli, A. Pierangeli, E. Pariani, A. Piralla, AMCLI-GLIViRe Working Group, on behalf, Multicenter Cross-sectional Study on the Epidemiology of Human Metapneumovirus in Italy, 2022–2024, With a Focus on Adults Over 50 Years of Age, The Journal of Infectious Diseases, Volume 232, Issue Supplement_1, 15 July 2025, Pages S109–S120, https://doi.org/10.1093/infdis/jiaf111 https://doi.org/10.1093/infdis/jiaf111
Further Information
Guido Antonelli
Department of Molecular Medicine
Alessandra Pierangeli
Department of Molecular Medicine