Multicenter Cross-sectional Study on the Epidemiology of Human Metapneumovirus in Italy, 2022–2024, With a Focus on Adults Over 50 Years of Age - Report - MDSpire

Multicenter Cross-sectional Study on the Epidemiology of Human Metapneumovirus in Italy, 2022–2024, With a Focus on Adults Over 50 Years of Age

  • By

  • Alessandro Mancon

  • Laura Pellegrinelli

  • Greta Romano

  • Elisa Vian

  • Valeria Biscaro

  • Giulia Piccirilli

  • Tiziana Lazzarotto

  • Sara Uceda Renteria

  • Annapaola Callegaro

  • Elisabetta Pagani

  • Elisa Masi

  • Guglielmo Ferrari

  • Cristina Galli

  • Francesca Centrone

  • Maria Chironna

  • Claudia Tiberio

  • Erasmo Falco

  • Valeria Micheli

  • Federica Novazzi

  • Nicasio Mancini

  • Tiziano Giacomo Allice

  • Francesco Cerutti

  • Elena Pomari

  • Concetta Castilletti

  • Eleonora Lalle

  • Fabrizio Maggi

  • Matteo Fracella

  • Paolo Ravanini

  • Giulia Faolotto

  • Roberta Schiavo

  • Giuliana Lo Cascio

  • Carla Acciarri

  • Stefano Menzo

  • Fausto Baldanti

  • Guido Antonelli

  • Alessandra Pierangeli

  • Elena Pariani

  • Antonio Piralla

  • on behalf

  • AMCLI-GLIViRe Working Group

  • Laura Sandri

  • Sandro Binda

  • Federica Giardina

  • Antonino M G Pitrolo

  • Patrizia Bono

  • Gabriele Arcari

  • Alessandra Lombardi

  • Antonia Palumbo

  • Salvatore Curiale

  • Eva Caterina Borgatti

  • Federica Tontarelli

  • Fabrizio Carletti

  • Ombretta Turriziani

  • Annamaria Colacicco

  • July 16, 2025

  • 0 min

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Clinical Report: Epidemiology of Human Metapneumovirus in Italian Adults ≥50 Years

Overview

This multicenter cross-sectional study analyzed 96,460 respiratory viral tests in Italy from 2022 to 2024, revealing an overall human metapneumovirus (hMPV) positivity rate of 3.4%, with 2.6% positivity in adults aged 50 and older. Seasonal peaks occurred in February 2023 and April 2024, and phylogenetic analysis showed predominance of specific hMPV clades, highlighting hMPV as a relevant respiratory pathogen in older adults.

Background

Acute respiratory infections remain a major public health challenge, with human metapneumovirus (hMPV) causing a spectrum of illness from mild to severe, especially in older adults and those with comorbidities. hMPV is classified into two antigenic types, A and B, with multiple subtypes and lineages that vary seasonally. The COVID-19 pandemic disrupted hMPV circulation, leading to an 'immune debt' that may influence current epidemiology. Understanding hMPV's postpandemic epidemiology is essential for guiding surveillance and vaccine development.

Data Highlights

ParameterValue
Total respiratory viral tests analyzed96,460
Overall hMPV positivity rate3.4%
hMPV positivity in adults ≥50 years2.6%
Proportion of adults ≥50 years aged >80 yearsApproximately 33%
Seasonal peaks of hMPV casesFebruary 2023 and April 2024
Geographic variationSome variation, with higher outpatient detection in northwest Italy

Key Findings

  • hMPV was detected in 3.4% of respiratory viral tests overall and 2.6% among adults aged 50 and older.
  • One-third of hMPV-positive adults aged ≥50 were older than 80 years, indicating vulnerability in the very elderly.
  • Seasonal peaks occurred in February 2023 and April 2024, with overlapping timing in the general and elderly populations but some geographic variation.
  • In northwest Italy, hMPV was more frequently detected in outpatients than hospitalized patients, suggesting community circulation.
  • Phylogenetic analysis revealed an even distribution of hMPV types A and B, predominated by clades A2c with a 111-nucleotide duplication and B2b.
  • Previously circulating clades A2c with a 180-nucleotide duplication and B2a may have become extinct.

Clinical Implications

hMPV is a significant respiratory pathogen in older adults, particularly those over 80 years, who may be at increased risk for severe outcomes. Awareness of seasonal peaks and circulating clades can inform diagnostic vigilance and guide targeted prevention strategies, including vaccine development for this vulnerable population.

Conclusion

This study provides comprehensive epidemiological and molecular insights into hMPV circulation among older adults in Italy post-COVID-19 pandemic, underscoring the importance of continued surveillance and tailored preventive measures to mitigate hMPV-related morbidity in aging populations.

References

  1. Authors/GLIViRe Network/2024 -- Epidemiological Insights into Human Metapneumovirus Among Adults Aged 50 and Older in Italy

Original Source(s)

Multicenter Cross-sectional Study on the Epidemiology of Human Metapneumovirus in Italy, 2022–2024, With a Focus on Adults Over 50 Years of Age

  • by Alessandro Mancon, Laura Pellegrinelli, Greta Romano, Elisa Vian, Valeria Biscaro, Giulia Piccirilli, Tiziana Lazzarotto, Sara Uceda Renteria, Annapaola Callegaro, Elisabetta Pagani, Elisa Masi, Guglielmo Ferrari, Cristina Galli, Francesca Centrone, Maria Chironna, Claudia Tiberio, Erasmo Falco, Valeria Micheli, Federica Novazzi, Nicasio Mancini, Tiziano Giacomo Allice, Francesco Cerutti, Elena Pomari, Concetta Castilletti, Eleonora Lalle, Fabrizio Maggi, Matteo Fracella, Paolo Ravanini, Giulia Faolotto, Roberta Schiavo, Giuliana Lo Cascio, Carla Acciarri, Stefano Menzo, Fausto Baldanti, Guido Antonelli, Alessandra Pierangeli, Elena Pariani, Antonio Piralla, on behalf, AMCLI-GLIViRe Working Group, Laura Sandri, Sandro Binda, Federica Giardina, Antonino M G Pitrolo, Patrizia Bono, Gabriele Arcari, Alessandra Lombardi, Antonia Palumbo, Salvatore Curiale, Eva Caterina Borgatti, Federica Tontarelli, Fabrizio Carletti, Ombretta Turriziani, Annamaria Colacicco

  • July 16, 2025

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