Sequence analysis of respiratory syncytial virus cases reveals a novel subgroup -B strain circulating in north-central Italy after pandemic restrictions

Alessandra Pierangeli; Fabio Midulla; Antonio Piralla; Guglielmo Ferrari; Raffaella Nenna; Antonino Maria Guglielmo Pitrolo; Amelia Licari; Gian Luigi Marseglia; Dario Abruzzese; Laura Pellegrinelli; Cristina Galli; Sandro Binda; Danilo Cereda; Matteo Fracella; Giuseppe Oliveto; Roberta Campagna; Laura Petrarca; Elena Pariani; Guido Antonelli; Fausto Baldanti

doi:10.1016/j.jcv.2024.105681

Sequence analysis of respiratory syncytial virus cases reveals a novel subgroup -B strain circulating in north-central Italy after pandemic restrictions

J Clin Virol. 2024 May 10:173:105681. doi: 10.1016/j.jcv.2024.105681. Online ahead of print.

Authors

Alessandra Pierangeli¹, Fabio Midulla², Antonio Piralla³, Guglielmo Ferrari³, Raffaella Nenna², Antonino Maria Guglielmo Pitrolo³, Amelia Licari⁴, Gian Luigi Marseglia⁴, Dario Abruzzese⁵, Laura Pellegrinelli⁶, Cristina Galli⁶, Sandro Binda⁶, Danilo Cereda⁷, Matteo Fracella⁸, Giuseppe Oliveto⁸, Roberta Campagna⁸, Laura Petrarca², Elena Pariani⁶, Guido Antonelli⁹, Fausto Baldanti¹⁰

Affiliations

¹ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: alessandra.pierangeli@uniroma1.it.
² Department of Pediatrics and Infantile Neuropsychiatry, Sapienza University, V.le Regina Elena, 299, 00161, Rome, Italy.
³ Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi, 19, 27100 Pavia, Italy.
⁴ Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, via S. da Nuova, 65, 27100 Pavia, Italy; Pediatric Clinic, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi, 19, 27100 Pavia, Italy.
⁵ Pediatric Clinic, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi, 19, 27100 Pavia, Italy.
⁶ Department of Biomedical Sciences for Health, University of Milan, via C. Pascal, 36, 20133 Milan, Italy.
⁷ DG Welfare, Regione Lombardia, Piazza Città di Lombardia, 1, 20124, Milan, Italy.
⁸ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy.
⁹ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy; University Hospital Policlinico Umberto I, Sapienza University, V.le del Policlinico 155, 00161 Rome, Italy.
¹⁰ Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi, 19, 27100 Pavia, Italy; Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, via S. da Nuova, 65, 27100 Pavia, Italy.

PMID: 38733664
DOI: 10.1016/j.jcv.2024.105681

Abstract

Background: Following the pandemic restrictions, the epidemiology of respiratory syncytial virus (RSV) has changed, leading to intense hospitalization peaks.

Objectives: This study, conducted at multiple sites in Italy, aimed to describe the temporal dynamics of two post-COVID-19 RSV epidemics. Additionally, the circulating RSV-A and -B lineages were characterized and compared to those found in 2018 and 2019.

Study design: Respiratory specimens and data were collected from RSV-positive patients, both inpatients, and outpatients, of all ages at three sites in north-central Italy. To analyze these samples, roughly one-sixth were sequenced in the attachment glycoprotein G gene and subjected to phylogenetic and mutational analyses, including pre-pandemic sequences from north-central Italy.

Results: The first post-pandemic surge of RSV cases was quite intense, occurring from October 2021 to early January 2022. The subsequent RSV epidemic (from November 2022 to early March 2023) also had a high impact, characterized by a rise in elderly patient cases. Post-pandemic cases of RSV-A were caused by various strains present in Italy prior to COVID-19. In contrast, a distinct RSV-B lineage, which was concurrently spreading in other countries, was identified as the main cause of the surge in 2022-2023 but remained undetected in Italy before the pandemic.

Conclusions: This study describes the temporal dynamics of post-pandemic RSV subgroups and uncovers a lineage of RSV-B with high genetic divergence that may have increased the impact of decreased population immunity.

Keywords: Genetic diversity; Genotype; Molecular epidemiology; Pandemic restrictions; RSV-B; Respiratory syncytial virus.