Virological Surveillance of Influenza in the eight epidemic seasons after the 2009 pandemic in Emilia-Romagna (Northern Italy)

Virological Surveillance of Influenza in the eight epidemic seasons after the 2009 pandemic in Emilia-Romagna (Northern Italy)

Authors

  • Paola Affanni Department of Medicine and Surgery, University of Parma, Italy https://orcid.org/0000-0002-7329-9248
  • Maria Eugenia Colucci Department of Medicine and Surgery, University of Parma https://orcid.org/0000-0003-4971-594X
  • Maria Teresa Bracchi Department of Medicine and Surgery, University of Parma
  • Emanuela Capobianco Department of Medicine and Surgery, University of Parma
  • Roberta Zoni Department of Medicine and Surgery, University of Parma https://orcid.org/0000-0001-8154-0719
  • Luca Caruso Department of Medicine and Surgery, University of Parma
  • Maria Rita Castrucci Department of Virology, Istituto Superiore Sanità, Rome
  • Simona Puzelli Department of Virology, Istituto Superiore Sanità, Rome
  • Angelo Cantarelli Local Health Autority, Parma
  • Licia Veronesi Department of Medicine and Surgery, University of Parma https://orcid.org/0000-0002-5399-2934

Keywords:

Influenza virus, virological surveillance, antigenic characterisation, B lineage, vaccine virus strain, mismatch

Abstract

Background and aim of the work: Influenza virological surveillance is essential for monitoring the evolution of influenza viruses (IVs) as well as for annual updating of the vaccine composition. The aim of this study is to analyse IVs circulation in Emilia-Romagna during the eight epidemic seasons after the 2009 pandemic and to evaluate their match with seasonal vaccine strains. Methods: A total of 7882 respiratory specimens from patients with influenza-like illness (ILI), were collected by regional sentinel practitioners and hospital physicians. Viral investigations were conducted by rRT-PCR assay. Genetic characterization was performed for a spatial-temporal representative number of influenza laboratory-confirmed specimens. Results: Influenza-positive samples per season ranged between 28.9% (2013-2014) and 66.8% (2012-2013). Co-circulation of IVs type A and type B was observed in all seasons, although with a different intensity. In all seasons, the highest number of positive samples was recorded in younger patients aged 5-14 years with relative frequencies ranging from 40% in the 2013-2014 season and 78% in the 2012-2013 season. Since the 2009 pandemic, A/H1N1pdm09 IVs circulating were closely related to the vaccine strain A/California/7/2009. Antigenic mismatch between vaccine strain and A/H3N2 IVs was observed in the 2011-2012 and 2014-2015 seasons. During 2015-2016, 2016-2017 and 2017-2018 seasons a complete or nearly complete mismatch between the predominant influenza B lineage of IVs type B circulating and vaccine B lineage occurred. Conclusions: This analysis confirms the importance of the virological surveillance and highlights the need of a continuous monitoring of IVs circulation, to improve the most appropriate vaccination strategies. (www.actabiomedica.it)

Author Biography

Angelo Cantarelli, Local Health Autority, Parma

Pediatrician

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Published

13-09-2019

How to Cite

1.
Affanni P, Colucci ME, Bracchi MT, Capobianco E, Zoni R, Caruso L, et al. Virological Surveillance of Influenza in the eight epidemic seasons after the 2009 pandemic in Emilia-Romagna (Northern Italy). Acta Biomed [Internet]. 2019 Sep. 13 [cited 2024 Jul. 20];90(9-S):35-44. Available from: https://mattioli1885journals.com/index.php/actabiomedica/article/view/8722