Human respiratory viruses, including SARS-CoV-2, circulating in the winter season 2019-2020 in Parma, Northern Italy

Int J Infect Dis. 2021 Jan:102:79-84. doi: 10.1016/j.ijid.2020.09.1473. Epub 2020 Oct 2.

Abstract

Objectives: The aim of this study was to determine the prevalence of respiratory virus infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), during the winter period December 2019 to March 2020, via a tertiary care hospital-based survey in Parma, Northern Italy.

Methods: A total of 906 biological samples from the respiratory tract were analysed by both conventional assays (including culture) and molecular assays targeting nucleic acids of SARS-CoV-2 and other respiratory viruses.

Results: Overall, 474 samples (52.3%) were positive for at least one virus, with a total of 583 viruses detected. Single infections were detected in 380 (80.2%) samples and mixed infections were detected in 94 (19.8%). Respiratory syncytial virus (138/583, 23.7%) and rhinovirus (130/583, 22.3%) were the most commonly identified viruses, followed by SARS-CoV-2 (82/583, 14.1%). Respiratory syncytial virus predominated until February, with 129 detections; it then decreased drastically in March to only nine detections. SARS-CoV-2 was absent in the study area until February 26, 2020 and then reached 82 detections in just over a month. SARS-CoV-2 was found in mixed infections in only three cases, all observed in children younger than 1 year old.

Conclusions: This study showed a completely different trend between SARS-CoV-2 and the 'common' respiratory viruses: the common viruses mostly affected children, without any distinction according to sex, while SARS-CoV-2 mostly affected adult males.

Keywords: Culture; Diagnosis; Epidemiology; Molecular assays; Pandemic; Respiratory viruses; SARS-CoV-2.

MeSH terms

  • Adult
  • Age Factors
  • COVID-19 / epidemiology*
  • Child
  • Coinfection / epidemiology
  • Coinfection / virology
  • Female
  • Humans
  • Infant
  • Italy / epidemiology
  • Male
  • Respiratory System
  • Respiratory Tract Infections / epidemiology*
  • Respiratory Tract Infections / virology
  • SARS-CoV-2 / isolation & purification
  • Seasons
  • Tertiary Care Centers
  • Viruses / classification
  • Viruses / isolation & purification*