Clinical and virological impact of single and dual infections with influenza A (H1N1) and SARS-CoV-2 in adult inpatients

PLoS Negl Trop Dis. 2021 Nov 29;15(11):e0009997. doi: 10.1371/journal.pntd.0009997. eCollection 2021 Nov.

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mimics the influenza A (H1N1) virus in terms of clinical presentation, transmission mechanism, and seasonal coincidence. Comprehensive data for the clinical severity of adult patients co-infected by both H1N1 and SARS-CoV-2, and, particularly, the relationship with PCR cycle threshold (Ct) values are not yet available. All participants in this study were tested for H1N1 and SARS-CoV-2 simultaneously at admission. Demographic, clinical, treatment, and laboratory data were extracted from electronic medical records and compared among adults hospitalized for H1N1 infection, SARS-CoV-2 infection and co-infection with both viruses. Ct values for viral RNA detection were further compared within SARS-CoV-2 and co-infection groups. Score on seven-category ordinal scale of clinical status at day 7 and day 14 were assessed. Among patients with monoinfection, H1N1 infection had higher frequency of onset symptoms but lower incidence of adverse events during hospitalization than SAR-CoV-2 infection (P < 0.05). Co-infection had an increased odds of acute kidney injury, acute heart failure, secondary bacterial infections, multilobar infiltrates and admittance to ICU than monoinfection. Score on seven-category scale at day 7 and day 14 was higher in patients with coinfection than patients with SAR-CoV-2 monoinfection (P<0.05). Co-infected patients had lower initial Ct values (referring to higher viral load) (median 32) than patients with SAR-CoV-2 monoinfection (median 36). Among co-infected patients, low Ct values were significantly and positively correlated with acute kidney injury and ARDS (P = 0.03 and 0.02, respectively). Co-infection by SARS-CoV-2 and H1N1 caused more severe disease than monoinfection by either virus in adult inpatients. Early Ct value could provide clues for the later trajectory of the co-infection. Multiplex molecular diagnostics for both viruses and early assessment of SAR-CoV-2 Ct values are recommended to achieve optimal treatment for improved clinical outcome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • COVID-19 / epidemiology
  • COVID-19 / virology*
  • China / epidemiology
  • Coinfection / virology*
  • Female
  • Hospitalization
  • Humans
  • Influenza A Virus, H1N1 Subtype / genetics
  • Influenza A Virus, H1N1 Subtype / physiology*
  • Influenza, Human / epidemiology
  • Influenza, Human / virology*
  • Male
  • Middle Aged
  • Retrospective Studies
  • SARS-CoV-2 / genetics
  • SARS-CoV-2 / physiology*
  • Viral Load
  • Young Adult

Grants and funding

This study was supported by the National Natural Science Foundation of China (82173607) to XW, the Guangdong Basic and Applied Basic Research Foundation (2021A1515011684) to XW, Open Project of the Guangdong Provincial Key Laboratory of Tropical Disease Research (2020B1212060042) to XW and Guangzhou Science and Technology Project (202102080597) to XW. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.