Prevalence of asymptomatic SARS-CoV-2 infection in elective surgical patients in Australia: a prospective surveillance study

ANZ J Surg. 2021 Jan;91(1-2):27-32. doi: 10.1111/ans.16564. Epub 2021 Jan 9.

Abstract

Background: The study aimed to estimate the prevalence of active or previous SARS-CoV-2 infection in asymptomatic adults admitted for elective surgery in Australian hospitals. This surveillance activity was established as part of the National Pandemic Health Intelligence Plan.

Methods: Participants (n = 3037) were recruited from 11 public and private hospitals in four states (NSW, Vic, SA and WA) between 2 June and 17 July 2020, with an overall 66% participation rate. Presence of SARS-CoV-2 viral RNA was assessed by Reverse Transcriptase - Polymerase Chain Reaction (RT-PCR) analysis of nasopharyngeal swabs taken after induction of anaesthesia. Presence of anti-SARS-CoV-2 antibodies was assessed by analysis of serum collected at the same time using a novel dual-antigen ELISA assay.

Results: No patient (0/3010) returned a positive RT-PCR result. The Bayesian estimated prevalence of active infection of 0.02% (95% probability interval 0.00-0.11%), with the upper endpoint being 1 in 918. Positive serology (IgG) was observed in 15 of 2991 patients, with a strong positive in five of those individuals (Bayesian estimated seroprevalence 0.16%; 95% probability interval 0.00-0.47%).

Conclusion: These results confirm that during periods of low community prevalence of SARS-CoV-2 elective surgery patients without fever or respiratory symptoms had a very low prevalence of active SARS-CoV-2 infection.

Keywords: COVID 19; elective surgery; health policy; infection control.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Australia
  • COVID-19 / diagnosis
  • COVID-19 / epidemiology*
  • COVID-19 Nucleic Acid Testing
  • COVID-19 Serological Testing
  • Carrier State / diagnosis
  • Carrier State / epidemiology*
  • Elective Surgical Procedures*
  • Female
  • Hospitalization*
  • Humans
  • Male
  • Middle Aged
  • Prevalence
  • Prospective Studies
  • Reverse Transcriptase Polymerase Chain Reaction