Near real-time severe acute respiratory illness surveillance characterising influenza and COVID-19 epidemiology in hospitalised adults, 2021-22

Abstract

Objectives: We report the findings of a novel enhanced syndromic surveillance that characterised influenza- and SARS-CoV-2-associated severe acute respiratory illness (SARI) in the 2021/2022 winter season.

Methods: Prospective cohort study of adults admitted to the Queen Elizabeth University Hospital, Glasgow, with a severe acute respiratory illness. Patient demographics, clinical history, admission details, and outcomes were recorded. Data were available to Public Health Scotland (PHS) and clinicians weekly.

Results: Between November 2021 and May 2022, 1063 hospitalised SARI episodes in 1037 adult patients were identified. Median age was 72.0 years, and 44.5% were male. Most (82.6%) SARI cases had ≥1 co-morbidity; chronic lung disease (50.0%) and malignancy (22.5%) were the most frequently reported. Overall, 229 (22%) and 33 (3%) SARI episodes were SARS-CoV-2 and influenza A PCR positive, respectively. 74.7%, 6.5% and 43.0% SARI episodes received antibiotics, antivirals, and steroids, respectively (54.5%, 11.0% and 51.3% among COVID-19 patients). 1.1% required mechanical ventilation and 7.8% died. Male sex, multimorbidity, frailty, respiratory rate >30, low GCS and chest X-ray consolidation were predictive of in-hospital mortality.

Conclusion: Near real-time hospitalised SARI syndromic surveillance characterised the evolving clinical epidemiology of SARS-CoV-2 and influenza, high antimicrobial use, and predictors of inpatient mortality among hospitalised SARI patients.

Keywords: COVID-19; Influenza; SARS-CoV-2; Severe acute respiratory illness; Syndromic surveillance.