Diagnostic utility of rapid antigen testing as point-of-care test for influenza and other respiratory viruses in patients with acute respiratory illness

Abstract

This study investigates the prevalence and clinical characteristics of respiratory viruses among patients with acute respiratory illness (ARI) in a low-resource setting, using a rapid antigen test as a point-of-care test (POCT). We included 343 patients presenting with ARI symptoms at an outpatient pulmonary clinic from December 2023 to April 2024. Nasopharyngeal swabs were tested for SARS-CoV-2, influenza A/B, respiratory syncytial virus, and adenovirus using POCT. The overall prevalence of respiratory viruses was 21.2 %, with influenza A being the most common (11.4 %). Shorter duration of symptoms and lower lymphocyte counts were associated with higher influenza positivity. Patients who tested positive for influenza received significantly more antiviral therapy (98.1 % vs. 39.4 %, p<0.001) and less antibiotic therapy (1.9 % vs. 28.5 %, p<0.001) compared to those who tested negative. The study highlights the utility of rapid antigen testing in enhancing antiviral and antibiotic stewardship, thereby improving clinical decision-making and patient outcomes in resource-limited settings.

Keywords: Acute respiratory illness; Rapid antigen test; influenza; low-resource setting; point-of-care test.