Diagnostic performance of multiplex lateral flow tests in ambulatory patients with acute respiratory illness

Abstract

ABSTRACTBackgroundWe assessed the performance of three different multiplex lateral flow assays which provide results for influenza, respiratory syncytial virus (RSV) and SARS-CoV-2.MethodsAmbulatory patients 6 months and older presenting with two or more symptoms or signs of an acute respiratory illness were enrolled in an outpatient clinic in Hong Kong. Multiplex lateral flow tests manufactured by SureScreen, Microprofit and Goldsite were performed by trained research staff using the nasal swabs from each test kit, and separate swabs were collected for RT-PCR testing.ResultsBetween 4 April and 20 October 2023, 1646 patients were enrolled and tested by at least one lateral flow test. The point estimates for all three multiplex tests had high sensitivity above 80% for influenza A and SARS-CoV-2, and the tests manufactured by Microprofit and Goldsite had sensitivity exceeding 84% to detect RSV. Test sensitivity increased with viral load. Specificity was higher than 97% for all three tests except for the SureScreen test which had specificity 86.2% (95% CI: 83.9% to 88.3%) for influenza A.ConclusionsThe multiplex lateral flow tests provided timely diagnosis of influenza, RSV and SARS-CoV-2 infection and can be used to inform clinical management and infection control such as isolation behaviours.