Provided herein is a method for detecting the presence of a COVID-19 virus RNA or other pathogenic respiratory viruses, such as an influenza virus, or other RNA of interest in a sample. Nucleic acids are obtained from the sample and are used as a template in a combined isothermal reverse transcription, RNAse H and isothermal amplification reaction to generate single stranded RNA amplicons containing sequences complementary to fluorescent labeled detector probes. The single-stranded RNA amplicons hybridize to the detector probe and to hybridization probes with sequences complementary to a sequence determinant in the COVID-19 or other virus RNAs. The microarray is imaged to detect fluorescent signals thereby identifying the virus.