UW laboratory testing
INFLUENZA A, INFLUENZA
For samples that were sent to the laboratory, total nucleic acids were extracted using the Magna Pure 96 kit (Roche) and tested by TaqMan OpenArray RT‐PCR (Thermo) for multiple viral pathogens, including influenza A (H3 and H1 hemagglutinin subtypes) and influenza B. OpenArray relative threshold (CRT) values were used to determine the viral load of each sample; CRT values are inversely related to the viral load. Viral genome sequencing by hybrid capture was attempted on all influenza‐positive samples with viral loads > ~50,000 genomic copies/ml using a protocol described previously.