Relationship between upper respiratory tract influenza test result and clinical outcomes among critically ill influenza patients

Abstract

Among critically ill patients with lower respiratory tract (LRT)- confirmed influenza, we retrospectively observed worse 28-day clinical outcomes in upper respiratory tract (URT)-negative versus URT-positive subjects. This finding may reflect disease progression and highlights the need for influenza testing of both URT and LRT specimens to improve diagnostic yield and possibly inform prognosis.