Molecular testing for respiratory viruses

Respiratory tract infections (RTIs) are a spectrum of diseases associated with infection of both the upper and the lower respiratory tract. These diseases include the common cold, otitis media, influenza-like illness, croup, bronchiolitis, and pneumonia. Viruses are the most common cause of RTI and include influenza viruses, respiratory syncytial virus, human metapneumovirus, parainfluenza viruses, adenovirus, rhinoviruses, enteroviruses, and human coronavirus. These viruses have been responsible for two recent pandemics, the 2009 H1N1 influenza pandemic and the coronavirus disease 2019 (COVID-19) pandemic. It is often difficult to clinically differentiate viral and bacterial etiologies for some respiratory diseases. Nucleic acid amplification assays provide a rapid and extremely sensitive means to detect respiratory viruses. Multiplex and point-of-care molecular assays for respiratory viruses are widely utilized. Understanding the biology and pathogenesis of the associated viruses is key to understanding diagnostic testing limitations.