Respiratory virus surveillance and outbreak investigation.

Sensitive, rapid detection of respiratory viruses is needed for surveillance and for investigation of epidemiologically linked cases. The utility of rapid antigen-based methods for detection of common respiratory viruses and to confirm the cause of outbreaks is well established. However, nucleic acid amplification tests (NATs) offer some benefits above antigen or culture-based procedures, with the main advantages being sensitivity and range of pathogens detectable. It is important to understand how changes in our testing methodology alter respiratory virus detection and information for epidemiological studies. For viruses such as influenza A, influenza B and respiratory syncytial virus, NATs offer enhanced sensitivity above antigen assays but still identify the seasonal peaks important for predicting disease and managing time-sensitive prophylaxis. For other viruses, such as rhinoviruses, coronaviruses, human bocavirus and parainfluenza virus type 4, culture and antigen-based procedures are not available and/or lack sensitivity. Thus such targets would be missed if NATs were not included in testing for surveillance and outbreak investigation. As more respiratory viruses are identified there is a need to expand surveillance and further evaluate new technologies and automation beyond currently-available diagnostics to address detection of a broad range of potential pathogens.