Validation of a method for preparing influenza H5N1 simulated samples

Avian influenza virus type A subtype H5N1 and potentially other novel influenza A viruses continue to pose a concern with mutation into a form easily transmitted between humans. The ability to rapidly detect and characterize influenza viruses, and distinguish seasonal and novel influenza A viruses such as H5N1, remains important to minimize morbidity and mortality in humans. As with other rare and emerging viral pathogens, clinical specimens from persons with H5N1 infections are extremely rare. Consequently, development of standardized methods and accepted criteria are necessary for both ensuring the validity of available diagnostic methods and for assessing the potential of new diagnostic tests that can detect and differentiate H5N1 and other novel influenza A viruses. Additionally, genotypic and antigenic evolution of H5N1 poses a challenge with maintaining updated reference virus strains. In this report, a method for preparing simulated samples using defined procedures and carefully selected H5N1 virus strains is described, and the reliability for using these samples in an evaluation protocol with a laboratory test for differentiating H5N1 virus from other influenza A viruses is evaluated.