The MEAP-IHNV database provides access to detailed data for anyone interested in IHNV molecular epidemiology, such as fish health professionals, fish culture facility managers, and academic researchers. The flexible search capabilities enable the user to generate various output formats, including tables and maps, which should assist users in developing and testing hypotheses about how IHNV moves across landscapes and changes over time. The MEAP-IHNV database is available online at http://gis.nacse.org/ihnv/ (fig. 1). The database contains records that provide background information and genetic sequencing data for more than 1,000 individual field isolates of the fish virus Infectious hematopoietic necrosis virus (IHNV), and is updated approximately annually. It focuses on IHNV isolates collected throughout western North America from 1966 to the present. The database also includes a small number of IHNV isolates from Eastern Russia. By engaging the expertise of the broader community of colleagues interested in IHNV, our goal is to enhance the overall understanding of IHNV epidemiology, including defining sources of disease outbreaks and viral emergence events, identifying virus traffic patterns and potential reservoirs, and understanding how human management of salmonid fish culture affects disease. Ultimately, this knowledge can be used to develop new strategies to reduce the effect of IHN disease in cultured and wild fish.