Decapod iridescent virus 1 (DIV1): Current advances in epidemiology, pathobiology, diagnostics, and disease management

Decapod iridescent virus 1 (DIV1) is an emerging iridovirid that infects a taxonomically diverse range of decapod crustaceans, including penaeid shrimp, freshwater prawns, crayfish, and brachyuran crabs. Infection with DIV1 is recognized by the World Organisation for Animal Health (WOAH) as a notifiable aquatic animal disease, with dedicated chapters in both the Aquatic Manual (Chapter 2.2.3) and the Aquatic Animal Health Code (Chapter 9.3). Since its initial identification in China in 2014(WOAH 2024), DIV1 has been reported in several Asian countries, with cumulative mortality rates approaching 100% in highly susceptible species under intensive aquaculture conditions. This review synthesizes current knowledge across the following eight thematic areas: nomenclature and taxonomy, host range and susceptibility, pathogenic mechanisms, clinical and histopathological features, diagnostic methodologies, epidemiology and transmission, environmental stability and inactivation, and integrated biosecurity strategies. For each area, established conclusions are distinguished from evidence gaps, and the strength of supporting evidence is critically evaluated. Priority areas for future investigations include molecular characterization of viral effector proteins, clarification of vertical transmission, functional annotation of the largely uncharacterized DIV1 proteome, and development of harmonized international surveillance standards aligned with the WOAH framework.