Establishment of a Challenge Model for Acute Hepatopancreatic Necrosis Disease (AHPND)
Chia-Chia Chang
Abstract
Acute Hepatopancreatic Necrosis Disease (AHPND) is primarily caused by Vibrio parahaemolyticus harboring the pVA1 plasmid, which encodes the binary toxins PirA and PirB. Infected shrimp typically show characteristic pathological lesions, including pale and atrophied hepatopancreata, sloughing of hepatopancreatic tubule epithelial cells, and an empty gastrointestinal tract. AHPND can result in acute and high mortality in cultured shrimp, causing substantial economic losses to the aquaculture industry. In this study, pathogen identification and characterization were conducted to investigate the association between toxin protein expression and the virulence of different pathogenic isolates. Furthermore, a standardized in vivo AHPND challenge platform was established in shrimp. This platform provides an experimental system to address critical needs in the aquaculture industry, including early disease diagnosis, evaluation of immunostimulants, and efficacy assessment of therapeutic agents.
Long-term Surveillance of Wild Birds Reveals Extensive Reassortment and Intercontinental Gene Flow of Avian Influenza Viruses in Taiwan
Wan-Chen Li
Abstract
Situated at the eastern margin of the East Asian–Australasian Flyway, Taiwan occupies a unique geographic position for monitoring the evolutionary dynamics of avian influenza viruses circulating between Eurasia and the Americas. Through long-term surveillance of wild birds, we obtained whole-genome sequences of 59 H10 subtype viruses and conducted comprehensive phylogenetic and reassortment analyses spanning multiple migratory seasons. Genotyping resolved these isolates into 34 distinct constellations, none of which persisted beyond a single season, underscoring the transient and highly dynamic nature of reassortment events at this flyway junction. While the majority of gene segments traced to East Asian wild bird lineages, roughly one-fifth carried segments of North American origin, and further analysis identified recurrent gene pools mediating bidirectional intercontinental exchange across the circum-Pacific region—including instances of North American lineage genes becoming established within Eurasian virus populations, and vice versa. Genetic comparison with isolates from human and other mammalian hosts revealed clear phylogenetic separation, and no established molecular markers of mammalian adaptation were detected. However, temporal variation at the haemagglutinin cleavage site was observed, warranting continued monitoring for potential shifts in pathogenicity or antigenicity. Together, these findings position Taiwan as a critical sentinel site for tracking the intercontinental spread and reassortment of avian influenza viruses, and highlight the importance of sustained genomic surveillance in anticipating emerging public health risks despite the current low assessed risk to local human and poultry populations.
Society Congress
Hui-Yu Chen
Abstract
The 28th International Pig Veterinary Society Congress (IPVS 2026) was hosted by Nong Lam University in Ho Chi Minh City, Vietnam. The congress served as an international platform where researchers, veterinarians, producers, industry partners, and policymakers exchanged the latest scientific knowledge and explored recent progress in swine health and production. The congress addressed 12 scientific topics, with 'Virology and Viral Diseases' accounting for approximately one-quarter of the total presentations. Particular emphasis was placed on major swine pathogens such as porcine reproductive and respiratory syndrome (PRRS), African swine fever (ASF), porcine epidemic diarrhea (PED), and swine influenza (SI). For PRRSV control, the development of systematic and active surveillance programs is essential. Further research into viral pathogenesis and host immune responses is also needed to facilitate the development of novel vaccines. For ASF, biosecurity measures should encompass the entire swine production and supply chain, while particular attention should be paid to vaccine safety and surveillance of recombinant and emerging variants. Research on PED has primarily focused on the evolution of the S gene and the development of novel vaccines. In recent years, the cross-species transmission of avian influenza viruses to mammals, as well as the reverse zoonotic transmission of human influenza viruses to swine, has highlighted the need to address influenza prevention and control from a One Health perspective, integrating risks associated with zoonotic and interspecies transmission.