Epidemiology and Research Progress of Goose Astrovirus

Abstract

Goose astrovirus (GAstV) is a small, non-encapsulated virus, whose genome consists of a single-stranded, positive-stranded RNA molecule with a genome length of 7.1-7.3 kb. GAstV is a new member of the genus avian astrovirus in the family Astroviridae, which can be classified into two genetic subgroups (GAstV-1, GAstV-2) based on genetic homology and genetic distance, which are not yet involved in official classification. GAstV infection can lead to diarrhea, growth inhibition, and clinical signs dominated by joint urate deposition and visceral urate deposition in geese, and it is considered to be the main etiological agent causing gout in geese. There is a lack of commercialized vaccines or therapeutic drugs against GAstV, relying mainly on biosecurity measures for prevention and control. China's researchers first detected and isolated the GAstV strain in gouty geese flocks in Shandong Province in 2017. GAstV spreads quickly and radiates widely, with related cases reported in Guangdong, Fujian, and Anhui in the same year, resulting in up to 1.2 billion yuan to 1.5 billion yuan in economic losses. The incidence of GAstV can be up to 80%, and the mortality rate can be up to 50%. GAstV can lead to immunosuppression in geese, and they are susceptible to infection with other pathogens in the course of feeding, resulting in more severe clinical symptoms and increasing the difficulty of pathogen prevention and control. GAstV not only infects its natural host, geese, but also has the ability to cross the species barrier, causing diarrhea, growth inhibition, and triggering urate deposition in internal organs or joints in chickens and ducks. This suggests that GAstV may have the potential for human-animal transmission, and subsequent studies should strengthen the epidemiological monitoring of GAstV and pay close attention to the changes in its transmission characteristics. At present, scholars have made certain research progress in the pathogen detection of GAstV, and have established various technical methods that can efficiently and accurately detect GAstV. However, the research on the pathogenic mechanism of GAstV has not yet been in-depth, the research on vaccine preparation is relatively weak, and there is no uniform and effective in vitro culture method for GAstV, which has seriously hindered the pace of basic research on the pathogen. In order to better understand the impact of GAstV on goose farming industry in China, this paper reviews four aspects of GAstV, namely, pathogenesis, epidemiology, host immune response, and the association between GAstV and gout, which will provide a reference for the follow-up research and scientific control of GAstV.

Keywords

• goose astrovirus
• etiology
• epidemic trend
• pathogenicity
• gout