Molecular characterization and pathogenicity of novel Malaysian chicken astrovirus isolates

Pathogenesis of Chicken Astrovirus Related Illnesses

“…Although other viruses have been implicated in cases of RSS, underperformance, and growth checks, recent studies have identified CAstV as the sole etiologic pathogen responsible for the condition in chickens and turkeys (10,12,20,39). Similarly, DNA and RNA extracted from birds exhibiting underperformance, growth checks, and amplified using various enteric virus-specific primers were consistently positive for CAstV but negative for other enteric viruses (9,17,40). Next-generation sequencing and metagenomic approach, as an alternative, have been used to detect the presence of CAstV in the clinical samples (6,41,42).…”

“…Shortly after the discovery of astrovirus in 1975, small round virus particles with astrovirus morphology were recorded in domestic animals, particularly calves and lambs with gastroenteritis (32,33) and ducks with viral hepatitis in the early 1980s leading to acute mortality (34), which conceivably served as the earliest indication of extra-intestinal tropism of astrovirus (35). Over the years, chickens, especially the broiler types, are found to be susceptible to varying conditions caused by astrovirus (4,9). Within a few years of discovery, two distinct genogroups of CAstV (Group-A and Group-B) have been described.…”

“…Similarly, with the exception of PL/059/2014 strain of Poland, a member of the Aiii subgroup, all the other strains responsible for white chick syndrome (WCS) originating from Canada and Brazil are clustered in Biv. Recently, in a study using SPF chickens, a Malaysian CAstV strain (UPM1019/2018) caused nephropathy and gouty lesions but were less severe compared to the UK and Indian strains (9).…”

“…The prevalence and incidence of the virus have been reported in the UK, the US, Germany, China, Finland, Poland, Nigeria, South Africa, the Netherlands, and the Middle East (1-7). In the UK and Malaysia, a seroprevalence investigation reveals seropositivity of CAstV in four generations of broilers and broiler breeder flocks, respectively, (8,9). Since the initial detection of CAstV in the flocks of commercial broiler chickens in 2004 (10), new strains of CAstV have been identified and characterized in chickens worldwide (5,9,(11)(12)(13)(14)(15)(16)(17).…”

“…Despite the progress made in the detection and characterization of novel CAstVs (9,14,17,21,22), there is still a dearth of knowledge about its pathogenesis. Studies on both human and turkey astroviruses have demonstrated an increase in the permeability of intestinal epithelial cells, leading to the disruption of tight junctions between the cells (23,24).…”