Development of an MCA-Based Real Time RT-qPCR Assay for the Simultaneous Detection and Differentiation of Duck Hepatitis A Virus Types 1 and 3
- Received Date: 16 October 2019
- Accepted Date: 03 March 2020
- Published Date: 08 April 2020
Abstract: Duck virus hepatitis (DVH) is a significant concern in the duck industry as the disease causes a highly contagious infection in young ducklings that is often associated with liver necrosis, hemorrhage, and high mortality (Yugo et al. 2016). Duck hepatitis virus (DHV) was first described in 1949 on Long Island in the United States. Subsequent, outbreaks have been reported in England, Canada, Germany, Japan and elsewhere (Toth 1969). DHV is associated with at least two RNA viruses, duck hepatitis A virus (DHAV) and duck astrovirus (DAstV); however, no antigenic relationships have been identified between these two viruses (Yugo et al. 2016). DHAV is the primary causative agent of DVH. As the only member of the genus Avihepatovirus, in the Picornaviridae family, DHAV has a linear, single-stranded positive-sense RNA genome. The genomic organization of DHAV is analogous to that of other picornaviruses with one large open reading frame (ORF) that encodes a polyprotein precursor, that is preceded by a 50-untranslated-terminal-region (UTR) and followed by 30- UTR (Tseng et al. 2007). Based on systematic phylogenetic analyses and neutralization assays, DHAVs have been classified into three serotypes: the classical serotype 1 (DHAV-1) (Kim et al. 2006; Ding and Zhang 2007; Tseng et al. 2007), the second serotype that has only been reported in Taiwan Province of China (DHAV-2) (Tseng and Tsai 2007), and the third serotype that was first reported in South Korea (DHAV-3) (Kim et al. 2007). DHAV-3 also accounts for an increasing proportion of DHV pathogens in China (Liu et al. 2011; Zhang et al. 2017; Wen et al. 2018), South Korea (Cha et al. 2013; Soliman et al. 2015) and Vietnam (Doan et al. 2016).