| Abstrak/Abstract |
ANV has been reported in poultry flocks worldwide and predominately causes disease in chickens less than two-weeks old. Older chickens appear to be less susceptible to the clinical manifestation of the disease (Gough and McNulty 2008). The first report of ANV was in 1979 in Japan (Yamaguchi, Imada et al. 1979) however little is known about the ANV in Australia since this virus was first detected in Australian poultry in 2010 (Hewson, O'Rourke et al. 2010). ANV infection can be clinical or subclinical. In the former type of infection, clinical signs may include diarrhoea, polyurea, dehydration, growth retardation and mortality. Some of these clinical manifestations can be difficult to distinguish from those induced by nephropathogenic strains of infectious bronchitis viruses (Cumming 1999; Ignjatovic, Ashton et al. 2002). There are currently no effective treatment or control strategies for ANV infection. Complete cleanout of the shed between flocks may assist but, given that the virus is suspected to shed vertically, does not totally prevent the infection. To date no vaccine has been developed for ANV.
Diagnostic tools to detect and characterise ANV have been developed globally, however due to difficulties in adaptation of ANV to growth in cell culture, the use of molecular assays have been preferred over serological assays (Pantin-Jackwood, Todd et al. 2013). Serological assays such as ELISA have been developed, however all utilise the same Japanese strain (Shirai, Nakamura et al. 1990; Decaesstecker and Meulemans 1991; Mockett, Huggins et al. 1993) or a region-specific strain (Zhao, Zhu et al. 2012). Molecular tests, such as PCR, have been performed to confirm the presence of ANV in clinical specimens (Day, Spackman et al. 2007; Smyth, Jewhurst et al. 2010; Todd, Trudgett et al. 2010). However, the use of these molecular tests is complicated by the significant genetic diversity of ANV which reflects the large repertoire of ANV strains and complexity in serological diagnosis (Imada, Yamaguchi et al. 2000; Todd, Trudgett et al. 2010; Pantin-Jackwood, Todd et al. 2013). |
