EXPERIMENTAL SUSCEPTIBILITY OF WOOD DUCKS (AIX SPONSA) FOR WEST NILE VIRUS

Abstract

ABSTRACT:Detection of West Nile virus (WNV) has been reported in a variety of wild ducks in the US, but little is known about the pathogenesis and outcome of exposure of the disease in these species. Previous experimental studies of WNV in ducks either have challenged a small number of ducks with WNV or have tested domesticated ducks. To determine susceptibility and immune response, we challenged 7-wk-old Wood Ducks (Aix sponsa) with a 1999 American Crow (Corvus brachyrhynchos) isolate of WNV. Wood Ducks were susceptible to infection with the virus, and, although clinical signs or mortality were not observed, microscopic lesions were noted, particularly in the heart and brain. West Nile virus viremia peaked on day 2 postinfection (pi) at 10 4.54 plaque-forming units (PFU) of virus/mL serum and WNV was shed orally (between 10 2 and 10 2.9 PFU per swab) and cloacally. Specific anti-WNV antibody response was rapid, with anti-WNV IgM detected on day 3 pi followed on day 5 pi by anti-WNV IgG. Neutralizing antibodies were detected by plaque-reduction neutralization assay in one duck on day 4 pi, and in all sampled ducks on day 5. These results indicate that Wood Ducks are susceptible to WNV, but it is unlikely that significant WNV mortality events occur in Wood Ducks or that they play a significant role in transmission. However, WNV viremia was sufficient, in theory, to infect mosquitoes, and oral and cloacal shedding of the virus may increase the risk of infection to other waterbirds.

Functional analysis of duck, goose, and ostrich 2′-5′-oligoadenylate synthetase

“…Moreover, Lowenthal et al (1994) have indicated that although the initiation of development of avian immune system occurs during the embryogenesis, it is not completely developed until weeks after hatch depending on the avian species (up to 14 wks). As well, the temporary susceptibility of young duckling (Hofmeister et al, 2015;Komar et al, 2003 Shirafuji;, gosling (Austin et al, 2004;Komar et al, 2003;Swayne et al, 2001), ostriches (Allwright et al, 1995), and chicks had declined by age and these birds became resistant to WNV infection. Similar to WNV infection in ducks, Ramadori and Armbrust (2001) and Song et al (2014) clearly illustrated the age-related susceptibility to duck hepatitis virus-1 (DHV-1).…”

“…The most susceptible species belong to the Charadriiformes and Passeriformes orders and they develop severe neurological signs and high mortality rates such as the American crow with 100% mortality (Hofmeister et al, 2015;Nemeth et al, 2011). However, in other birds, they express more restrictive symptoms and death is rarely observed (Van der Meulen et al, 2005).…”

“…However, in other birds, they express more restrictive symptoms and death is rarely observed (Van der Meulen et al, 2005). In contrast, little information is known about the susceptibility of WNV infection on aquatic birds except for few reports demonstrating that WNV may cause diseases and mortality in geese (Austin et al, 2004;Glávits et al, 2005;Swayne et al, 2001) and ducks (Hofmeister et al, 2015;Shirafuji et al, 2009) as well as giant flightless birds such as ostrich (Allwright et al, 1995). Pérez-Ramírez et al (2014) indicated that the avian species could be categorized into three classes; highly competent birds (susceptible) such as Passeriformes (Corvidae and Passeridae) and…”

Newcastle disease virus-vectored West Nile fever vaccine is immunogenic in mammals and poultry

“…Several studies have additionally provided evidence of the susceptibility of domestic or captive ducks to WNV [ 3 , 53 , 54 ]. Ducks develop high-titer viremia in blood and are capable of shedding virus orally [ 55 ]. Geese are also susceptible to WNV, especially young geese, and develop a variety of neurological signs, often resulting in a significant number of deaths [ 4 , 56 , 57 ].…”

Comparative Pathology of West Nile Virus in Humans and Non-Human Animals

“…Lesions in naturally infected birds have been previously reviewed in detail by Gamino and Höfle [95]. This chart has been modified to include the most recent literature as well as pathologic findings in birds experimentally infected with WNV (Table 1) [106][107][108][109][110][111][112][113][114][115][116]. Ocular lesions are seen in raptors (red-tailed hawks, Cooper s hawks, bald eagles, golden eagles, goshawks) and owls (great horned owls, barred owls) and range from lymphoplasmacytic pectenitis and chorioretinal inflammation and scarring to generalized endophthalmitis [110,[116][117][118][119].…”