Experimental infection of aquatic bird bornavirus 1 in domestic chickens

Experimental pathogenesis of aquatic bird bornavirus 1 in Pekin ducks

“…While similar symptoms have been associated with natural ABBV-1 infection in waterfowl, 7 experimental infection of Muscovy ducks and chickens with ABBV-1 failed to reproduce similar signs, except for one chicken with torticollis. 13,14 Logistic regression analysis showed that development of clinical signs in Pekin ducks was not correlated with in ammation of the CNS, in agreement with development of perivascular cuffs in numerous asymptomatic birds in the present and other studies. 13,14 It is unclear why Pekin ducks developed clinical signs, while Muscovy ducks did not.…”

“…13,14 Logistic regression analysis showed that development of clinical signs in Pekin ducks was not correlated with in ammation of the CNS, in agreement with development of perivascular cuffs in numerous asymptomatic birds in the present and other studies. 13,14 It is unclear why Pekin ducks developed clinical signs, while Muscovy ducks did not. Possible differences in the innate immune response could explain this outcome, although both species appear highly permissive to ABBV-1 infection.…”

“…13,14,17−19 The sequence of positive tissues over time indicates both centrifugal (brain to spinal cord, proventriculus, kidneys, and gonads) and centripetal (muscle to spinal cord and brain) virus spread in both the IC and IM groups, respectively, as also seen in ABBV-1 infection of chickens and Muscovy ducks. 13,14 This suggests intra-axonal virus tra cking, as proven with BoDV, 20 especially in light of the fact that viremia was not detected in our Pekin ducks.…”

“…13 Like in Muscovy ducks, inoculation of the virus via the IC and IM routes in the present study was highly e cient, leading to a 93.3% and 76.7% infection rates, respectively. However, while oral inoculation of both Muscovy ducks and chickens with ABBV-1 did not result in infection, 13,14 choanal inoculation (another mucosal route) led to infection in 4 Pekin ducks. This suggests that the upper respiratory tract is a possible, although ine cient, route of infection for ABBV-1, as also shown with PaBVs.…”

“…Recently, our research group isolated ABBV-1 from the brain of a naturally infected Canada goose 12 and used it to inoculate chickens and Muscovy ducks (Cairina moschata). 13,14 In both studies, birds became infected through the intramuscular and intracranial (but not oral) routes, although Muscovy ducks had a wider virus tissue distribution compared to chickens. 13,14 Additionally, despite minimal to no clinical signs, both species developed histologic lesions similar to those seen in naturally infected birds (i.e., mononuclear encephalitis and myelitis), con rming an association between ABBV-1 infection and in ammation of the nervous tissue.…”