Avipoxvirus detected in tumor-like lesions in a white-faced whistling duck (Dendrocygna viduata)

Abstract

Avipoxvirus is the etiological agent of the avian pox, a well-known disease of captive and wild birds, and it has been associated with tumor-like lesions in some avian species. A white-faced whistling duck (Dendrocygna viduata) raised in captivity was referred to a Veterinary Teaching Hospital in Northeast due to cutaneous nodules present in both wings. A few days after the clinical examination, the animal died naturally. Once submitted to necropsy, histopathological evaluation of the lesions revealed clusters of proliferating epithelial cells expanding toward the dermis. Some of these cells had round, well-defined, intracytoplasmic eosinophilic material suggestive of poxvirus inclusion (Bollinger bodies). PCR performed on the DNA extracted from tissue samples amplified a fragment of the 4b core protein gene (fpv167), which was purified and sequenced. This fragment of Avipoxvirus DNA present in these tumor-like lesions showed high genetic homology (100.0%) with other poxviruses detected in different avian species in several countries, but none of them were related to tumor-like lesions or squamous cell carcinoma. This is the first report of Avipoxvirus detected in tumor-like lesions of a white-faced whistling duck with phylogenetic analysis of the virus.

Detection and molecular characterization of Avipoxvirus in Culex spp. (Culicidae) captured in domestic areas in Rio de Janeiro, Brazil

“…Studies conducted in the Southeastern region of Brazil, the same area of the current research, have reported the presence of APV sequences clustered in subclade A1 and isolated from both turkeys and chickens 29 , 30 . Moreover, in the Northeastern region of Brazil, Braga et al 31 isolated APVs with lineage clustering in the A1 subclade coming from a Brazilian native duck ( Dendrocygna viduata ) (Fig. 3 ).…”

“…Historically, the lineages of APVs from subclade A1 were strongly associated with Galliform hosts ( Gallus gallus and Meleagris gallopavo ) according to the results published by Gyuranecz et al 20 , Jarmin et al 32 , and Manarolla et al 21 . Nevertheless, recent records of the APVs-A1 sequence infecting a Brazilian native duck (Order Anseriformes) reported by Braga et al 31 have raised questions about this subclade’s specificity within the species of the Galliformes order. Furthermore, given the fact that the most common APV host species of subclade A1 ( Gallus and Meleagris gallopavo ) are exotic species introduced by humans as food resources in most regions of the globe, such as in Brazil, it is possible to suggest that the lineages of APVs of the A1 subclade accompany their hosts in species introduction around the globe.…”

“…Furthermore, given the fact that the most common APV host species of subclade A1 ( Gallus and Meleagris gallopavo ) are exotic species introduced by humans as food resources in most regions of the globe, such as in Brazil, it is possible to suggest that the lineages of APVs of the A1 subclade accompany their hosts in species introduction around the globe. However, given the record of an APVs-A1 infecting a native Brazilian species 31 , it is possible to suggest a community APVs-A1 transmission between different avian host species.…”

Fatal avian pox in a backyard flock of domestic ducks in Bangladesh

“…The cutaneous form of avian pox is mainly found in the unfeathered skin of birds, 1 and in ducks the cutaneous mass was seen in eyelids, beaks and legs in the humerus-radio-ulnar joint region of both wings. 27,28 Due to its distinctive clinical presentations, pox disease is remarkably simple to diagnose. However, gross and microscopic lesions, serology molecular techniques and electron microscopy can also be used to confirm the disease.…”

“…However, unlike the usual small dry scab or wart‐like lesion presentation of avian pox, a large nodular mass was seen on the leg of the examined duck gradually in other ducks from the same flock. The cutaneous form of avian pox is mainly found in the unfeathered skin of birds, 1 and in ducks the cutaneous mass was seen in eyelids, beaks and legs in the humerus‐radio‐ulnar joint region of both wings 27,28 …”