A novel herpesvirus associated with respiratory disease in Bourke's parrots (Neopsephotus bourkii)

Abstract

A novel herpesvirus infection in nine Bourke's parrots (Neopsephotus bourkii, formerly Neophema bourkii) housed in an outdoor aviary comprised of multiple species of birds was diagnosed based on histopathology, electron microscopy and polymerase chain reaction (PCR). Clinical signs in the parrots included anorexia, ruffled feathers, depression, loss of weight and respiratory distress. The most common gross lesions were moderately congested and oedematous lungs and a mild fibrinous exudate in the air sacs and lumen of the trachea. Histological examination revealed mild to severe bronchopneumonia and airsacculitis with syncytial cells containing eosinophilic intranuclear inclusion bodies in most birds. Other less frequent changes included tracheitis, syringitis, sinusitis, rhinitis, otitis media and conjunctivitis. Attempts to culture the virus in chicken embryos and chicken embryo liver cells were unsuccessful. Examination by transmission electron microscopy of syncytial cells from the lungs of two birds revealed intranuclear virus particles typical of the family Herpesviridae. DNA from a novel herpesvirus was amplified from lung tissue by PCR using degenerate primers derived from conserved avian herpesvirus sequences. The virus belongs in the genus Iltovirus of the Alphaherpesvirinae subfamily. It is not closely related to Psittacid herpesvirus 1 that causes Pacheco's disease but does group phylogenetically with a clade of herpesviruses that cause respiratory disease in a number of avian species. The proposed name for this herpesvirus is Psittacid herpesvirus 3.

Next generation sequencing technologies: Tool to study avian virus diversity

“…CPNV associated with transmissible viral proventriculitis in broiler chicken was identified as a novel avian birnavirus, representing a distinct genetic cluster within the Birnaviridae family (Guy et al, 2011). Novel psittacid herpesvirus 3 and phasianid herpesvirus have been identified with respiratory disease in Bourke's parrots and pheasants with fatal infection, respectively (Shivaprasad and Phalen 2012;Seimon et al, 2012). An existence of a distinct avian papillomavirus group has been reported in various birds .…”

Psittacid Herpesvirus 3 Infection in the Eclectus Parrot (Eclectus roratus) in Australia

“…Herpesvirus sequences were aligned, creating a sequence of 1050 base pairs, and this sequence was then compared with the 850 base pairs of the original PsHV-3 sequence. 8 Because of the ubiquitous nature of PBFDV in Australian psittacine populations, PBFDV extraction and amplification were carried out, and both birds were positive for PBFDV, despite the lack of histologic evidence. For additional information and for the nature of the primer sets used to amplify both PsHV-3 and PBFDV, please see the online supplemental files.…”

“…Similar respiratory lesions containing herpesvirus inclusions have been reported in several other species of parrots in North America and Australia. 3,4 With the exception of a recently published article from a North American outbreak, 8 however, identification of the agent has not been reported.…”

“…It is a member of the Iltovirus genus of the Alphaherpesvirus family and was identified in an outbreak of respiratory disease in Bourke's parrots in 2011. 8 The primary target tissues for this virus were the trachea, bronchi, and air sacs, although in a number of cases, lesions were more systemic (thymus, bursa, inner ear, nasal and conjunctival epithelium, kidney, testes and ovary, thyroid, and spleen). Lesions were characterized by necrosis of the respiratory epithelium and the formation of syncytial cells containing pan-nuclear eosinophilic inclusion bodies.…”

“…Amongst psittacine birds, 3 distinct species of herpesviridae have been categorized: psittacid herpesvirus (PsHV) 1 and 2, 9 as well as a recently recognized herpesvirus isolated from Bourke's parrots (Neopsephotus bourkii) in the United States, 8 tentatively called PsHV-3 is the only genetically characterized herpesvirus that has been shown to cause respiratory disease in parrots. It is a member of the Iltovirus genus of the Alphaherpesvirus family and was identified in an outbreak of respiratory disease in Bourke's parrots in 2011.…”