Parrot bornavirus in naturally infected Brazilian captive parrots: Challenges in viral spread control

Abstract

Psittaciform orthobornaviruses are currently considered to be a major threat to the psittacine bird population worldwide. Parrot bornavirus (PaBV) was identified recently in Brazil and, since then, few studies have been conducted to understand the epidemiology of PaBV in captive psittacine birds. In the present study, natural infections by PaBV in South American parrots were investigated in two breeding facilities: commercial (A) and conservationist (B). Thirty-eight psittacine of 21 different species were presented for postmortem examination. Tissue samples were collected and investigated for the presence of PaBV-RNA using RT-PCR. In addition, clinical information about these birds was used when available. PaBV infection was detected in 73.7% of all birds investigated, indicating a wide dissemination of this virus in both facilities. From birds investigated in aviary A, 66.7% showed clinical signs, 100% had typical lesions of proventricular dilatation disease (PDD), 100% had mild to severe proventricular dilatation and 88.9% were PaBV-positive. In birds from aviary B, 27.6% showed clinical signs, 65.5% had typical lesions of PDD, 62% had mild to severe proventricular dilatation and 69% were PaBV-positive. Neurological disease was observed more frequently than gastrointestinal disease. Sequencing analysis of the matrix gene fragment revealed the occurrence of genotype 4 (PaBV-4) in both places. About 15.8% of birds in this study are threatened species. We discussed the difficulties and challenges for controlling viral spread in these aviaries and implications for South American psittacine conservation. These results emphasize the urgent need to develop a national regulatory and health standard for breeding psittacine birds in the country.

Evolutionary Analysis of a Parrot Bornavirus 2 Detected in a Sulphur-Crested Cockatoo (Cacatua galerita) Suggests a South American Ancestor

“…This study incorporated a comprehensive set of PaBV sequences and available epidemiological information to present a global view of this virus’s diversity. In Brazil, a few molecular studies with phylogenetic analyses on avian bornaviruses have mainly indicated the presence of the PaBV-4 genotype in captive and free-living birds [ 11 , 12 , 14 ]. PaBV-8 was identified and proposed as a new genotype but has only been detected in Brazil [ 15 ].…”

“…In Brazil, known for its highly diverse avifauna and being the richest in psittacines, PaBVs have been detected in captive and free-ranging psittacines and Passeriformes [ 11 , 12 , 13 ]. These infections have mainly corresponded to the PaBV-4 genotype [ 11 , 12 , 14 ], with the PaBV-8 genotype unique to this country [ 15 ]. This study describes a severe case of PDD in a sulphur-crested cockatoo (Cacatua galerita) and includes comparative molecular and evolutionary analysis with other PaBV strains worldwide.…”

Surveillance of Parrot Bornavirus in Taiwan Captive Psittaciformes

“…Parrot bornavirus is the causative agent of proventricular dilatation disease (PDD), and infection leads to a chronic neurological and digestive disorder in psittacine birds. PaBV presence has been reported in Brazil [4][5][6]; Germany [7][8][9][10][11]; France and Spain [9]; Portugal [12]; the Netherlands [8]; Sweden [13]; Austria, Switzerland, Hungary, and Australia [14]; the United States [15][16][17][18]; Canada [19,20]; South Africa [21]; the Czech Republic and Slovakia [22]; Qatar [23]; Israel [18]; Malaysia [24]; Thailand [25]; China [26]; South Korea [27]; and Japan [28,29]. The detection rates of PaBV vary significantly among these countries.…”