PARROT BORNAVIRUSES IN PSITTACINES KEPT IN CAPTIVITY IN THE STATE OF SANTA CATARINA, BRAZIL.

Parrot bornaviruses are responsible for proventricular dilatation disease (PDD) in psittacines. This study aimed to determine the occurrence and factors associated with Parrot bornaviruses infection in psittacines kept in captivity in a state in the southern region of Brazil. A cross-sectional study was carried out with 192 birds from two facilities (A and B) in 2019, using choanal, esophageal, and cloacal swabs and feathers, totaling 768 samples subjected to reverse-transcription polymerase chain reaction (RT-PCR), for the matrix (M) protein gene with a final product of 350 base pairs (bp). Genetic sequencing of three positive samples was performed by the Sanger method. In the study, the overall virus occurrence was 35.9% (69/192), with 40.4% (42/104) in Facility A and 30.7% (27/88) in Facility B. Sequencing analysis of the samples revealed the presence of Parrot bornavirus 2 (PaBV-2) in both facilities. Swab samples from the choanal (40/69), esophageal (30/69), cloacal (35/69), and feather (15/69) tested positive, facilitating the molecular diagnosis of Parrot bornaviruses. The results indicated that there is no single ideal sample type for antemortem molecular diagnosis of this virus. Simultaneously testing all four samples at the same time point yielded more diagnoses than testing any single sample among the four. Most of the 29 sampled psittacine species were native, and 46.9% of the birds (90/192) consisted of endangered species. Among the psittacines that tested positive, 88.4% (61/69) were clinically healthy, and 8.7% (6/69) exhibited clinical or behavioral signs, including behavioral changes, alterations in feathering, and changes in body score at the time of collection. This study showcases the application of minimally invasive sampling for diagnosing Parrot bornaviruses, enabling sample collection when the birds are restrained for clinical evaluation. This approach facilitates a prompt and effective antemortem diagnosis, thereby serving as an efficient screening method for parrots kept in captivity.

Immunophenotype of the inflammatory response in the central and enteric nervous systems of cockatiels (Nymphicus hollandicus) experimentally infected with parrot bornavirus 2.

Proventricular dilatation disease is a lethal disease of psittacine birds. In this study, we characterized the local cellular immune response in the brain, proventriculus, and small intestine of 27 cockatiels (Nymphicus hollandicus) experimentally infected with parrot bornavirus 2 (PaBV-2). Perivascular cuffs in the brain were composed of CD3+ T-lymphocytes and Iba1+ macrophages/microglia in most cockatiels (n = 26). In the ganglia of the proventriculus, CD3+ T-lymphocytes (n = 17) and Iba1+ macrophages (n = 13) prevailed. The ganglia of the small intestine had a more homogeneous distribution of these leukocytes, including PAX5+ B-lymphocytes (n = 9), CD3+ T-lymphocytes (n = 8), and Iba1+ macrophages (n = 8). Our results indicate that perivascular cuffs in the brain and the inflammatory infiltrate in the proventriculus of PaBV-2-infected cockatiels is predominately composed of T-lymphocytes, while the inflammatory infiltrates in the ganglia of the small intestine are characterized by a mixed infiltrate composed of T-lymphocytes, B-lymphocytes, and macrophages.

Two novel bornaviruses identified in colubrid and viperid snakes.

We present the complete genome sequences of Caribbean watersnake bornavirus (CWBV) and Mexican black-tailed rattlesnake bornavirus (MRBV), which we identified in archived raw transcriptomic read data of a Caribbean watersnake (Tretanorhinus variabilis) and a Mexican black-tailed rattlesnake (Crotalus molossus nigrescens), respectively. The genomes of CWBV and MRBV have a length of about 8,900 nucleotides and comprise the complete coding regions and the untranslated regions. The overall genomic makeup and predicted gene content is typical for members of the genus Orthobornavirus within the family Bornaviridae. Alternative splicing was detected for the L and M genes. Based on a phylogenetic analysis of all viral proteins, we consider both viruses to be members of a single novel species within the genus Orthobornavirus. Both viruses form a distinct outgroup to all currently known orthobornaviruses. Based on the novel virus genomes, we furthermore identified closely related endogenous bornavirus-like nucleoprotein sequences in transcriptomic data of veiled chameleons (Chamaeleo calyptratus) and a common lancehead (Bothrops atrox).

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

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.

Cardiac Lesions of Natural and Experimental Infection by Parrot Bornaviruses.

Lymphoplasmacytic inflammation associated with bornavirus N protein occurs in the epicardial ganglia, myocardium and endocardium of birds diagnosed with proventricular dilatation disease (PDD). These pathological findings suggest that sudden death in psittacine birds might stem from cardiac compromise due to parrot bornavirus (PaBV) infection. Therefore, we investigated cardiac lesions in cases of PDD, searching databases from 1988 to 2019, and reviewed three experimental studies of PaBV infection. Fifty cases of PDD in birds infected naturally with PaBV and 27 cases of PDD in birds infected experimentally with PaBV (all having descriptions of inflammatory cardiac lesions) were reviewed. For each case, five regions of the heart were evaluated by light microscopy and immunohistochemistry (IHC). These regions were the epicardial ganglia/nerves, the endocardium, the myocardium, the Purkinje fibres and the great vessels. Sudden death was documented in 17/50 naturally infected cases, while 23/50 had digestive signs, and only 12/50 had neurological signs. Grossly, only five naturally-infected and five experimentally-infected cases had cardiomegaly or hydropericardium. Epicardial ganglioneuritis was the most consistent microscopical finding in natural (46/50) and experimental cases (26/27), followed by myocarditis (34/50) for naturally-infected and endocarditis for experimentally-infected birds (6/27). PaBV-2 antigen was detected most frequently by IHC in the epicardial ganglia (54/77) compared with the other tissues. This retrospective study demonstrates the presence of PaBV protein and inflammation in the heart of birds infected with PaBV and suggests a link between PaBV and cardiac disease and sudden death in psittacine birds.

Detection of Avian Bornavirus in Wild and Captive Passeriformes in Brazil.

Avian bornaviruses (ABVs) are the causative agents of proventricular dilatation disease (PDD), a fatal neurologic disease considered to be a major threat to psittacine bird populations. We performed a reverse transcription PCR survey to detect the presence of canary avian bornavirus (CnBV) in birds of order Passeriformes related to different clinical manifestations, such as sudden death, neurologic signs, apathy, anorexia, excessive beak growth, and PDD. A total of 227 samples from captive and wild canaries were included, of which 80 samples were captive birds, comprising saffron finches (n = 71) and common canary (n = 9), and 147 samples were wild birds distributed among a variety of several species. Two samples from captive birds (2/80) were positive for ABV, and in wild birds, only one sample was positive for ABV. The positive samples were subjected to DNA sequencing, and only the CnBV-1 serotype was found, which was the first time it was detected outside of Germany (Austria/Hungary), where it was first detected in 2009. Phylogenetic analysis confirmed that avian bornavirus serotype CnBV-1 is present in order Passeriformes in Brazil.

Detección de bornavirus aviar en aves paseriformes silvestres y en cautiverio en Brasil. Los bornavirus aviares (ABV, por sus siglas en inglés) son los agentes causantes de la enfermedad de la dilatación proventricular (PDD), una enfermedad neurológica mortal considerada como una de las principales amenazas para las poblaciones de aves psitácidas. Se realizó un muestreo por transcrpción reversa y PCR para detectar la presencia de bornavirus de los canarios (CnBV) en aves de orden Passeriformes relacionadas con diferentes manifestaciones clínicas, como muerte súbita, signos neurológicos, apatía, anorexia, crecimiento excesivo del pico y enfermedad de dilatación proventricular. Se incluyeron un total de 227 muestras de canarios en cautividad y silvestres, de las cuales 80 muestras fueron de aves en cautiverio, incluyendo jilgueros dorados (n =71) y canarios comunes (n = 9) y 147 muestras fueron aves silvestres distribuidas entre una variedad de especies. Dos muestras de aves cautivas (2/80) fueron positivas para bornavirus aviar; en aves silvestres, solo una muestra fue positiva para bornavirus aviar. Las muestras positivas se sometieron a secuenciación de ADN y solo se encontró el bornavirus de canarios serotipo 1, que es la primera vez que se detecta fuera de Alemania (Austria/Hungría), donde se detectó por primera vez en el año 2009. El análisis filogenético confirmó que el bornavirus de canarios serotipo 1 está presente en el orden Passeriformes en Brasil.

[Crazy horse disease]. / La enfermedad de los caballos locos.

With the apparition of the crazy cows disease at the end of twentieth century, great was the temptation for denominate "crazy horses disease" an ancient enzootic encephalo-myelitis, known from the 17th century and now named "Borna disease" in 1970, because severe outbreaks affecting horses in this city of Germany since 1885. But the sickness was not a prion disease but a viral one, causing also encephalopathy in several other animal species. After seventy years of investigation, the finding of the virus in human patients with psychiatric pathology in the eighties gave an incentive to work harder, and the genome structure of the so called Bornavirus was completely described. Recently, japanese investigators found that elements homologous to the nucleoprotein (N) gene of Bornavirus exist in the genomes of several mammalian species, including humans, in which these sequences have been designated endogenous Borna-like N (EBLN) elements. And now the question is what they are doing there since their integration two million years ago.

La enfermedad de los caballos locos / Crazy horse disease

Resumen Con la aparición de la enfermedad de las vacas locas a finales del siglo XX, nació la tentación de llamar enfermedad de los caballos locos a una Antigua enzootia alemana, una encéfalo-mielietis conocida desde el siglo XVII y desde 1970 llamada "enfermedad de Borna", a causa de severos brotes afectando a los caballos en esa ciudad de la Sajonia desde 1885. Como los animales caminaban en círculos, cruzaban las patas, se veían lentos y estúpidos y parecían experimentar fuerte cefalea, algunos observadores ignorantes, entonces y ahora, pudieron pensar que estos caballos estaban locos. Más, no era una encefalitis espongiforme causada por un prion, sino una infección viral que podía afectar a varias especies animales. Después de setenta años de investigación en busca del agente causal, la aparición de las vacas locas motivó a los investigadores a darse prisa, que se hizo frenética al encontrar el virus en pacientes humanos afectados por diversas patologías psiquiátricas en los años ochenta, hasta llegar a la completa secuenciación del ahora llamado Bornavirus. No terminaba de rechazarse por completo su rol en estas patologías, cuando investigadores japoneses encontraron elementos homólogos al gen de la nucleoproteína N del virus en el genoma de varias especies de mamíferos, incluyendo la humana. Designadas estas secuencias como elementos endógenos Borna-like N (EBLN), que se habrían integrado a nuestro genoma hace dos millones de años, la pregunta que surge es… ¿qué han estado haciendo allí durante tanto tiempo?

With the apparition of the crazy cows disease at the end of twentieth century, great was the temptation for denominate "crazy horses disease" an ancient enzootic encephalo-myelitis, known from the 17th century and now named "Borna disease" in 1970, because severe outbreaks affecting horses in this city of Germany since 1885. But the sickness was not a prion disease but a viral one, causing also encephalopathy in several other animal species. After seventy years of investigation, the finding of the virus in human patients with psychiatric pathology in the eighties gave an incentive to work harder, and the genome structure of the so called Bornavirus was completely described. Recently, japanese investigators found that elements homologous to the nucleoprotein (N) gene of Bornavirus exist in the genomes of several mammalian species, including humans, in which these sequences have been designated endogenous Borna-like N (EBLN) elements. And now the question is what they are doing there since their integration two million years ago.

Proventricular dilatation disease (PDD) outbreak in blue-and-gold macaws (Ara ararauna) in the State of Santa Catarina, southern Brazil / Surto de doença da dilatação proventricular em araras-canindé (Ara ararauna) no estado de Santa Catarina, sul do Brasil

Proventricular dilatation disease (PDD) is a lethal and important disease of captive psittacine birds, and affects a wide range of species, including endangered ones, and lacks an effective treatment. This report describes PDD in three blue-and-gold macaws (Ara ararauna) in southern Brazil. All three macaws originated from the same aviary and presented similar clinical signs including anorexia, apathy, emaciation and prostration. At necropsy, one of the macaws presented an enlarged proventriculus. Histologically, lymphoplasmacytic infiltrates was observed in the ganglia and nerves of the esophagus, crop, proventriculus, ventriculus, heart, adrenal glands, and adrenal medulla of all three cases. Two macaws had meningoencephalomyelitis and one had myocarditis. Immunohistochemistry identified PaBV antigen in the brain, proventricular, ventricular ganglia, and epicardial ganglia, and cardiomyocytes of all three macaws.(AU)

A doença da dilatação proventricular (PDD) e uma importante e fatal doença de psitacídeos de cativeiro, que afeta uma grande variedade de espécies e não tem um tratamento efetivo até o momento. Este relato descreve PDD em três araras canindé (Ara ararauna) no sul do Brasil. Todas as três araras eram provenientes do mesmo criatório e apresentaram sinais clínicos semelhantes incluindo anorexia, apatia, emaciação e prostração. Na necropsia, uma das araras apresentou proventrículo dilatado. No exame histopatológico, infiltrados linfoplasmacitários foram observados em gânglios e nervos do esôfago, inglúvio, proventrículo, moela, coração, glândulas adrenais e rins de todos os casos. Adicionalmente, meningoencefalomielite foi observada em duas araras e miocardite em uma. A imuno-histoquímica identificou antígenos de PaBV no encéfalo, coração, proventrículo e moela de todos os casos.(AU)

Proventricular dilatation disease (PDD) outbreak in blue-and-gold macaws (Ara ararauna) in the State of Santa Catarina, southern Brazil / Surto de doença da dilatação proventricular em araras-canindé (Ara ararauna) no estado de Santa Catarina, sul do Brasil

Proventricular dilatation disease (PDD) is a lethal and important disease of captive psittacine birds, and affects a wide range of species, including endangered ones, and lacks an effective treatment. This report describes PDD in three blue-and-gold macaws (Ara ararauna) in southern Brazil. All three macaws originated from the same aviary and presented similar clinical signs including anorexia, apathy, emaciation and prostration. At necropsy, one of the macaws presented an enlarged proventriculus. Histologically, lymphoplasmacytic infiltrates was observed in the ganglia and nerves of the esophagus, crop, proventriculus, ventriculus, heart, adrenal glands, and adrenal medulla of all three cases. Two macaws had meningoencephalomyelitis and one had myocarditis. Immunohistochemistry identified PaBV antigen in the brain, proventricular, ventricular ganglia, and epicardial ganglia, and cardiomyocytes of all three macaws.(AU)

A doença da dilatação proventricular (PDD) e uma importante e fatal doença de psitacídeos de cativeiro, que afeta uma grande variedade de espécies e não tem um tratamento efetivo até o momento. Este relato descreve PDD em três araras canindé (Ara ararauna) no sul do Brasil. Todas as três araras eram provenientes do mesmo criatório e apresentaram sinais clínicos semelhantes incluindo anorexia, apatia, emaciação e prostração. Na necropsia, uma das araras apresentou proventrículo dilatado. No exame histopatológico, infiltrados linfoplasmacitários foram observados em gânglios e nervos do esôfago, inglúvio, proventrículo, moela, coração, glândulas adrenais e rins de todos os casos. Adicionalmente, meningoencefalomielite foi observada em duas araras e miocardite em uma. A imuno-histoquímica identificou antígenos de PaBV no encéfalo, coração, proventrículo e moela de todos os casos.(AU)

Survey of bornaviruses in pet psittacines in Brazil reveals a novel parrot bornavirus.

Avian bornaviruses are the causative agents of proventricular dilatation disease (PDD), a fatal neurological disease considered to be a major threat to psittacine bird populations. We performed a survey of the presence of avian bornaviruses and PDD in pet psittacines in Brazil and also studied PDD's clinical presentation as well as the genomic variability of the viruses. Samples from 112 psittacines with clinical signs compatible with PDD were collected and tested for the presence of bornaviruses. We found 32 birds (28.6%) positive for bornaviruses using reverse transcriptase polymerase chain reaction (RT-PCR). Twenty-one (65.6%) of the 32 bornavirus-positive birds presented neurological signs, seven (21.9%) presented undigested seeds in feces, four (12.5%) showed proventricular dilatation, six (18.8%) regurgitation, three (9.4%) feather plucking and three (9.4%) sudden death. The results confirm that avian bornaviruses are present in pet psittacines in Brazil, and sequence analysis identified a distinct virus, named parrot bornavirus 8 (PaBV-8).

Avian bornavirus in free-ranging psittacine birds, Brazil.

Avian bornavirus (ABV) has been identified as the cause of proventricular dilatation disease in birds, but the virus is also found in healthy birds. Most studies of ABV have focused on captive birds. We investigated 86 free-ranging psittacine birds in Brazil and found evidence for natural, long-term ABV infection.

Fatal proventricular dilatation disease in captive native psittacines in Brazil.

An outbreak of proventricular dilatation disease (PDD), a fatal inflammatory disease of psittacines (Aves: Psittaciformes), is described in native Brazilian psittacines. Twenty captive psittacines that died of suspected PDD were necropsied and 10 were submitted to histopathology, reverse transcriptase PCR (RT-PCR), and immunohistochemistry (IHC) for avian bornavirus (ABV). Examined species were one pileated parrot (Pionopsitta pileata), three vinaceous-breasted parrots (Amazona vinacea), two blue-winged macaws (Primolius maracana), one scarlet macaw (Ara macao), one chestnut-fronted macaw (Ara severa), one scaly-headed parrot (Pionus maximiliani), and one red-browed Amazon parrot (Amazona rhodocorytha). Gross examination and histopathology revealed typical PDD lesions in all birds. The presence of ABV was confirmed in four psittacines including one red-browed Amazon parrot, one blue-winged macaw, one scarlet macaw, and one chestnut-fronted macaw. In the red-browed Amazon parrot and in one blue-winged macaw, IHC demonstrated ABV antigens in the nucleus and cytoplasm of cells in various organs. This is the first description of PDD by ABV in Brazilian psittacines and indicates the necessity for adopting a strategic control plan for reducing its impact in native birds.