Tracheal post-vaccinal reaction to different strains of Newcastle disease vírus / Reação traqueal pós-vacinal à diferentes cepas do vírus da doença de Newcastle

The aim of the present study was to evaluate the post-vaccinal reaction to two lentogenic vaccine strains of Newcatle disease virus (NDV) and a recombinant turkey herpesvirus (rHVT) vaccine expressing the fusion glycoprotein of NDV in broiler chickens through histomorphometric and histopathologic analyses of the trachea. The experiment involved 245 chicks housed in randomized blocks with three different enclosures under controlled conditions of temperature, light and ventilation. Each enclosure represented a vaccine strain and was divided into groups according to the administration route. Each block also had its own control group composed of unvaccinated birds. The vaccine strains PHY.LMV.42 (PL42) and La Sota (LS) were selected according to the Intracerebral Pathogenicity Index (ICPI) and the rHVT-NDV Serotype 3 strain (ST3) was selected for representing non-NDV infection. At two, four, seven, 14 and 21 days post vaccination, fragments from the middle third of the trachea were collected and submitted to routine histological processing. For the histomorphometric analysis, the slides were photographed, and the thickness of the tracheal mucosa was measured. Statistical analysis involved two-way ANOVA and Tukey's post-hoc test with a 5% significance level. For the histopathological evaluation, lesions were described as to the degree of intensity and distribution. At four and 14 days post vaccination with the LS strain administered by the ocular route, the means of thickening of the tracheal mucosa (20.85±7.31µm and 26.97±5.50µm, respectively) were significantly higher (p<0.05) than for all other strains, which was related to the severe histopathological lesions found in this group, characterized by hyperemia, hyperplasia of the mucous glands, moderate deciliation and multifocal lymphohistiocytic inflammatory infiltrate. At 21 days, broiler chickens vaccinated with the ST3 strain showed more discrete lesions and less thickening of the tracheal mucosa (23.23±7.62µm; p<0.05) in comparison with other studied strains. The lesions found in this group were only hemorrhage, deciliation and mild focal lymphocytic inflammatory infiltrate. The results of the histomorphometry and histopathology of the trachea indicated that vaccination with rHVT-NDV Serotype 3 strain induced lower degree post-vaccine tracheal lesions compared to other vaccine strains analyzed in this study.

Objetivou-se avaliar a reação pós-vacinal de duas estirpes lentogênicas do vírus da doença de Newcastle (VDN) e uma vacina recombinante de herpesvirus de perus (rHVT) que expressa a glicoproteína de fusão de VDN em frangos de corte por meio da histomorfometria e histopatologia da traqueia. Foram utilizados 245 pintos alojados em blocos ao acaso, sendo três galpões distintos em condições controladas de temperatura, luz e ventilação. Cada galpão representou uma cepa vacinal, onde foram divididos por grupos de acordo com a via de administração. Todos os blocos possuíam um grupo controle composto por aves não vacinadas. As cepas vacinais PHY.LMV.42 (PL42) e La Sota (LS) utilizadas foram selecionadas de acordo com o Índice de Patogenicidade Intracerebral (IPIC) e a cepa Sorotipo 3 (ST3), da vacina rHVT-VDN foi selecionada por não representar infecção do VDN. Aos dois, quarto, sete, 14 e 21 dias pós-vacinação, fragmentos do terço médio da traqueia foram coletados e posteriormente processados conforme rotina histológica. Para análise histomorfométrica da mucosa traqueal, as lâminas foram fotografadas e realizadas as mensurações da espessura da mucosa traqueal sendo aplicado teste de análise de variância a dois critérios (ANOVA) e utilizando o post-hoc de Tukey com nível de significância de 5%. Para a avaliação histopatológica foram observadas a presença de lesões microscópicas e estas foram descritas quanto ao grau de intensidade e distribuição. Aos quatro e quatorze dias pós-vacinação com a cepa LS administrada por via ocular, as médias do espessamento da mucosa traqueal (20,85±7,31µm e 26,97±5,50µm, respectivamente) foram significativamente maiores (p<0,05) quando comparada a todas as demais cepas utilizadas, isto se deve às severas lesões histopatológicas encontrados neste grupo, caracterizadas por hiperemia, hiperplasia das glândulas mucosas, deciliação moderada e infiltrado inflamatório linfohistiocitário multifocal moderado. Já aos 21 dias as aves vacinadas com a cepa ST3 apresentaram lesões mais discretas e menor espessamento da mucosa da traqueia (23,23±7,62µm; p<0,05) em comparação às demais cepas estudadas. As lesões encontradas neste grupo foram apenas hemorragia, deciliação e infiltrado inflamatório linfocitário focal discreto. Os resultados da histomorfometria e da histopatologia da traqueia indicou que a vacinação com a rHVT-NDV, cepa Sorotipo 3 induziu menor grau de lesões pós-vacinais na traqueia comparada a outras cepas vacinais analisadas nesse estudo.

Molecular diagnosis of avian viruses in grassland passerines and captive yellow cardinals Gubernatrix cristata in Brazil / Diagnóstico molecular de vírus aviários em passeriformes campestres e cardeais-amarelos Gubernatrix cristata cativos no Brasil

Avian influenza viruses (AIVs), Newcastle disease virus (NDV), West Nile virus (WNV), adenovirus (AV) and herpesvirus (HV) play an important role in the health of human and animal populations. However, knowledge of the prevalence of these viruses in wild birds is restricted to some groups (e.g. shorebirds) or regions worldwide. Information on grassland birds of South America, which is essential for their conservation, is scarce. The objectives of the present study were to evaluate occurrences of AIV, NDV, WNV, AV and HV for the first time in a bird community of a unique protected area in southern Brazil, which is home for the critically endangered yellow cardinal (Gubernatrix cristata), and captive yellow cardinals from fauna maintainers of the Brazilian Captive Program of the Yellow Cardinal. Passerine species of wild life were caught, identified and samples (swabs) were collected from the oropharynx and cloaca of 64 passerines of 26 species (including 3 yellow cardinals) and 30 yellow cardinals of captive, for molecular diagnosis. The samples were subjected to RNA and DNA extraction and the real-time polymerase chain reaction (RT-PCR) for AIV, NDV and WNV and nested PCR for AV and HV. One yellow cardinal of captive presented a positive result for AV, this result is important for planning, managing natural attributes and making decisions in relation to integrated conservation of threatened species. This is the first report of AV in yellow cardinal and epidemiological investigation of viruses in wild passerines of the Pampa biome, in Rio Grande do Sul, Brazil.(AU)

Os vírus da gripe aviária (VGA), vírus da doença de Newcastle (VDN), vírus do Nilo Ocidental (VNO), adenovírus (AV) e herpesvírus (HV) desempenham um papel importante na saúde das populações humana e animal. No entanto, o conhecimento da prevalência desses vírus em aves selvagens é restrito a alguns grupos (por exemplo, aves limícolas) ou regiões em todo o mundo. As informações sobre as aves campestres da América do Sul, essenciais para a sua conservação, são escassas. Os objetivos do presente estudo foram avaliar a ocorrência de VGA, VDN, VNO, AV e HV pela primeira vez em uma comunidade de aves de uma área única protegida no Sul do Brasil, que abriga o cardeal-amarelo (Gubernatrix cristata) criticamente ameaçado de extinção e em cardeais-amarelos de cativeiro dos mantenedores de fauna do Programa Brasileiro de Cativeiro do Cardeal-amarelo. Espécies de passeriformes silvestres foram capturadas, identificadas e amostras (swabs) foram coletadas da orofaringe e cloaca de 64 passeriformes de 26 espécies (incluindo 3 cardeais-amarelos) e 30 cardeais-amarelos de cativeiro, para diagnóstico molecular. As amostras foram submetidas à extração de RNA e DNA e à reação em cadeia da polimerase em tempo real (RT-PCR) para VGA, VDN e VNO e nested PCR para AV e HV. Um cardeal-amarelo de cativeiro apresentou resultado positivo para AV, este resultado é importante para o planejamento, manejo dos atributos naturais e tomada de decisões em relação à conservação integrada de espécies ameaçadas. Este é o primeiro relato de AV em cardeal-amarelo e de investigação epidemiológica de vírus em passeriformes silvestres do bioma Pampa, no Rio Grande do Sul, Brasil.(AU)

Molecular diagnosis of avian viruses in grassland passerines and captive yellow cardinals Gubernatrix cristata in Brazil / Diagnóstico molecular de vírus aviários em passeriformes campestres e cardeais-amarelos Gubernatrix cristata cativos no Brasil

Avian influenza viruses (AIVs), Newcastle disease virus (NDV), West Nile virus (WNV), adenovirus (AV) and herpesvirus (HV) play an important role in the health of human and animal populations. However, knowledge of the prevalence of these viruses in wild birds is restricted to some groups (e.g. shorebirds) or regions worldwide. Information on grassland birds of South America, which is essential for their conservation, is scarce. The objectives of the present study were to evaluate occurrences of AIV, NDV, WNV, AV and HV for the first time in a bird community of a unique protected area in southern Brazil, which is home for the critically endangered yellow cardinal (Gubernatrix cristata), and captive yellow cardinals from fauna maintainers of the Brazilian Captive Program of the Yellow Cardinal. Passerine species of wild life were caught, identified and samples (swabs) were collected from the oropharynx and cloaca of 64 passerines of 26 species (including 3 yellow cardinals) and 30 yellow cardinals of captive, for molecular diagnosis. The samples were subjected to RNA and DNA extraction and the real-time polymerase chain reaction (RT-PCR) for AIV, NDV and WNV and nested PCR for AV and HV. One yellow cardinal of captive presented a positive result for AV, this result is important for planning, managing natural attributes and making decisions in relation to integrated conservation of threatened species. This is the first report of AV in yellow cardinal and epidemiological investigation of viruses in wild passerines of the Pampa biome, in Rio Grande do Sul, Brazil.(AU)

Os vírus da gripe aviária (VGA), vírus da doença de Newcastle (VDN), vírus do Nilo Ocidental (VNO), adenovírus (AV) e herpesvírus (HV) desempenham um papel importante na saúde das populações humana e animal. No entanto, o conhecimento da prevalência desses vírus em aves selvagens é restrito a alguns grupos (por exemplo, aves limícolas) ou regiões em todo o mundo. As informações sobre as aves campestres da América do Sul, essenciais para a sua conservação, são escassas. Os objetivos do presente estudo foram avaliar a ocorrência de VGA, VDN, VNO, AV e HV pela primeira vez em uma comunidade de aves de uma área única protegida no Sul do Brasil, que abriga o cardeal-amarelo (Gubernatrix cristata) criticamente ameaçado de extinção e em cardeais-amarelos de cativeiro dos mantenedores de fauna do Programa Brasileiro de Cativeiro do Cardeal-amarelo. Espécies de passeriformes silvestres foram capturadas, identificadas e amostras (swabs) foram coletadas da orofaringe e cloaca de 64 passeriformes de 26 espécies (incluindo 3 cardeais-amarelos) e 30 cardeais-amarelos de cativeiro, para diagnóstico molecular. As amostras foram submetidas à extração de RNA e DNA e à reação em cadeia da polimerase em tempo real (RT-PCR) para VGA, VDN e VNO e nested PCR para AV e HV. Um cardeal-amarelo de cativeiro apresentou resultado positivo para AV, este resultado é importante para o planejamento, manejo dos atributos naturais e tomada de decisões em relação à conservação integrada de espécies ameaçadas. Este é o primeiro relato de AV em cardeal-amarelo e de investigação epidemiológica de vírus em passeriformes silvestres do bioma Pampa, no Rio Grande do Sul, Brasil.(AU)

Viral distribution of Newcastle disease virus genotype VII in different organs of broiler chickens

The poultry industry in Egypt is still threatened by Newcastle disease despite intensive vaccination programs. Bothvaccinated and unvaccinated poultry flocks have experienced Newcastle disease virus (NDV) genotype VII outbreakswithin the last few years. This study was performed to investigate the pathogenesis of NDV genotype VII in differentorgans of broiler chickens. Fifty, 1-day-old chicks were divided into 2 equal groups with 25 animals in each group. Group 1served as the non-infected (negative control) group, while group 2 was infected by intranasal inoculation of 0.1 mlcontaining 106 EID50 of NDV genotype VII. Three chicks were sacrificed from each group at 2, 5, and 10 days postinfection (dpi). Tissue sections from the nasal conchae, larynx, trachea, lungs, heart, kidneys, and brain were collected forhistopathology and immunohistochemistry. Quantitative RT-PCR (qRT-PCR) was also performed on the tracheal samples.The infected group showed severe respiratory signs and had greenish-colored diarrhea. Mortalities were 6, 4, 6, and 2 chicksat 5, 6, 7, and 9 dpi, respectively. Grossly, congestion of the mucosa of the trachea and larynx was recorded at 5 dpi.Histopathological examination of different organs revealed tracheitis, pneumonia, laryngitis, nephritis, brain perivascularcuffing, and neuronal degeneration. NDV antigen was detected by IHC in all examined organs except the brain. Strong viralantigen expression by IHC was observed at 5 and 7 dpi in most of the studied organs. Viral antigen expression was alsodetected in the endothelial cells of blood vessels, cilia, surface epithelium, and goblet cells of the nasal conchae, larynx, andtrachea in addition to the cytoplasm of cardiomyocytes and in the epithelium lining the renal tubules.

Viral distribution of Newcastle disease virus genotype VII in different organs of broiler chickens

The poultry industry in Egypt is still threatened by Newcastle disease despite intensive vaccination programs. Bothvaccinated and unvaccinated poultry flocks have experienced Newcastle disease virus (NDV) genotype VII outbreakswithin the last few years. This study was performed to investigate the pathogenesis of NDV genotype VII in differentorgans of broiler chickens. Fifty, 1-day-old chicks were divided into 2 equal groups with 25 animals in each group. Group 1served as the non-infected (negative control) group, while group 2 was infected by intranasal inoculation of 0.1 mlcontaining 106 EID50 of NDV genotype VII. Three chicks were sacrificed from each group at 2, 5, and 10 days postinfection (dpi). Tissue sections from the nasal conchae, larynx, trachea, lungs, heart, kidneys, and brain were collected forhistopathology and immunohistochemistry. Quantitative RT-PCR (qRT-PCR) was also performed on the tracheal samples.The infected group showed severe respiratory signs and had greenish-colored diarrhea. Mortalities were 6, 4, 6, and 2 chicksat 5, 6, 7, and 9 dpi, respectively. Grossly, congestion of the mucosa of the trachea and larynx was recorded at 5 dpi.Histopathological examination of different organs revealed tracheitis, pneumonia, laryngitis, nephritis, brain perivascularcuffing, and neuronal degeneration. NDV antigen was detected by IHC in all examined organs except the brain. Strong viralantigen expression by IHC was observed at 5 and 7 dpi in most of the studied organs. Viral antigen expression was alsodetected in the endothelial cells of blood vessels, cilia, surface epithelium, and goblet cells of the nasal conchae, larynx, andtrachea in addition to the cytoplasm of cardiomyocytes and in the epithelium lining the renal tubules.(AU)

Monitoring of Newcastle disease in poultry at migratory birds landing sites: Mangue Seco and Cacha Pregos between 2013 and 2014 / Monitoramento da doença de Newcastle em aves domésticas nos sítios de pouso de aves migratórias: Mangue Seco e Cacha Pregos entre 2013 e 2014

The poultry industry has been considered one of the most efficient agricultural activities, placing Brazil in the ranking of the largest producers of chicken meat. However, a threat to the poultry production chain is the entrance of Newcastle disease virus (NDV) in the country, which would bring huge economic and social losses. Monitoring of the virus was conducted in domestic poultry (Gallus gallus domesticus) farms on the migratory birds landing sites Mangue Seco and Cacha Pregos between 2013 and 2014 to control Newcastle disease (NCD) in these locations. Activities in health education, filling the questionnaire to define the sanitary profile of the farms, georeferenced registration and collection of blood samples, cloacal and tracheal swabs of the backyard birds were the epidemiological surveillance actions performed. A total of 133 serum samples were analyzed in Mangue Seco and 81 in Cacha Pregos. The results showed that both Mangue Seco (63.4%) and Cacha Pregos (88.9%) presented reactive animals for the NDV. The results of real-time polymerase chain reaction (RT-PCR) and viral isolation analyses were negative, proving that the domestic poultry were not eliminating the virus at the time of sample collection. The high percentage of reactive animals by indirect ELISA test in both epidemiological units studied suggests the presence of NDV circulating lentogenic strain, since there was no death registration and the birds did not have characteristic symptoms of the disease.(AU)

A avicultura tem sido considerada uma das atividades agrícolas mais eficientes, colocando o Brasil no ranking dos maiores produtores de carne de frango. No entanto, uma ameaça à cadeia produtiva da avicultura é a entrada do vírus da doença de Newcastle (NDV) no país, o que acarretaria enormes prejuízos econômicos e sociais. O monitoramento do vírus foi realizado em granjas de aves domésticas (Gallus gallus domesticus) nos locais de desembarque de aves migratórias de Mangue Seco e Cacha Pregos entre 2013 e 2014 para controlar a doença de Newcastle (DCNT) nesses locais. Atividades de educação em saúde, preenchimento de questionário para definição do perfil sanitário das fazendas, cadastro georreferenciado e coleta de amostras de sangue e swabs cloacal e traqueal de aves de quintal foram as ações de vigilância epidemiológica realizadas. Um total de 133 amostras de soro foram analisadas em Mangue Seco e 81 em Cacha Pregos. Os resultados mostraram que tanto Mangue Seco (63,4%) quanto Cacha Pregos (88,9%) apresentaram animais reativos para o NDV. Os resultados da reação em cadeia da polimerase em tempo real (RT-PCR) e das análises de isolamento viral foram negativos, comprovando que as aves domésticas não estavam eliminando o vírus no momento da coleta das amostras. O alto percentual de animais reativos pelo teste ELISA indireto em ambas as unidades epidemiológicas estudadas sugere a presença de cepa lentogênica circulante de NDV, uma vez que não houve registro de óbito e as aves não apresentavam sintomas característicos da doença.(AU)

Monitoring of Newcastle disease in poultry at migratory birds landing sites: Mangue Seco and Cacha Pregos between 2013 and 2014 / Monitoramento da doença de Newcastle em aves domésticas nos sítios de pouso de aves migratórias: Mangue Seco e Cacha Pregos entre 2013 e 2014

The poultry industry has been considered one of the most efficient agricultural activities, placing Brazil in the ranking of the largest producers of chicken meat. However, a threat to the poultry production chain is the entrance of Newcastle disease virus (NDV) in the country, which would bring huge economic and social losses. Monitoring of the virus was conducted in domestic poultry (Gallus gallus domesticus) farms on the migratory birds landing sites Mangue Seco and Cacha Pregos between 2013 and 2014 to control Newcastle disease (NCD) in these locations. Activities in health education, filling the questionnaire to define the sanitary profile of the farms, georeferenced registration and collection of blood samples, cloacal and tracheal swabs of the backyard birds were the epidemiological surveillance actions performed. A total of 133 serum samples were analyzed in Mangue Seco and 81 in Cacha Pregos. The results showed that both Mangue Seco (63.4%) and Cacha Pregos (88.9%) presented reactive animals for the NDV. The results of real-time polymerase chain reaction (RT-PCR) and viral isolation analyses were negative, proving that the domestic poultry were not eliminating the virus at the time of sample collection. The high percentage of reactive animals by indirect ELISA test in both epidemiological units studied suggests the presence of NDV circulating lentogenic strain, since there was no death registration and the birds did not have characteristic symptoms of the disease.(AU)

A avicultura tem sido considerada uma das atividades agrícolas mais eficientes, colocando o Brasil no ranking dos maiores produtores de carne de frango. No entanto, uma ameaça à cadeia produtiva da avicultura é a entrada do vírus da doença de Newcastle (NDV) no país, o que acarretaria enormes prejuízos econômicos e sociais. O monitoramento do vírus foi realizado em granjas de aves domésticas (Gallus gallus domesticus) nos locais de desembarque de aves migratórias de Mangue Seco e Cacha Pregos entre 2013 e 2014 para controlar a doença de Newcastle (DCNT) nesses locais. Atividades de educação em saúde, preenchimento de questionário para definição do perfil sanitário das fazendas, cadastro georreferenciado e coleta de amostras de sangue e swabs cloacal e traqueal de aves de quintal foram as ações de vigilância epidemiológica realizadas. Um total de 133 amostras de soro foram analisadas em Mangue Seco e 81 em Cacha Pregos. Os resultados mostraram que tanto Mangue Seco (63,4%) quanto Cacha Pregos (88,9%) apresentaram animais reativos para o NDV. Os resultados da reação em cadeia da polimerase em tempo real (RT-PCR) e das análises de isolamento viral foram negativos, comprovando que as aves domésticas não estavam eliminando o vírus no momento da coleta das amostras. O alto percentual de animais reativos pelo teste ELISA indireto em ambas as unidades epidemiológicas estudadas sugere a presença de cepa lentogênica circulante de NDV, uma vez que não houve registro de óbito e as aves não apresentavam sintomas característicos da doença.(AU)

Phylogenetic and pathotypic characterization of newcastle disease virus in Tibetan chickens, China

Chickens are considered to be potential reservoirs of Newcastle disease virus (NDV). In this study, six Newcastle disease virus strains were isolated and characterized in Tibetan chickens. The HN gene was sequenced, and phylogenetic relationship to reference strains was studied. The phylogenetic analysis demonstrated that these six isolated strains were closely related to NDV isolates of the reference strains GQ245823, KT002186, KU527561, KJ563939, AY225110, EU305607, KM056357, Y18898, GQ245832, AF077761 and lasota strain. Among them, EU305607, KJ563939 and KM056357 were isolated from India, while lasota strain came from attenuated vaccine widely used in China. Then, mean death time (MDT) and intracerebral pathogenicity index (ICPI) were used to estimate the pathogenicity of the isolates. Pathogenicity experiment showed HNH1 and HN17 to be virulent. Our results indicated that genetically diverse viruses circulate in Tibetan chickens, and based upon the phlogeographic analysis, we estimated the origin of ancestral viruses of the isolates and its sister strains located in India and China (lasota strain). It indicates the importance of continuous surveillance to enhance current understanding of the genetic evolution of the NDV strains.(AU)

Phylogenetic and pathotypic characterization of a Newcastle disease virus strain isolated from ducks and pigeons in Hubei, China

Newcastle disease is a highly contagious disease responsible for major outbreaks and considerable economic losses in the poultry industry in China. There is still little information available regarding gene characterization of the NDV, especially in ducks and pigeons. Therefore, the aim of this study was to investigate NDV isolated from ducks and pigeons in Hubei, China. In this study, three NDVs from ducks and pigeons were isolated between 2013 and 2015.The fusion protein (F) gene of the NDV isolates was sequenced and phylogenetically analyzed. The clinical signs and gross histopathological lesions were examined. Phylogenetic analysis of these strains indicated that all the sequences are classified as genotype II. The isolates shared a 112 G-R-Q-G-R-L 117motif at the F protein cleavage site, indicating that these three isolates strains are lentogenic. Necropsy and histopathology showed the typical pathological changes. It was concluded that commercial ducks and pigeons in Hubei province carry lentogenic NDV strains with regular genetic divergence, indicating that these species may act as the main reservoirs of NDV in poultry. Therefore, strategies and surveillance should be undertaken to reduce the risk of ND outbreaks.(AU)

Phylogenetic and pathotypic characterization of newcastle disease virus in Tibetan chickens, China

Chickens are considered to be potential reservoirs of Newcastle disease virus (NDV). In this study, six Newcastle disease virus strains were isolated and characterized in Tibetan chickens. The HN gene was sequenced, and phylogenetic relationship to reference strains was studied. The phylogenetic analysis demonstrated that these six isolated strains were closely related to NDV isolates of the reference strains GQ245823, KT002186, KU527561, KJ563939, AY225110, EU305607, KM056357, Y18898, GQ245832, AF077761 and lasota strain. Among them, EU305607, KJ563939 and KM056357 were isolated from India, while lasota strain came from attenuated vaccine widely used in China. Then, mean death time (MDT) and intracerebral pathogenicity index (ICPI) were used to estimate the pathogenicity of the isolates. Pathogenicity experiment showed HNH1 and HN17 to be virulent. Our results indicated that genetically diverse viruses circulate in Tibetan chickens, and based upon the phlogeographic analysis, we estimated the origin of ancestral viruses of the isolates and its sister strains located in India and China (lasota strain). It indicates the importance of continuous surveillance to enhance current understanding of the genetic evolution of the NDV strains.(AU)

Phylogenetic and pathotypic characterization of a Newcastle disease virus strain isolated from ducks and pigeons in Hubei, China

Newcastle disease is a highly contagious disease responsible for major outbreaks and considerable economic losses in the poultry industry in China. There is still little information available regarding gene characterization of the NDV, especially in ducks and pigeons. Therefore, the aim of this study was to investigate NDV isolated from ducks and pigeons in Hubei, China. In this study, three NDVs from ducks and pigeons were isolated between 2013 and 2015.The fusion protein (F) gene of the NDV isolates was sequenced and phylogenetically analyzed. The clinical signs and gross histopathological lesions were examined. Phylogenetic analysis of these strains indicated that all the sequences are classified as genotype II. The isolates shared a 112 G-R-Q-G-R-L 117motif at the F protein cleavage site, indicating that these three isolates strains are lentogenic. Necropsy and histopathology showed the typical pathological changes. It was concluded that commercial ducks and pigeons in Hubei province carry lentogenic NDV strains with regular genetic divergence, indicating that these species may act as the main reservoirs of NDV in poultry. Therefore, strategies and surveillance should be undertaken to reduce the risk of ND outbreaks.

Pathological and molecular findings of avian avulavirus type 1 outbreak in pigeons (Columba livia) of southern Brazil / Achados patológicos e moleculares da infecção por avulavirus aviário tipo 1 em pombos (Columba livia) do sul do Brasil

The Newcastle disease, caused by avian avulavirus type 1 strains (APMV-1) is an important avian disease involved into high rates of mortality and economic losses. Several outbreaks have been reported over the last 30 years in Columbiformes in different parts of the world, caused by a adapted variant strain of AAvV-1, called pigeon paramyxovirus type 1 (PPMV-1). A high mortality associated with an outbreak was analyzed in free-living pigeons (Columba livia) in a public square in Porto Alegre in Southern Brazil. A total of 24 pigeons moribund or freshly dead, within five weeks interval were submitted to necropsy, histopathological, immunohistochemical (anti-Newcastle), and RT-PCR followed by sequencing of the amplification products analysis. They presented neurological signs, non-suppurative encephalitis and encephalomyelitis, and mononuclear inflammatory infiltrate in different organs. Immunohistochemical analysis in nine pigeons tissue showed that anti-Newcastle was expressed in brain, kidney, liver and pancreas. The RT-PCR test for the M protein of Newcastle disease virus was positive in six pigeons. The differential diagnosis of Influenza, West Nile, Mycoplasma gallisepticum and Mycoplasma synoviae in all pigeons presented negative results. The sequence of amino acids in the cleavage site region of the F protein was 112RRQKRF117 classifying the strain as virulent. The phylogenetic analysis classified this virus strain into Class II and VI genotype.(AU)

A doença de Newcastle, causada por cepas de avulavirus aviário tipo 1 (AAvV-1), é uma doença de aves importante por causar altos índices de mortalidade e perdas econômicas. Vários surtos têm sido relatados ao longo de 30 anos em aves da ordem Columbiformes, em diferentes partes do mundo, causados por uma cepa variante específica de AAvV-1, denominada Pigeon paramyxovirus tipo 1 (PPMV-1). Foi analisado um surto de mortalidade em pombos domésticos (Columba livia), provenientes de uma praça pública em Porto Alegre, no Sul do Brasil. Vinte e quatro aves moribundas ou mortas foram submetidas, no intervalo de cinco semanas, ao exame de necropsia, exame histopatológico, imuno-histoquímico anti-Newcastle, RT-PCR e sequenciamento. Apresentaram sinais neurológicos, encefalite e encefalomielite não supurativas, além de infiltrado inflamatório mononuclear em diversos órgãos. Nove aves demonstraram exame imuno-histoquímico positivo em órgãos como cérebro, rim, fígado e pâncreas. Seis aves foram positivas no exame de RT-PCR para a proteína M do vírus da Doença de Newcastle. Nos exames de diagnósticos diferenciais de Influenza, West Nile, Mycoplasma gallisepticum e Mycoplasma synoviae, todas as aves testadas foram negativas. A sequência dos aminoácidos na região do sítio de clivagem da proteína foi 112RRQKRF117, classificando a cepa como virulenta. De acordo com a análise filogenética o vírus identificado foi classificado como pertencente à classe II e ao genótipo VI.(AU)

Pathological and molecular findings of avian avulavirus type 1 outbreak in pigeons (Columba livia) of southern Brazil / Achados patológicos e moleculares da infecção por avulavirus aviário tipo 1 em pombos (Columba livia) do sul do Brasil

The Newcastle disease, caused by avian avulavirus type 1 strains (APMV-1) is an important avian disease involved into high rates of mortality and economic losses. Several outbreaks have been reported over the last 30 years in Columbiformes in different parts of the world, caused by a adapted variant strain of AAvV-1, called pigeon paramyxovirus type 1 (PPMV-1). A high mortality associated with an outbreak was analyzed in free-living pigeons (Columba livia) in a public square in Porto Alegre in Southern Brazil. A total of 24 pigeons moribund or freshly dead, within five weeks interval were submitted to necropsy, histopathological, immunohistochemical (anti-Newcastle), and RT-PCR followed by sequencing of the amplification products analysis. They presented neurological signs, non-suppurative encephalitis and encephalomyelitis, and mononuclear inflammatory infiltrate in different organs. Immunohistochemical analysis in nine pigeons tissue showed that anti-Newcastle was expressed in brain, kidney, liver and pancreas. The RT-PCR test for the M protein of Newcastle disease virus was positive in six pigeons. The differential diagnosis of Influenza, West Nile, Mycoplasma gallisepticum and Mycoplasma synoviae in all pigeons presented negative results. The sequence of amino acids in the cleavage site region of the F protein was 112RRQKRF117 classifying the strain as virulent. The phylogenetic analysis classified this virus strain into Class II and VI genotype.(AU)

A doença de Newcastle, causada por cepas de avulavirus aviário tipo 1 (AAvV-1), é uma doença de aves importante por causar altos índices de mortalidade e perdas econômicas. Vários surtos têm sido relatados ao longo de 30 anos em aves da ordem Columbiformes, em diferentes partes do mundo, causados por uma cepa variante específica de AAvV-1, denominada Pigeon paramyxovirus tipo 1 (PPMV-1). Foi analisado um surto de mortalidade em pombos domésticos (Columba livia), provenientes de uma praça pública em Porto Alegre, no Sul do Brasil. Vinte e quatro aves moribundas ou mortas foram submetidas, no intervalo de cinco semanas, ao exame de necropsia, exame histopatológico, imuno-histoquímico anti-Newcastle, RT-PCR e sequenciamento. Apresentaram sinais neurológicos, encefalite e encefalomielite não supurativas, além de infiltrado inflamatório mononuclear em diversos órgãos. Nove aves demonstraram exame imuno-histoquímico positivo em órgãos como cérebro, rim, fígado e pâncreas. Seis aves foram positivas no exame de RT-PCR para a proteína M do vírus da Doença de Newcastle. Nos exames de diagnósticos diferenciais de Influenza, West Nile, Mycoplasma gallisepticum e Mycoplasma synoviae, todas as aves testadas foram negativas. A sequência dos aminoácidos na região do sítio de clivagem da proteína foi 112RRQKRF117, classificando a cepa como virulenta. De acordo com a análise filogenética o vírus identificado foi classificado como pertencente à classe II e ao genótipo VI.(AU)

Evaluation of the Viral Interference between Lentogenic Newcastle Disease Virus (Lasota) and Avian Influenza Virus (H9N2) using Real-Time Reverse Transcription Polymerase Chain Reaction in SPF Chicken

Lentogenic Newcastle disease virus (lNDV) such as Lasota strain and low pathogenicity avian influenza such as H9N2 virus are two of the most economically important viruses affecting poultry worldwide, and little attention in recent years has been paid to simultaneous infections in chickens with these two viruses for the reason that co-infection do occur but are not easily detected. In the present study, chickens were inoculated with lNDV (Lasota) and LPAIV (A/chicken/Tehran/ZMT-173/99(H9N2)) simultaneously or sequentially three days apart. Oropharyngeal and cloacal swabs were collected from chickens from 1 to 14 days after inoculation. RRT-PCR for AIV and NDV detection was performed. The rate of viral shedding was measured within 14 days. No clinical symptoms were observed during the experiment however the pattern of virus shed was different with co-infection, thus comparing the results obtained from viral shedding showed that AIV is a much stronger agent than NDV in the occurrence of viral interference. This is due to the fact that in simultaneous inoculation, AIV replication delayed and reduced NDV replication, while replication of Lasota in simultaneous or pre-inoculated inoculation could not significantly disrupt H9N2 virus replication. These findings indicate that the infection with one virus can interfere with the replication of another, modifying the pathogenesis of the viruses. So, infection of the host with both viral agents simultaneously causes higher shedding of LPAIV than lNDV in OP and CL areas. In conclusion, co-infection with LPAVI in chickens did not impact clinical signs but affected the replication dynamics of these viruses.(AU)

Evaluation of the Viral Interference between Lentogenic Newcastle Disease Virus (Lasota) and Avian Influenza Virus (H9N2) using Real-Time Reverse Transcription Polymerase Chain Reaction in SPF Chicken

Lentogenic Newcastle disease virus (lNDV) such as Lasota strain and low pathogenicity avian influenza such as H9N2 virus are two of the most economically important viruses affecting poultry worldwide, and little attention in recent years has been paid to simultaneous infections in chickens with these two viruses for the reason that co-infection do occur but are not easily detected. In the present study, chickens were inoculated with lNDV (Lasota) and LPAIV (A/chicken/Tehran/ZMT-173/99(H9N2)) simultaneously or sequentially three days apart. Oropharyngeal and cloacal swabs were collected from chickens from 1 to 14 days after inoculation. RRT-PCR for AIV and NDV detection was performed. The rate of viral shedding was measured within 14 days. No clinical symptoms were observed during the experiment however the pattern of virus shed was different with co-infection, thus comparing the results obtained from viral shedding showed that AIV is a much stronger agent than NDV in the occurrence of viral interference. This is due to the fact that in simultaneous inoculation, AIV replication delayed and reduced NDV replication, while replication of Lasota in simultaneous or pre-inoculated inoculation could not significantly disrupt H9N2 virus replication. These findings indicate that the infection with one virus can interfere with the replication of another, modifying the pathogenesis of the viruses. So, infection of the host with both viral agents simultaneously causes higher shedding of LPAIV than lNDV in OP and CL areas. In conclusion, co-infection with LPAVI in chickens did not impact clinical signs but affected the replication dynamics of these viruses.

Survey of pathogens in threatened wild red-tailed Amazon parrot (Amazona brasiliensis) nestlings in Rasa Island, Brazil

ABSTRACT The red-tailed Amazon parrot (Amazona brasiliensis) is a threatened species of psittacine bird that inhabit coastal regions of Brazil. In view of the threat of this species, the aim of this study was to perform a health evaluation in wild nestlings in Rasa Island, determining the prevalence of enterobacteria and infectious agents according to type of nest. Blood samples were collected from 64 birds and evaluated for antibodies of Chlamydia psittaci by commercial dot-blot ELISA. Cloacal and oropharyngeal swabs samples were collected from 23 birds from artificial wooden nests, 15 birds from PVC nests and 2 birds from natural nests for microbiological analysis. Swab samples were collected from 58 parrots for C. psittaci detection by PCR and from 50 nestlings for Avian Influenza, Newcastle Disease and West Nile viruses detection analysis by real-time RT-PCR. Ten bacterial genera and 17 species were identified, and the most prevalent were Escherichia coli and Klebsiella oxytoca. There was no influence of the type of nest in the nestlings microbiota. All samples tested by ELISA and PCR were negative. There is currently insufficient information available about the health of A. brasiliensis and data of this study provide a reference point for future evaluations and aid in conservation plans.(AU)

Costs of biosecurity measures in Brazilian laying hens farms in response to policies against Avian Influenza, Newcastle Disease and Salmonellosis / Custos das medidas de biosseguridade na produção brasileira de galinhas poedeiras em resposta às políticas sanitárias contra a gripe aviária, doença de Newcastle e Salmonelose

The objective of this study was to estimate costs for egg production and for implementation of biosecurity measures described by Normative Instructions No. 56/2007, No. 59/2009, No. 36/2012 and No. 10/2013 on production costs in these establishments. To attend the “National Avian Health Program” and the “National Plan for the Prevention of Avian Influenza and Control and Prevention of Newcastle Disease”, the Brazilian Ministry of Agriculture published a series of legal acts to establish the “Procedures for Register, Inspection and Control of Breeding and Commercial Avian Establishments” intensifying the measures for prevention of high economic impact illnesses in avian flocks of the country. The adaptations comprise items of structure and biosecurity procedures that aim to increase the level of isolation of the birds to maintain them with the best health status as possible. These adaptations can result in more expenses and dedication from the producers. Thus, production costs were obtained through personal interviews with 10 voluntary commercial farmers of laying hens in Limeira region, Sao Paulo State, Brazil, between June and July, 2013. The result of this study suggests that the implementation of biosecurity measures has relatively low costs when compared to the possible risks of diseases outbreaks and the consequent economic losses that justify the adoption of these practices.(AU)

O objetivo com este trabalho foi estimar os custos para produção de ovos, bem como os impactos da implementação das normas de biosseguridade descritas pelas normativas de número 56/2007, 59/2009, 36/2012, 10/2013. Visando o atendimento ao “Programa Nacional de Sanidade Avícola” e ao “Plano Nacional de Prevenção da Influenza Aviária e de Controle e Prevenção da Doença de Newcastle”, o Ministério da Agricultura publicou uma série de atos legais para estabelecer os “Procedimentos para Registro, Fiscalização e Controle de Estabelecimentos Avícolas de Reprodução e Comerciais”, intensificando as medidas para prevenção da ocorrência de enfermidades de grande impacto econômico no plantel avícola do país. As adequações englobam itens de estrutura e procedimentos de biosseguridade que visam aumentar o nível de isolamento das aves, para mantê-las com o melhor status sanitário possível. Essas exigências podem resultar em mais despesas e dedicação por parte dos produtores. Desta forma, custos de produção foram obtidos por meio de entrevistas pessoais com 10 produtores de fazendas comerciais de avicultura de postura na região de Limeira, Estado de São Paulo, Brasil, entre junho e julho de 2013. O resultado deste estudo sugere que a implantação da biosseguridade tem custo relativamente baixo frente aos possíveis riscos de enfermidades e dos prejuízos econômicos que essas enfermidades podem causar, o que justifica a adoção destas práticas.(AU)

Costs of biosecurity measures in Brazilian laying hens farms in response to policies against Avian Influenza, Newcastle Disease and Salmonellosis / Custos das medidas de biosseguridade na produção brasileira de galinhas poedeiras em resposta às políticas sanitárias contra a gripe aviária, doença de Newcastle e Salmonelose

The objective of this study was to estimate costs for egg production and for implementation of biosecurity measures described by Normative Instructions No. 56/2007, No. 59/2009, No. 36/2012 and No. 10/2013 on production costs in these establishments. To attend the “National Avian Health Program” and the “National Plan for the Prevention of Avian Influenza and Control and Prevention of Newcastle Disease”, the Brazilian Ministry of Agriculture published a series of legal acts to establish the “Procedures for Register, Inspection and Control of Breeding and Commercial Avian Establishments” intensifying the measures for prevention of high economic impact illnesses in avian flocks of the country. The adaptations comprise items of structure and biosecurity procedures that aim to increase the level of isolation of the birds to maintain them with the best health status as possible. These adaptations can result in more expenses and dedication from the producers. Thus, production costs were obtained through personal interviews with 10 voluntary commercial farmers of laying hens in Limeira region, Sao Paulo State, Brazil, between June and July, 2013. The result of this study suggests that the implementation of biosecurity measures has relatively low costs when compared to the possible risks of diseases outbreaks and the consequent economic losses that justify the adoption of these practices.

O objetivo com este trabalho foi estimar os custos para produção de ovos, bem como os impactos da implementação das normas de biosseguridade descritas pelas normativas de número 56/2007, 59/2009, 36/2012, 10/2013. Visando o atendimento ao “Programa Nacional de Sanidade Avícola” e ao “Plano Nacional de Prevenção da Influenza Aviária e de Controle e Prevenção da Doença de Newcastle”, o Ministério da Agricultura publicou uma série de atos legais para estabelecer os “Procedimentos para Registro, Fiscalização e Controle de Estabelecimentos Avícolas de Reprodução e Comerciais”, intensificando as medidas para prevenção da ocorrência de enfermidades de grande impacto econômico no plantel avícola do país. As adequações englobam itens de estrutura e procedimentos de biosseguridade que visam aumentar o nível de isolamento das aves, para mantê-las com o melhor status sanitário possível. Essas exigências podem resultar em mais despesas e dedicação por parte dos produtores. Desta forma, custos de produção foram obtidos por meio de entrevistas pessoais com 10 produtores de fazendas comerciais de avicultura de postura na região de Limeira, Estado de São Paulo, Brasil, entre junho e julho de 2013. O resultado deste estudo sugere que a implantação da biosseguridade tem custo relativamente baixo frente aos possíveis riscos de enfermidades e dos prejuízos econômicos que essas enfermidades podem causar, o que justifica a adoção destas práticas.

Experimental infection with Brazilian Newcastle disease virus strain in pigeons and chickens

This study was designed with the goal of adding as much information as possible about the role of pigeons (Columba livia) and chickens (Gallus gallus) in Newcastle disease virus epidemiology. These species were submitted to direct experimental infection with Newcastle disease virus to evaluate interspecies transmission and virus-host relationships. The results obtained in four experimental models were analyzed by hemagglutination inhibition and reverse transcriptase polymerase chain reaction for detection of virus shedding. These techniques revealed that both avian species, when previously immunized with a low pathogenic Newcastle disease virus strain (LaSota), developed high antibody titers that significantly reduced virus shedding after infection with a highly pathogenic Newcastle disease virus strain (São Joao do Meriti) and that, in chickens, prevent clinical signs. Infected pigeons shed the pathogenic strain, which was not detected in sentinel chickens or control birds. When the presence of Newcastle disease virus was analyzed in tissue samples by RT-PCR, in both species, the virus was most frequently found in the spleen. The vaccination regimen can prevent clinical disease in chickens and reduce viral shedding by chickens or pigeons. Biosecurity measures associated with vaccination programs are crucial to maintain a virulent Newcastle disease virus-free status in industrial poultry in Brazil. (AU)

Serological Detection of Newcastle Disease Virus Antibodies in Local Chickens and Guinea Fowls in the Area of Kumasi, Ghana

Newcastle Disease (ND) has been identified as a major constraint to local poultry production with its impact being felt more in rural poultry production which forms about 80% of Ghana poultry population. However documented evidence on ND virus activity in rural poultry in Ghana is still lacking. Hence, this study was conducted to evaluate the level of circulating antibodies against ND using the Haemagglutination Inhibition (HI) technique. Sera collected from unvaccinated 292 chickens and 153 guinea fowls randomly selected from households and a live bird market in Kumasi and its environs were evaluated for Newcastle disease virus antibodies. Results showed 81.8 % (239/292) of local chickens and 24.2 % (37/153) of guinea fowls tested positive for ND antibodies. Comparison was made between the seroprevalence of ND antibodies in household and live bird market as well as between sexes. Significantly higher prevalence rate (p 0.05) was observed with chickens sampled from households compared to those from the live bird market. Higher ranges of titers were also observed in chickens from households than those from live bird markets. The presence of ND antibodies in these unvaccinated local chickens and guinea fowls indicated the presence of the virus amongst the rural poultry population, hence aneed for improvement in vaccine campaignand delivery against ND for rural poultry especially with the use of thermostable and improved oral or feed-based vaccine delivery systems.