Newcastle disease outbreaks in fowl in Great Britain during 1984

During February to July 1984, 23 outbreaks of Newcastle disease were confirmed in chickens in Great Britain. Use of available mouse monoclonal antibodies enabled unequivocal identification of the virus responsible for 22 of the outbreaks as similar to the avian paramyxovirus type 1 (A/PMV-1) virus causing neurotropic disease in pigeons during 1983 and 1984. Epidemiological investigations presented evidence that 19 of these outbreaks occurred either directly or indirectly as a result of spread from diseased pigeons infesting food stores at Liverpool docks. Virus was isolated from carcases of pigeons found among the food and samples of the food itself. The remaining outbreak was shown to involve a virus unrelated to the virus infecting pigeons.     

Biological and molecular characterization of a pigeon paramyxovirus type-1 isolate found in Argentina

In this report, we describe the biological and molecular characterization of a paramyxovirus type-1 (PPMV-1) isolate found in wild pigeons in an urban habitat in Buenos Aires, Argentina. Of the nine pigeons captured, three were moribund, and the other six showed diarrhea, ataxia, tremor, torticolis, and wing paralysis. The intracerebral pathogenicity index was 1.29, and the amino acid (aa) sequence at the fusion protein cleavage site was 112GRQ KRF117. These characteristics correspond to a virulent Newcastle disease virus isolate. Nevertheless, it was not possible to reproduce the disease in chickens experimentally although the chickens exhibited seroconversion after inoculation. On the other hand, pigeons inoculated with the isolate became sick. These results provide further evidence about the unusual pathogenicity of PPMV-1 for chickens and show once more the need for more biological determinations in these cases to arrive at a final conclusion.     

An occurrence of Newcastle disease in pigeons: Virological and serological studies on the isolatesFoyers de maladie de Newcastle chez le pigeon: Etudes virologiques et serologiques sur des souches isolees

The antigenic and pathogenetic relationship between pigeon Newcastle disease virus (NDV) isolates during outbreaks of 1982 in Italy and reference pathogen and non-pathogen NDV-strains were investigated.The pigeon-isolates were slow-eluters and showed a thermostability at 56°C of over 30 min. They proved to be lentogenic as measured by the mean-death-time in chicken-embryos, and between lentogenic and mesogenic as measured by the Hanson test. They failed to produce plaques in chicken-embryo-fibroblasts and showed high pathogenicity for experimentally infected pigeons, low-pathogenicity for quails and were not pathogenic for chickens. They were antigenically different from the LaSota strain as measured by the cross-HI-test and induced considerable seroconversion in inoculated animals. The existence of a lentogenic neurotropic pigeon-pathogenic strain was considered.     

鸽新城疫病毒野毒PB9601株的致病性研究

用不同方法测试了从新城疫患鸽分离到的新城疫病毒（ＮＤＶ）野毒ＰＢ９６０１株的致病性。结果,该毒株对１日龄ＳＰＦ雏鸡的脑内接种致病指数为２．００,对６周龄ＳＰＦ鸡静脉接种致病指数为０．００;该毒株对６周龄左右鸽有很强的致病性,有的血清中已有一定量的抗鸽ＮＤＶ抗体;经ＳＰＦ鸡胚传１３代的尿囊液病毒对鸽的半数致死量约为１２个ＴＣＩＤ５０。由此认为,ＰＢ９６０１株ＮＤＶ是对鸡致病性很弱但对鸽呈高度致病性的毒株,可作为国内鸽ＮＤＶ强毒的参考株。     

Experimental pathogenesis for chickens, turkeys, and pigeons of exotic Newcastle disease virus from an outbreak in California during 2002-2003

Exotic Newcastle disease virus (NDV) isolated from chickens during the 2002-2003 California outbreak (CA exotic Newcastle disease [END] virus) was inoculated into 4-week-old specific-pathogen-free (SPF) White Leghorn chickens, 3-week-old SPF Beltsville White turkeys, 6-week-old commercial Broad Breasted White turkeys, and 10- to 20-week-old racing pigeons, and the clinicopathologic features of disease were compared. Birds were monitored clinically and euthanized sequentially with collection of tissues. Tissues were examined by histopathology, by immunohistochemistry to detect viral nucleoprotein, and by in situ hybridization to detect viral mRNA. Clinically, infected chickens and SPF turkeys showed severe depression, and all died or were euthanized because of severe clinical signs by day 5 postinoculation. In these birds, histologic lesions were widespread and virus was detected in multiple organs. All infected commercial turkeys showed mild depression, and incoordination was observed in some birds. Histologic lesions were mild, and viral distribution was limited. In pigeons, only 1 bird showed overt clinical disease, and histologic lesions and viral distribution were present in limited organs. Consequently, susceptibility to highly virulent NDV was shown to vary among chickens, SPF turkeys, commercial turkeys, and pigeons. Additionally, we have evidence of CA END virus subclinical infections that suggest pigeons could be subclinical carriers of other virulent NDV.     

Limited susceptibility of pigeons experimentally inoculated with H5N1 highly pathogenic avian influenza viruses

An experimental infection study was performed using pigeons reared for racing or meat production in Japan and clade 2.2 and 2.3.2 isolates of H5N1 highly pathogenic avian influenza virus to evaluate the possible role of pigeons in virus transmission to poultry. In experiment 1, when 20 pigeons were intranasally inoculated with high or low viral doses, no inoculated pigeon exhibited clinical signs for 14 days. Drinking water and almost all swab samples were negative for virus isolation. Virus isolation was positive in 3 oral swab samples from 2 pigeons from day 2 through 4 postinoculation, but viral titers of positive samples were extremely low. Immunohistochemical analysis for virus detection was negative in all tissue samples. Along with seroconversion in a limited number of pigeons postinoculation, these results suggest that pigeons have limited susceptibility to the virus used for experimental infection. In experiment 2, when uninoculated chickens were housed with virus-inoculated pigeons, all pigeons and contact chickens survived for 14 days without exhibiting any clinical signs. According to serological analysis, the chickens did not exhibit seroconversion after close contact with inoculated pigeons. Our data suggest that the risk posed by pigeons with respect to the transmission of the H5N1 highly pathogenic avian influenza virus to poultry would be less than that for other susceptible avian species.     

Characteristics of paramyxoviruses isolated from pigeons in Czechoslovakia

Nine strains of paramyxovirus isolated from racing pigeons in southern Bohemia, Moravia and western Slovakia in 1983 were identified by the haemagglutination-inhibition test with antisera to seven types of paramyxovirus and three types of influenza A virus as PMV-1, Newcastle disease virus, in all cases. The haemagglutination activity and pathogenicity of the isolates for chicken embryos, chicken fibroblast cultures, and chickens of different age were determined. The mean death time of chicken embryos (MDT/MLD) was 52.8 to 95.4 h, the average being 75.7 h. The intracerebral pathogenicity index (ICPI8) was on an average 1.42 +/- 0.10 (P = 0.95). Experimental infection of chickens at the age of one, two, three and eight weeks did not cause any clinical disease but increased the level of haemagglutination-inhibiting (HI) serum antibodies up to 1 : 256 within three weeks. The course of heat inactivation of pigeon viruses at the temperature of 56 degrees C was practically identical with the inactivation of the velogenic viscerotropic strain California/1082/71. On the basis of the results, the pigeon isolates may be considered the Newcastle disease virus of velogenic viscerotropic type whose pathogenicity for chickens has been reduced to the level of mesogenic strains by long-time passaging in pigeons.     

Identification of a strain of infectious bursal disease virus isolated from mosquitoes.

The Becht strain of infectious bursal disease virus was compared with a virus isolated from Aedes vexans mosquitoes and designed 743 virus. The viruses were compared with respect to cell culture host range, cellular changes resulting from viral infections, growth curves, antigenic relationship, and physicochemical characteristics. The viruses are closely comparable in all these properties, and they are considered to be strains of the same virus. In cross comparisons by the enzyme-linked immunosorbent assay, 743 virus and infectious bursal disease virus were found to be antigenically identical, confirming the results of the neutralization test. The 743 virus differs from most strains of infectious bursal disease virus in that it is nonpathogenic for chickens.     

Neurotropism of highly pathogenic avian influenza virus A/chicken/Indonesia/2003 (H5N1) in experimentally infected pigeons (Columbia livia f. domestica)

This investigation assessed the susceptibility of experimentally infected pigeons to the highly pathogenic avian influenza virus (HPAIV) H5N1 that caused recent outbreaks of avian influenza in birds and humans in several countries of Asia. For this purpose 14 pigeons were infected ocularly and nasally with 10(8) EID50 and clinical signs were recorded and compared with five chickens infected simultaneously as positive controls. The chickens demonstrated anorexia, depression, and 100% mortality within 2 days postinoculation. Three of the pigeons died after a history of depression and severe neurological signs consisting of paresis to paralysis, mild enteric hemorrhage, resulting in a mortality of 21%. Gross lesions in these pigeons were mild and inconsistent. Occasionally subcutaneous hyperemia and hemorrhage and cerebral malacia were observed. Microscopic lesions and detection of viral antigen were confined to the central nervous system of these pigeons. In the cerebrum and to a minor extent in the brain stem a lymphohistiocytic meningoencephalitis with disseminated neuronal and glial cell necrosis, perivascular cuffing, glial nodules, and in one bird focally extensive liquefactive necrosis could be observed. The remaining nine pigeons showed neither clinical signs nor gross or histological lesions associated with avian influenza, although seroconversion against H5 indicated that they had been infected. These results confirm that pigeons are susceptible to HPAIV A/chicken/Indonesia/2003 (H5N1) and that the disease is associated with the neurotropism of this virus. Although sentinel chickens and most pigeons did not develop disease, further experiments have to elucidate whether or not Columbiformes are involved in transmission and spread of highly pathogenic avian influenza.     

Characterization of Newcastle disease virus (avian paramyxovirus-1) isolated from pigeons

Newcastle disease virus (avian paramyxovirus-1) was isolated from pigeons in 12 states between May 1984 and December 1985. One of the isolates was from a feral pigeon; the remainder were from privately owned pigeon lofts. Use of monoclonal antibodies showed seven of the eight isolates tested to be indistinguishable from the 1982 and 1983 Great Britain and European isolates. Clinical signs were paralysis, torticollis, tremors, incoordination, and death. Pigeons inoculated with the paramyxovirus-1 isolates intravenously or intramuscularly developed clinical disease identical to that described for natural infection; however, only one pigeon inoculated intranasally developed clinical signs. The mean death time for inoculated pigeons was 9.5 days, with a range of 4 to 25. Virus was shed for up to 20 days. Primary lesions observed on necropsy were gastroenterocolitis and pancreatic necrosis. Chickens experimentally infected by the cloacal, intranasal, or caudal thoracic air-sac route remained healthy. However, the intracerebral pathogenicity index (ICPI) in day-old chickens was similar to that observed with velogenic Newcastle disease virus isolates. Four of six isolates inoculated intravenously into 6-week-old chickens induced neurotropic disease.     

Isolation of a monoclonal antibody with specificity for commonly employed vaccine strains of Newcastle disease virus

A monoclonal antibody, AVS-I, was produced from a hybridization of murine myeloma cells and splenocytes from mice immunized with the La Sota strain of Newcastle disease virus (NDV). The hybridoma producing AVS-I, selected from 184 NDV-positive supernatants, is one of two supernatants that reacted exclusively with lentogenic strains in an indirect enzyme-linked immunosorbent assay. AVS-I can also be assayed by hemagglutination-inhibition (HI), which was used to test selected reference avian paramyxovirus (PMV) strains of types 1 to 3. NDV vaccines La Sota and B1 and field isolates from chickens, turkeys, pigeons, and cockatoos were also used as antigens. AVS-I had a high binding affinity for all La Sota and B1 strains, including vaccines. The antibody bound with a lower titer to the Australian Queensland V4 and Ulster strains, but it did not bind to the F strain, a lentogenic strain from England. AVS-I was HI-negative against the other PMV reference strains. AVS-I may be valuable for identifying field isolates antigenically similar to La Sota and B1 and rapidly differentiate those vaccine strains from more virulent viruses.     

Review of the literature on avian influenza A viruses in pigeons and experimental studies on the susceptibility of domestic pigeons to influenza A viruses of the haemagglutinin subtype H7

The scientific literature of the past century is reviewed on fowl plague (presently termed highly pathogenic avian influenza, HPAI) in pigeons. HPAI viruses cause epidemic disease outbreaks with high rates of losses in many avian species, particularily in chickens and turkeys. Also susceptible to disease are quails, guinea fowl, ducks, geese, ostriches, passerine birds, and birds of prey whereas conflicting reports on the susceptibility of the domestic pigeon exist. Based on literature reports and on own experiments, and applying as criteria for judgements clinically overt forms of disease, virus multiplication plus shedding and seroconversion, it is concluded that domestic pigeons are only partially susceptible to influenza A viruses of the haemagglutinin subtype H7. Infection of pigeons with H7 viruses results only in some of them in signs, virus shedding and seroconversion. Using the same criteria, pigeons appear to be even less susceptible to infection with influenza A viruses of the H5 subtype. Only one of five publications describe in 1/19 pigeons exposed to H5 influenza A virus depression one day before death, and only 2/19 multiplied and excreted virus, and 1/19 developed circulating antibodies. Consequently, pigeons play only a minor role in the epidemiology of H5 influenza viruses. In contrast, following infection with influenza A virus of the subtype H7 clinical signs in pigeons consist of conjunctivitis, tremor, paresis of wings and legs, and wet droppings. H7-infected pigeons multiply and excrete H7 viruses and develop circulating antibodies. Albeit of the status of infection, free-flying domestic pigeons can act as mechanical vectors and vehicles for long-distance transmission of any influenza A virus if plumage or feet were contaminated.     

Characterisation of an antigenically unusual virus responsible for two outbreaks of Newcastle disease in the Republic of Ireland in 1990.

Antigenic characterisation of two highly virulent virus isolates from outbreaks of Newcastle disease on two closely connected farms in County Monaghan, Republic of Ireland, in 1990 showed the viruses to be indistinguishable but unlike other Newcastle disease viruses so far tested. However, they appeared to be antigenically closest to avirulent viruses isolated from waterfowl from several countries and from chickens in Northern Ireland in 1986. Despite the antigenic differences, chickens vaccinated with a live commercial Hitchner B1 vaccine were protected against intramuscular challenge with one of the virulent isolates.     

鸽新城疫野毒株的分离及生物学特性研究

对分离的Ｇ１、Ｇ２、Ｇ３３株鸽新城疫病毒进行了电镜检查、致病性指数测定、血凝试验（ＨＡ）,与鸡新城疫Ｌａｓｏｔａ毒株的交叉血凝抑制试验（ＨＩ）、致病性试验。测得鸡胚半数感染量（ＥＩＤ５０）分别为１０－８．４１,１０－７．５３,１０－７．８３;鸡胚最小致死量（ＬＤ）均为１０－４;鸡胚平均致死时间（ＭＤＴ）分别为８０ｈ,９０ｈ,９６ｈ;１日龄雏鸡脑内致病指数（ＩＣＰＩ）分别为１．６０,１．５０,１．５５;分离毒株与Ｌａｓｏｔａ毒株和其相应血清的交叉凝集抑制试验有明显差异。将分离毒株分别接种１月龄鸽各３只,４～１０ｄ全部出现典型神经症状,１５ｄ内死亡。结果表明所分离的３株病毒为鸽新城疫病毒,在抗原性上与鸡新城疫病毒存在一定差异,对鸡也有一定致病力。为制定防制措施,研制鸽新城疫疫苗,控制新城疫流行提供了科学依据。     

Isolation and characterization of a coronavirus from pigeons with pancreatitis

OBJECTIVE: To identify and partially characterize a coronaviruslike virus isolated from naturally infected pigeons. ANIMALS: 50 specific pathogen-free (SPF) embryonated chicken eggs, 30 White Leghorn SPF chickens, and 12 clinically normal pigeons. PROCEDURES: Pancreatic tissue specimens from sick pigeons were inoculated into SPF embryonated chicken eggs for viral isolation and investigation of morphologic and hemagglutinating properties of the isolate, called PSH050513. Furthermore, virulence studies in SPF chickens and experimental pigeons were performed. The spike (S) glycoprotein gene of PSH050513 was further sequenced and analyzed. RESULTS: PSH050513 was isolated and identified from the experimentally infected pigeons by a routine method, which was in accordance with Koch's postulates. The complete S protein (1,167 amino acids) was compared with published S protein sequences of other avian and mammalian coronaviruses. A high degree of sequence identity (79.3% to 99.6%) was observed between the S protein sequence of PSH050513 and published sequences of avian infectious bronchitis virus (IBV); only limited identity (< 37.8%) was observed with turkey coronavirus and mammalian coronaviruses. Furthermore, when the virus was inoculated into SPF chickens, pancreatitis developed. CONCLUSIONS AND CLINICAL RELEVANCE: PSH050513 has been tentatively identified as a novel member of group 3 coronaviruses that have close genetic relationships with IBV strains.     

A vaccine prepared from a non-pathogenic H5N1 influenza virus strain from the influenza virus library conferred protective immunity to chickens against the challenge with antigenically drifted highly pathogenic avian influenza virus

Inactivated influenza virus vaccine prepared from a non-pathogenic influenza virus strain A/duck/Hokkaido/Vac-1/2004 (H5N1) from the virus library conferred protective immunity to chickens against the challenge of antigenically drifted highly pathogenic avian influenza virus (HPAIV), A/whooper swan/Hokkaido/1/2008 (H5N1). The efficacy of the vaccine was comparable to that prepared from genetically modified HPAIV strain deltaRRRRK rg-A/ whooper swan/Mongolia/3/2005 (H5N1), which is more antigenically related to the challenge virus strain, in chickens.     

2株鸽源新城疫病毒的毒力鉴定和基因型分析

2008年从临床鸽病例中分离到2株新城疫病毒毒株,经测定,鸡胚平均死亡时间(MDT)分别为48h和46h,8周龄SPF鸡静脉接种指数(IVPI)分别为2.88和2.91,一日龄雏鸡脑内接种指数(IPCI)分别为1.88和1.89,按照OIE推荐的标准均为强毒株。RT-PCR扩增出融合蛋白(F)基因片段,测序,推导的氨基酸序列中蛋白酶裂解位点附近的氨基酸序列均符合强毒特征序列。根据F蛋白的部分基因序列绘制的系统进化发生树和F基因片段中3种限制性内切酶(RE)位点分布判定这2个毒株均为基因Ⅶc型。     

Protection levels of vaccinated pigeons (<Emphasis Type="Italic">Columba livia)</Emphasis> against a highly pathogenic newcastle disease virus strain

The purposes of this study were to model a vaccination regimen for Newcastle disease virus (NDV) in pigeons, and to evaluate the susceptibility and behavior of vaccinated birds against a highly pathogenic NDV Brazilian strain. Antibody response was assessed by means of hemagglutination inhibition test (HI), and viral genome excretion by means of RT-PCR. Vaccinal strains (La Sota and Ulster) induced high antibody titers without any adverse effects, both in inoculated and in sentinel birds. A viral strain pathogenic for chickens did not produce clinical signs of the disease in experimentally infected pigeons. Only 4 out of 10 vaccinated pigeons shed NDV genome, and just for two days. Results confirmed the high infectivity of the vaccinal strains used, as all nonvaccinated pigeons showed antibody titers as high as those of vaccinated birds.