Showing papers on "Newcastle disease published in 1992"

Protection of Chickens From Newcastle and Marek's Diseases With a Recombinant Herpesvirus of Turkeys Vaccine Expressing the Newcastle Disease Virus Fusion Protein

Abstract: Recombinant strains of herpesvirus of turkeys (HVT) were constructed that contain either the fusion protein gene or the hemagglutinin-neuraminidase gene of Newcastle disease virus (NDV) inserted into a nonessential gene of HVT. Expression of the NDV antigens was regulated from a strong promoter element derived from the Rous sarcoma virus long terminal repeat. Recombinant HVT strains were stable and fully infectious in cell culture and in chickens. Chickens receiving a single intra-abdominal inoculation at 1 day of age with recombinant HVT expressing the NDV fusion protein had an immunological response and were protected (> 90%) against lethal intramuscular challenge at 28 days of age with the neurotropic velogenic NDV strain Texas GB. Recombinant HVT expressing the NDV hemagglutinin-neuraminidase provided partial protection (47%) against the same challenge. Chickens vaccinated with recombinant HVT vaccines had low levels of protection against NDV replication in the trachea when challenged ocularly. Recombinant HVT vaccines and the parent HVT strain provided similar levels of protection to chickens challenged with the very virulent RB1B strain of Marek's disease virus, indicating that insertion of foreign sequences into the HVT genome did not compromise the ability of HVT to protect against Marek's disease.

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

Abstract: 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.

Evaluation of a modified-live virus vaccine administered in ovo to protect chickens against Newcastle disease.

Abstract: The B1 strain of Newcastle disease virus (NDV-B1), which is nonpathogenic for newly hatched chickens, killed embryos when it was used to inoculate chicken eggs at embryonation day 18. Treatment of NDV-B1 with an alkylating agent, ethylmethane sulfonate (EMS) markedly reduced the pathogenicity of the virus for 18-day-old chicken embryos. Eggs inoculated with the modified virus (NDV-B1-EMS) hatched, and the virus was isolated from lungs and spleen of 1-day-old chickens. The hatched chickens developed antibody to NDV and were protected against challenge exposure (at 4 weeks of age) with a highly virulent GB-Texas strain of NDV. Presence of maternal antibody to NDV in embryonating eggs did not influence the protective ability of NDV-B1-EMS, which also induced protective immunity when administered to 4-week-old chickens. The 50% protective dose of NDV-B1-EMS in maternal antibody-negative and -positive embryos was calculated to be 10.77 and 17.70 embryo 50% lethal doses, respectively. Results of the study indicated that NDV-B1-EMS may be used as an embryo vaccine to protect chickens against Newcastle disease.

Immunosuppressive effect of a highly virulent infectious bursal disease virus isolated in Japan.

Abstract: SUMMARY. The immunosuppressive effect of infectious bursal disease virus (IBDV) on vaccination against Newcastle disease (ND) was compared among 2-, 3-, and 4-week-old chickens inoculated with the highly virulent IBDV field isolate 90-11 and the reference serotype 1 strain GBF-1. In all age groups, isolate 90-11 severely suppressed antibody response to ND vaccination and protective vaccinal immunity against ND. In contrast, chickens inoculated with strain GBF-1 and vaccinated with ND vaccine were well protected from the ND virus challenge. The mitogenic response to phytohemagglutinin of splenic lymphocytes from chickens inoculated with isolate 90-11 or strain GBF-1 was significantly lower than that of uninoculated controls. There was no difference between the two inoculated groups in responsiveness, although lymphocyte depletion in the thymus was more severe in chickens inoculated with isolate 90-11 than in chickens inoculated with strain GBF-1.

Avian paramyxovirus serotype 1 (Newcastle disease virus)--infections in falcons.

Abstract: Summary From eight falcons and one pigeon which died from NDV over a period of 15 months in Dubai, United Arab Emirates, PMV-1 viruses were isolated on quail embryo cell cultures. The identification of all 9 strains were achieved with the haemagglutination inhibition test against polyclonal chicken PMV-1 antiserum, against mouse monoclonal antibodies as well as with the immunoperoxidase test. Intracerebral pathogenicity index and intravenous pathogenicity index tests were also carried out. Although the virus isolates in this study fell into two distinct groups, the overall clinical symptoms displayed by the falcons tailed to demonstrate any trends or specifity unique to a group. The isolate obtained from a pigeon was similar to the isolates from one group of the falcons and showed no identity with the pigeon variant virus.

Correlation of haemagglutination inhibition and enzyme‐linked immunosorbent assays for antibodies to Newcastle disease virus

Abstract: Summary Antibody responses of commercial broiler chickens vaccinated for Newcastle disease were assayed by haemagglutination inhibition and enzyme‐linked immunosorbent assay, and the results from the two methods compared. Three‐hundred‐and‐nineteen chickens from 37 farms were assayed. The correlation coefficient was 0.85. Analysis of individual slopes of data from the 37 farms indicated that at least eight chickens from a farm must be sampled to achieve an acceptable degree of parallelism.

Characterisation of Newcastle disease viruses isolated in India.

Abstract: Summary Eleven Newcastle disease virus (NDV) isolates obtained from outbreaks of disease in chickens (9) and Japanese quail (2) in Tamil Nadu, India were characterised in pathogenicity tests, antigenically, using mouse monoclonal antibodies (MAbs), and other established tests devised to distinguish between different strains. All 11 isolates were shown to be highly virulent for chickens. In indirect immunoperoxidase tests used to assess the ability of a panel of 28 MAbs to bind to infected cell cultures, 10 of the isolates showed an identical reaction pattern, the other isolate (No. 4) failed to react with one MAb which bound to cells infected with the other isolates. Isolates 9 was unstable at pH 3 while the other 10 were stable. All other properties were shared by the 11 isolates.

Immunization of day-old chickens against Newcastle disease.

Abstract: The avirulent Newcastle disease virus strain designated NDV-6/10, selected by B. Lomniczi at the Veterinary Medical Research Institute, Hungarian Academy of Sciences, is completely safe for day-old chickens by aerosol vaccination. Aerosol immunization using the Hungarian-made MASTERDROP generator (particle size: maximum 7 microns) caused no vaccination reactions among 206,000 chickens with different maternal antibody levels. Other vaccines given simultaneously did not significantly affect the protection elicited against Newcastle disease (ND). Almost 100% and 90% of the aerosolized chickens survived subcutaneous challenge with 10(6) LD50 NDV at 30 and 50 days old, respectively. A single immunization is sufficient for broilers; however, parent flocks should be revaccinated at 7 so 8 weeks old.

Efficacy of an inactivated aqueous-suspension Newcastle disease virus vaccine against paramyxovirus type 1 infection in young pigeons with varying amounts of maternal antibody.

Abstract: Summary Pigeons aged 3 weeks were vaccinated, subcutaneously, with an inactivated aqueous‐suspension LaSota vaccine. Irrespective of the level of maternally‐derived antibodies the single vaccination gave protection lasting 1 year as shown by resistance against an intramuscular challenge with a virulent ‘pigeon’ PMV‐1 strain.

A modified filter paper technique for serosurveillance of Newcastle disease.

Abstract: Newcastle disease (ND) poses a continuous and unresolved threat to poultry farmers. In tropical countries, with a dense population of poultry in open houses near farms, eradication of ND is difficult. Hence, vaccination is necessary to control the disease. Assessment of the post-vaccinal immune response is essential to monitor the efficacy of a vaccination schedule and of the vaccines used. This can be done by the haemagglutination-inhibition (HI) test, which is easy to perform and rapid, but large-scale serosurveillance presents some problems. These include collection of the sera, their storage and transportation to a laboratory. To overcome some of these difficulties, the use of filter paper to collect blood samples for serosurveillance has been recommended (Beard and Brugh, 1977; Brugh and Beard, 1980; Giambrone, 1981; Rivetz et al., 1985). An attempt was made to reduce the test time by modifying the fdter paper technique using Whatman No. I filter paper for collection of blood samples, Brij-35 solution for quick elution of antibody, and a micro-HI procedure to evaluate the antibody content.

Pathogenicity of two strains of Newcastle disease virus in the grey-breasted helmet guinea fowl.

Abstract: Thirty-five 6-week-old guinea fowl keets, seronegative for maternal antibodies to Newcastle disease virus, were infected with Herts strain (33/56) and Kumarov strain of Newcastle disease virus intramucularly (IM) or intranasally (IN). Clinical signs were first noticed four days post infection (PI) in the group infected IM but five days PI in the group infected IN with Herts strain of Newcastle disease virus. These clinical signs were similar in both groups and included anorexia, droopiness, huddling together, greenish diarrhoea and marked cachexia. Prominent nervous signs, including spasms of the head and neck, were observed in groups infected with Herts strain. The major gross lesions observed were emaciation with prominent keel bone, empty intestinal tract and distended gall bladder in most keets. The histological lesions were characterised by meningoencephalitis, necrosis and loss of lymphocytes from splenic and lymphoid aggregates. There was muscular degeneration and necrosis in the gizzard and mild pulmonary congestion and oedema in some keets. Neither gross or microscopic lesions were observed in keets that had received the Kumarov strain.

Nucleotide sequence of the phosphoprotein (P) gene of Newcastle disease virus (strain Beaudette C).

Abstract: The phosphoprotein, or P protein, of Newcastle disease virus is required for transcription of the viral genome (1) and is the major product of the P gene (2). The cDNA for the complete P gene of Newcastle disease virus (strain Beaudette C) was cloned and sequenced in both directions by using Bal-3 1 and restriction endonuclease subcloning. The largest open reading frame of the P gene codes for a protein of 395 amino acids with a calculated molecular weight of 42,241. The Beaudette C strain is mesogenic,

Isolation and characterisation of Newcastle disease virus strain in a feral dove (Stigmatopelia senegalensis) in Nigeria.

Abstract: An isolate of Newcastle disease virus (NDV) was obtained from a feral dove, (Stigmatopelia senegalensis). The isolate was shown to have a mean-death-time of 96 h and an intracerebral pathogenicity index of 0·10. It was immunogenic but not pathogenic for 6-week old chicks on experimental infection. Based on these observations the isolate was classified as a lentogenic strain. The role of such isolates of NDV from wild birds on the Nigerian poultry industry is discussed.

Pathogenic properties of Newcastle disease virus isolates in the Sudan.

Abstract: Six Newcastle disease virus (NDV) isolates were obtained from disease outbreaks on different poultry farms in the Sudan between 1988 and 1991. The pathogenic properties of these isolates were studied in comparison to those of strain Herts 33/56. All the isolates were similar in that they killed chicken embryos quickly, in mean death time (MDT) and embryo lethal dose 50 per cent (ELD50), had higher intracerebral pathogenicity indices (ICPI), and produced viscerotropic lesions in the infected chickens. The field isolates had the characteristics of the velogenic viscerotopic strains of NDV. The pathogenesis of infection caused by one of the isolates was studied. The virus was first detected in different organs and in oral and cloacal swabs on the third day after infection.

Relationship of common avian pathogen antibody titers in so-called chicken anemia agent (CAA)-antibody-positive chicks to titers in CAA-antibody-negative chicks.

Abstract: Antibody titers for infectious bursal disease virus (IBDV), infectious bronchitis virus, Newcastle disease virus, and reovirus from chicks with chicken anemia agent (CAA) antibodies were compared with antibody titers from their CAA-antibody-negative counterparts. These comparisons were made in 396 chickens that were 1 day, 2 weeks, 8-9 weeks, 10 weeks, 17 weeks, or 29-32 weeks old. Only one serum sample was collected from any given chick or chicken. There were no significant differences between the antibody titers at any age for any antigen, with one exception: at 29-32 weeks, the IBDV titers were higher (t = 2.62, df = 142, P less than 0.01) in chickens with CAA antibody. Although not at all likely, we believe that the observation of high IBDV antibody titers in CAA-antibody-positive chicks could have been a spurious one.

Use of enzyme linked immunosorbent assay for estimation of antibody to Newcastle disease virus

Abstract: Serum antibody assay of 1045 serum samples from birds vaccinated with Newcastle Disease vaccine by HI test and ELISA was carried out. Five hundred and twenty seven birds were challenged with virulent virus and data on HI test, ELISA and challenge test results were used for comparison. A good correlation between HI titres, ELISA absorbance and potency was observed indicating the usefulness of ELISA for potency estimation of vaccines and determination of immunization level in vaccinated flocks.

Detection of haemagglutination inhibition antibodies against Newcastle disease virus in unvaccinated indigenous chickens in Maiduguri, Borno State, Nigeria.

Abstract: An examination of 200 serum samples from unvaccinated indigenous (local) chickens in Maiduguri, Borno State (Nigeria) using the haemagglutination inhibition (HI) test showed 73 sera to be positive and 127 to be negative for antibodies against Newcastle disease virus. The highest antibody titre observed was 1:128. The prevalence rate was higher (46.9%) in adult chickens than in young chickens of less than 12 weeks (23%). Presence of HI antibodies in unvaccinated indigenous chickens indicates that these birds had contracted infection and recovered thereafter.

Differences in protection between heavy and light breeds of chickens following vaccination with Newcastle disease vaccines—a survey of data, 1971 to 1990

Abstract: Summary Data obtained over 20 years of Newcastle disease vaccine testing were statistically analyzed. The protection afforded heavy and light breeds of chickens was compared following challenge (efficacy) after vaccination with live and inactivated vaccines produced from different virus strains. Standard challenge virus was used throughout the period. The data show that the heavy breeds were significantly inferior in their protectability when compared with the light breeds. This inferiority was shown after vaccination with all types of vaccines. It is suggested that heavy and light breeds of chickens differ genetically in their acquired resistance to Newcastle disease virus, although difference in susceptibility to the virus as a pathogen cannot be ruled out entirely.

New virus nd dsb hd strain for new castle disease

Abstract: A heat resistant vaccine against newcastle disease is prepd. by (a) keeping hen newcastle disease B1 virus in 50-60 deg.C water bath, (b) diluting the B1 virus and innoculating into embryonted hen's egg. (c) culturing the innoculated egg in incubator, (d) collecting the cultured virus, ND DSB HP strain and (e) culturing the obtd. ND DSB HP strain. The vaccine prepd. from ND DSB HP strain is completely harmless and does not have an adverse influence onbody mass gain. Large numbers of chickens can be immunised via the drinking water or in a spray.

Serologischer Nachweis von Antikörpern gegen das Newcastle Disease Virus bei Wassergeflügel mittels Hämagglutinationshemmungs‐Test und Enzym‐Immuno‐Assay

Abstract: Summary 8410 samples from Moscovy duck, Pekin duck and geese were incorporated into examinations of antibodies against the Newcastle Disease virus. A new enzyme-immuno-assay (EIA) for antibody detection in Moscovy duck and Pekin duck was developed using purified antigen from NDV-strain “La Sota”. The epidemiology as well as the relation of incidence of the Newcastle Disease in waterfowl was discussed. Zusammenfassung In Untersuchungen zum Nachweis von Antikorpern gegen das Newcastle Disease Virus (NDV) wurden 8410 Serumproben von Moschusenten, Pekingenten und Gansen einbezogen. Zum Antikorper-Nachweis wurde auf der Basis des NDV-Stammes “La Sota” ein neuer Enzym-Immuno-Assay (EIA) fur Moschus- und Pekingenten entwickelt. Epidemiologische Fragestellungen der Newcastle Disease bei Wassergeflugel werden diskutiert.