scholarly journals Role of Pigeons in the Transmission of Avian Avulavirus (Newcastle Disease-Genotype VIId) to Chickens

Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 338 ◽  
Author(s):  
Hany F. Ellakany ◽  
Ahmed R. Elbestawy ◽  
Hatem S. Abd El-Hamid ◽  
Rasha E. Zedan ◽  
Ahmed R. Gado ◽  
...  
Keyword(s):  
Newcastle Disease ◽  
Post Infection ◽  
Broiler Chickens ◽  
Mortality Rates ◽  
Fatal Disease ◽  
Free Range ◽  
Viral Shedding ◽  
Commercial Broiler

Newcastle disease is an acute fatal disease of poultry. The aim of this study was to determine the dynamics of the transmission of avian avulavirus (velogenic viscerotropic Newcastle disease-genotype VIId) from either intramuscularly (IM)- or intranasally (IN) infected 8-week-old Egyptian Baladi pigeons in contact with commercial Arbor Acres broiler chickens (4 weeks of age). The mortality of IM infected chickens and pigeons was 10/10 for chickens and 8/15 for pigeons, while the mortality of IN infected chickens and pigeons was 7/10 for chickens and only 1/15 for pigeons. The concentration of viral shedding in the oropharynx was higher than that in the cloaca for both IN and IM infected pigeons. Pigeons infected IN continued shedding the virus from the oropharynx from the 4th day post-infection (dpi) up to the 16th dpi, while IM infected pigeons stopped oropharyngeal shedding at the 11th dpi. Chickens in contact with infected pigeons developed severe respiratory, digestive and nervous signs. The mortality rates in chickens in contact with IM and IN infected pigeons were 2/5 and 3/5, respectively. Chickens in contact with IM infected pigeons showed higher viral shedding titres in both the oropharynx and cloaca than chickens in contact with pigeons infected IN. In conclusion, free-range pigeons are considered an efficient carrier and transmitter of NDV-VIId compared to commercial broiler chickens raised in open houses.

scholarly journals A Herpesvirus of Turkey-Based Vector Vaccine Reduces Transmission of Newcastle Disease Virus in Commercial Broiler Chickens with Maternally Derived Antibodies

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 614
Author(s):  
Timea Tatár-Kis ◽  
Egil A.J. Fischer ◽  
Christophe Cazaban ◽  
Edit Walkó-Kovács ◽  
Zalan G. Homonnay ◽  
...  
Keyword(s):  
Newcastle Disease ◽  
Broiler Chickens ◽  
Economic Loss ◽  
High Morbidity ◽  
Reproduction Ratio ◽  
Vector Vaccine ◽  
Secondary Infections ◽  
Nasal Swabs ◽  
Commercial Broiler ◽  
And Control

Newcastle Disease is one of the most important infectious poultry diseases worldwide and is associated with high morbidity, mortality, and economic loss. In several countries, vaccination is applied to prevent and control outbreaks; however, information on the ability of vaccines to reduce transmission of ND virus (NDV) is sparse. Here we quantified the transmission of velogenic NDV among 42-day-old broilers. Chickens were either vaccinated with a single dose of a vector vaccine expressing the F protein (rHVT-ND) at day-old in the presence of maternally derived antibodies or kept unvaccinated. Seeders were challenged 8 h before the co-mingling with the corresponding contacts from the same group. Infection was monitored by daily testing of cloacal and oro-nasal swabs with reverse transcription-real-time PCR and by serology. Vaccinated birds were completely protected against clinical disease and virus excretion was significantly reduced compared to the unvaccinated controls that all died during the experiment. The reproduction ratio, which is the average number of secondary infections caused by an infectious bird, was significantly lower in the vaccinated group (0.82 (95% CI 0.38–1.75)) than in the unvaccinated group (3.2 (95% CI 2.06–4.96)). Results of this study demonstrate the potential of rHVT-ND vaccine in prevention and control of ND outbreaks.

scholarly journals Antiviral Effect of Phyllanthus amarus Leaf Extract against Newcastle Disease Virus in Broilers

2019 ◽  
pp. 1-9
Author(s):  
C. O. Faeji ◽  
M. K. Oladunmoye ◽  
I. A. Adebayo ◽  
T. T. Adebolu
Keyword(s):  
Newcastle Disease ◽  
Broiler Chickens ◽  
Leaf Extract ◽  
Clinical Signs ◽  
Antiviral Effect ◽  
Mortality Rates ◽  
Negative Control ◽  
Phyllanthus Amarus ◽  
Prophylactic Administration ◽  
Antibody Titers

Background and Objective: Newcastle disease (ND) is a viral disease of economic importance in poultry industry worldwide. This study was conducted to investigate the antiviral potential of n-hexane leaf extract from Phyllanthus amarus (P. amarus). Methodology: A hundred and twenty day old broiler chickens were purchased and raised for the experiment. At four weeks, the birds were randomly assigned into 12 groups of 10 birds each. Chickens in groups 1, 2, 3, and 4 were vaccinated while those in 5, 6, 7, and 8 were left unvaccinated. Groups 9 and 10 served as the positive controls while 11 and 12 as the negative controls. All groups except the negative control were infected. To study the prophylactic effect of the extract, chickens in groups 1 and 5 received 250 mg/l while those in groups 2 and 6 received 500 mg/l of leaf extract for fourteen days before experimental infection. The chickens in groups 3 and 7 received 250 mg/l while those in groups 4 and 8 received 500 mg/l of leaf extract for fourteen days after infection with ND virus to assess the therapeutic effect of the extract. Clinical signs, bodyweight changes and mortality rates were documented. Antibody titers against the virus were determined and postmortem examination was conducted. Results: Results revealed reduction in mortality rates following administration of the n-hexane extract after the challenge. Prophylactic administration of the extract was more effective in reducing the mortality rates of birds due to the virus infection compared to the therapeutic administration. Similarly, antibody titers decreased in a dosage dependent pattern in the prophylactic group. Conclusion: These findings indicate that the n-hexane leaf extract from P. amarus has significant antiviral potentials against ND virus in broiler chickens and that prophylactic administration at 500 mg/l might be a safer approach in utilization of the leaf extract against Newcastle disease.

scholarly journals Isolation and molecular identification of wild Newcastle disease virus isolated from broiler farms of Diyala Province, Iraq

2020 ◽  
Vol 13 (1) ◽  
pp. 33-39
Author(s):  
Amer Khazaal Alazawy ◽  
Karim Sadun Al Ajeeli
Keyword(s):  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Broiler Chickens ◽  
Mortality Rates ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Field Samples ◽  
Poultry Farms ◽  
Allantoic Cavity

Background and Aim: Newcastle disease virus (NDV) remains a major viral disease of poultry. The morbidity and mortality rates of chickens vaccinated with NDV in broiler farms in Diyala Province were 100% and 80%, respectively, rates due to suspected infection with the highly virulent NDV. The present study aimed to isolate and identify the NDV virus and evaluate its pathogenicity in infected broiler chickens at poultry farms. Materials and Methods: Broiler chickens at two commercial poultry farms were suspected of being infected with virulent NDV due to high mortality rates. Virus isolated from samples of intestinal tissues, lungs, trachea, spleen, kidneys, and air sacs was adapted in the allantoic cavity of embryonated specific-pathogen-free (SPF) chicken eggs. The NDV pathotype was determined based on the mean death time (MDT) in eggs as well as the intracerebral pathogenicity index (ICPI) and intravenous pathogenicity index pathogenicity indexes of the isolated samples. Broilers were experimentally infected by inoculation with fluids collected from the allantoic cavities of 60 broilers aged 35 days. Serological and molecular tests were followed by enzyme-linked immunosorbent assay to determine levels of anti-NDV immunoglobulin G, and isolates were identified using a hyperimmune (HI) test and real-time polymerase chain reaction (RT-PCR). Results: Suspected and isolated NDV field samples propagated in the allantoic cavity of 10-day-old fertile SPF chickens were NDV positive in the rapid hemagglutination test within a few seconds. Pathogenicity indices and MDT showed that the isolated NDV was viscerotropic and velogenic. The virus was identified as NDV by the HI test using specific anti-LaSota HI serum and RT-PCR with specific primers and probes. Propagation of the virus in the allantoic cavity of embryonated hen eggs produced a viral titer of 109.5 EID50/0.1 mL. Conclusion: The virus isolated from broiler chicken farms in Diyala Province, Iraq, was viscerotropic and velogenic according to the pathogenicity indices and RT-PCR. The isolated NDV caused 100% morbidity and 90% mortality in NDV-vaccinated and experimentally infected broiler chickens.

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