newcastle disease
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2022 ◽  
Vol 19 (2) ◽  
Author(s):  
M. Mostaree ◽  
N. Sultana ◽  
M. I slam

Background Newcastle disease (ND) is a contagious and often deadly viral disease caused by the Newcastle disease virus (NDV), affecting a wide variety of domestic and wild birds. The outbreak of this fatal disease is one of the greatest constraints to the expansion of poultry farms, resulting in significant financial losses. Here we report the clinical and pathological features of a ND case from an outbreak in a commercial broiler farm. Materials and Methods A broiler farm with a population of 850 birds aged 27 days reported the death of 100 chickens within 4 days of the onset of the disease in 2019. For investigation, one dead chicken was brought to the department of pathology, Bangladesh Agricultural University, Mymensingh. The case history was recorded, and an autopsy was performed. Portion of the samples were kept in 10% neutral buffered formalin for histopathological study. Results The morbidity and mortality rates were reported to be 17.65% and 11.47%, respectively. Recorded clinical history were depression, off-feed, huddling, gasping, ruffled feathers, greenish diarrhea, soiled vent and the birds were unvaccinated. On external examination, the birds appeared dehydrated, dyspneic and had nasal exudates, ruffled feathers, and soiled vents. Autopsy exhibited prominent gross lesions in the trachea, lungs, proventriculus, gizzard, intestine, cecal tonsil, liver, spleen and cloacal bursa. Grossly, tracheal hemorrhage, severe congestion in the lungs, pin point hemorrhages on the tip of the proventriculur glands, hemorrhage in the cecal tonsil, button-like ulceration in the intestine and mottled spleen were suggestive of ND. Histopathologically, severe enteritis, necrotic mass in the cecal tonsil and proventriculus, lymphoid depletion in the spleen supported the infection of NDV. The clinicopathological findings of the ND outbreak in broiler farm confirmed that it was velogenic viscerotropic in nature. Conclusion ND in commercial flocks remains a threat to the poultry industry in Bangladesh. Implementation of strict biosecurity, husbandry practice and effective vaccination are required to prevent diseases and improve economic stability.


Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 72
Author(s):  
Gordana Nedeljković ◽  
Hrvoje Mazija ◽  
Željko Cvetić ◽  
Mladen Jergović ◽  
Krešo Bendelja ◽  
...  

Newcastle disease (ND) is a highly contagious avian disease. Global control of ND is mainly based on vaccination of poultry; however, reported outbreaks of ND in vaccinated flocks indicate a constant need to re-evaluate the existing vaccines and a development of the new ones. In this study, 4-week-old male chickens of the layer commercial hybrid were immunized oculonasally with a commercial NDV live La Sota vaccine (LS group), a suspension of lyophilized NDV strain ZG1999HDS (ZG group), or saline (Control (K) group). Antibody response was determined by haemagglutination inhibition (HI) assay. Cell-mediated immunity (CMI) was characterized by immunophenotyping of leukocyte’s and T-lymphocyte’s subpopulations (flow cytometry). Applied NDV strains did not cause any adverse reaction in treated chickens. Both strains induced the significantly higher HI antibody response in comparison to the control group, and overall antibody titer was higher in ZG group than in LS group. CMI, manifested as a higher proliferation of B- and T-helper cells, yielded better results in the ZG groups than in the LS group. Based on the obtained results, we conclude that the strain ZG1999HDS is immunogenic and is a suitable candidate for further research and development of poultry vaccines.


Vaccines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Hesham A. Sultan ◽  
Wael K. Elfeil ◽  
Ahmed A. Nour ◽  
Laila Tantawy ◽  
Elsayed G. Kamel ◽  
...  

Class II genotype VII Newcastle disease viruses (NDV) are predominant in the Middle East and Asia despite intensive vaccination programs using conventional live and inactivated NDV vaccines. In this study, the protective efficacies of three commercial vaccine regimes involving genotype II NDV, recombinant genotype VII NDV-matched, and an autogenous velogenic NDV genotype VII vaccine were evaluated against challenge with velogenic NDV genotype VII (accession number MG029120). Three vaccination regimes were applied as follows: group-1 received inactivated genotype II, group-2 received inactivated recombinant genotype VII NDV-matched, and group-3 received velogenic inactivated autogenous NDV genotype VII vaccines given on day 7; for the live vaccine doses, each group received the same live genotype II vaccine. The birds in all of the groups were challenged with NDV genotype VII, which was applied on day 28. Protection by the three regimes was evaluated after infection based on mortality rate, clinical signs, gross lesions, virus shedding, seroconversion, and microscopic changes. The results showed that these three vaccination regimes partially protected commercial broilers (73%, 86%, 97%, respectively, vs. 8.6% in non-vaccinated challenged and 0% in non-vaccinated non-challenged birds) against mortality at 10 days post-challenge (dpc). Using inactivated vaccines significantly reduced the virus shedding at the level of the number of shedders and the amount of virus that was shed in all vaccinated groups (G1-3) compared to in the non-vaccinated group (G-4). In conclusion, using closely genotype-matched vaccines (NDV-GVII) provided higher protection than using vaccines that were not closely genotype-matched and non-genotype-matched. The vaccine seeds that were closely related to genotype VII.1.1 provided higher protection against challenge against this genotype since it circulates in the Middle East region. Updating vaccine seeds with recent and closely related isolates provides higher protection.


2021 ◽  
Vol 5 ◽  
pp. 76
Author(s):  
Shahn P.R. Bisschop ◽  
Andrew Peters ◽  
Gil Domingue ◽  
Michael C. Pearce ◽  
Jeanette Verwey ◽  
...  

Background This study determined whether the naturally attenuated, thermotolerant Newcastle disease vaccine virus I-2 could acquire virulence after five in vivo passages through SPF chickens. Methods Study design was to international requirements including European Pharmacopoeia, Ph. Eur., v9.0 04/2013:0450, 2013. I-2 Working Seed (WS) was compared with five-times-passaged I-2 WS (5XP WS) in intracerebral pathogenicity index (ICPI), Fo cleavage site sequencing and Safety tests. Results The first passage series used a 50% brain: 50% tracheal tissue challenge homogenate and was unsuccessful as I-2 was not detected after the fourth passage. A second passage series used 10% brain: 90% tracheal tissue homogenates. I-2 was isolated from tracheal tissue in each passage. However harvested titres were below the minimum challenge level (107 EID50) specified for the ICPI and Safety tests, possibly reflecting I-2’s inherently low pathogenicity (interestingly caecal tonsils yielded significant titres). Given this the WS and 5XP WS comparisons proceeded. ICPI values were 0.104 and 0.073 for the WS group and the 5XP WS group respectively confirming that I-2, whether passaged or not, expressed low pathogenicity. F0 amino-acid sequences for both WS and 5XP WS were identified as 112R-K-Q-G-R-↓-L-I-G119 and so compatible with those of avirulent ND viruses. In safety, no abnormal clinical signs were observed in both groups except for two chicks in the 5XP WS group, where one bird was withdrawn due to a vent prolapse, and another bird died with inconclusive necropsy results. Conclusions: These data, the issue of low passage titres with little or no virus isolation from brain tissues and the genomic copy approach suggest a need to amend Ph. Eur. v9.0 04/2013:0450, 2013 for naturally attenuated, low pathogenicity vaccine viruses such as I-2. From an international regulatory perspective, the study provides further definitive data demonstrating that Newcastle disease vaccine virus I-2 is safe for use.


Abstract In this study, the prevalence of Avian orthoavulavirus-1 (AOAV-1) (also commonly known as Newcastle disease virus) was investigated in caged birds kept in bird markets in the Lahore district of Pakistan. A total of 354 swab samples were obtained from 14 different species of clinically healthy birds. The overall virus prevalence was 12.7% in 9 out of the 14 species. Phylogenetic analysis of the complete fusion protein (F) gene showed that 23 isolates from different avian species belonged to sub-genotype VII.2 while three isolates of pigeon origin clustered with sub-genotype XXI.1.2. The VII.2 viruses isolated had a high nucleotide identity to viruses repeatedly isolated from poultry in Pakistan from 2011 to 2018. To date, sub-genotype XXI.1.2 viruses have only been identified in Pakistan. These findings suggest that the Newcastle disease (ND) outbreaks occurring in Pakistan involve multiple hosts and environments. The study emphasises the importance of continuing to monitor multiple avian species for the presence of AOAV-1s and implementing effective ND control strategies.


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