|REHMANI, S - University Of Veterinary And Animal Sciences|
|WAJID, A - University Of Veterinary And Animal Sciences|
|BIBI, T - University Of Veterinary And Animal Sciences|
|NAZIR, BUSHRA - University Of Veterinary And Animal Sciences|
|MUKHTAR, NADIA - University Of Veterinary And Animal Sciences|
|HUSSAIN, ABID - Poultry Disease Diagnostic Lab|
|LONE, NAZIR AHMAD - University Of Veterinary And Animal Sciences|
|YAQUB, TAHIR - University Of Veterinary And Animal Sciences|
Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2015
Publication Date: 2/18/2015
Publication URL: http://handle.nal.usda.gov/10113/60784
Citation: Rehmani, S.F., Wajid, A., Bibi, T., Nazir, B., Mukhtar, N., Hussain, A., Lone, N., Yaqub, T., Afonso, C.L. 2015. Presence of virulent Newcastle disease virus in vaccinated chickens in farms in Pakistan. Journal of Clinical Microbiology. 53(5):1715-1718. doi: 10.1128/JCM.02818-14.
Interpretive Summary: Newcastle disease virus (NDV) of very high virulence are rapidly spreading through Asia and the Middle East causing outbreaks of Newcastle disease characterized by significant illness and mortality in vaccinated poultry. These viruses represent a significant threat to the U.S. Commercial NDV vaccines have been developed for their capacity to prevent disease, however, these vaccines do not prevent replication of challenge viruses in studies using vaccinated specific pathogen free birds. Virus replication could lead to persistence of virulent Newcastle disease virus (vNDV) in vaccinated poultry farms. Our studies provide evidence that high levels of persistence of vNDV can occur in highly vaccinated farms and suggest that vaccination in endemic regions may be insufficient to prevent transmission of highly virulent viruses.
Technical Abstract: The sites where virulent Newcastle disease virus persists in endemic countries are unknown. Evidence presented here shows that the same strain that caused a previous outbreak was present in both apparently healthy and sick vaccinated birds from multiple farms that had high average specific antibody titers against Newcastle disease virus (>4.5 log2).