HomePhilippine Journal of Veterinary Medicinevol. 55 no. 1 (2018)

Genetic Characterization Of Newcastle Disease Virus From Broiler Flocks In Selected Areas In Central Luzon, Philippines

Rizi Marie C. Beguas, Dvm | Dennis V. Umali, Dvm, Phd

 

Abstract:

Newcastle Disease (ND) is a serious and highly contagious disease of poultry. To infer on the molecular epidemiological characteristics of ND virus involved in recent ND outbreaks in the Philippines, five clinical cases of ND in broiler flocks in Central Luzon were analyzed. Records of management and farm history were obtained to characterize the clinical profile of the disease. All affected broilers were vaccinated against ND using different brands of commercial vaccines at different schedules. Affected flocks showed varying clinical signs and mortality rates. Nucleotide sequencing and phylogenetic analysis were performed using the fusion (F) gene. All field ND virus strains (NDVs) were velogenic with a proteolytic cleavage site of 112RRQKR*F117. Phylogenetic analysis of the five field NDVs showed that all strains belong to subgenotype VIIi and were 99% similar with the novel subgroup of virulent NDVs currently emerging from Indonesia, Pakistan and Israel. All strains were epidemiologically related, and successful elucidation of the progenitor virus may aid in the prevention and control of ND outbreak in broilers.