U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Main content area

Pathogenesis of New Strains of Newcastle Disease Virus From Israel and Pakistan

P. Pandarangga, C. C. Brown, P. J. Miller, R. Haddas, S. F. Rehmani, C. L. Afonso, L. Susta
Veterinary pathology v.53 no.4 pp. 792-796
animal pathology, Avian orthoavulavirus 1, nucleoproteins, immunohistochemistry, respiratory system, intestines, genotype, pathogenesis, cerebrum, virulence, tissues, White Leghorn, tissue tropism, mortality, histopathology, virulent strains, chickens, epizootic diseases, laboratory animals, Middle East, Pakistan, Israel
In the past few years, Newcastle disease virus (NDV) strains with epizootic characteristics belonging to subgenotypes VIIi and XIIIb emerged in the Middle East and Asia. In this study, 2 NDV strains—1 representative of subgenotype VIIi isolated in Israel (Kvuzat/13) and 1 representative of subgenotype XIIIb isolated in Pakistan (Karachi/07)—were characterized by intracerebral pathogenicity index and detailed clinicopathologic assessment. The intracerebral pathogenicity index values for Kvuzat/13 and Karachi/07 were 1.89 and 1.85, respectively, classifying these strains as virulent by international standards. In 4-week-old White Leghorn chickens, both strains caused 100% mortality within 4 (Kvuzat/13) and 5 (Karachi/07) days postinfection. Histopathology and immunohistochemistry for NDV nucleoprotein showed that both strains had wide systemic distribution, especially targeting lymphoid organs and mucosa-associated lymphoid tissues in the respiratory and intestinal tracts. Results of the animal experiment confirm that both Kvuzat/13 and Karachi/07 are highly virulent and behaved as velogenic viscerotropic NDV strains.