Advances in Animal and Veterinary Sciences
Virulence of Newcastle Disease Virus and Diagnostic Challenges
Namdeo Rajendra Bulbule, Dhananjay Shesharao Madale, Chandraprakash Dinanath Meshram, Ravi Bhagwan Pardeshi, Milind Madhukar Chawak*
Poultry Diagnostic and Research Center, Division of Venkateshwara Hatcheries Private Limited, Loni-Kalbhor, Pune, India.
*Correspondence | Milind Madhukar Chawak, Poultry Diagnostic and Research Center, Division of Venkateshwara Hatcheries Private Limited, Loni-Kalbhor, Pune, India; Email: chawakmm@rediffmail.com
Abstract
Newcastle disease (ND) is economically most important poultry disease and distributed worldwide causing devastating loses in poultry industry. Newcastle disease virus (NDV) has a wide host range and has been reported to infect more than 240 species of birds. In chickens virulence ranges from non-virulent, associated with asymptomatic enteric infections or unapparent or mild disease of respiratory tract (lentogenic strains), mild respiratory disease and moderate mortality rates (mesogenic strains) to severe disease with high mortality rates up to 100% (velogenic strains). Virulence of NDV strains depend greatly on the host response. Virulence of ND viruses is measured by scoring disease incidence after Intracerebral inoculation of day-old chickens. Highly virulent strains of NDV can be discriminated from low virulent strains by the presence of multibasic amino acid motif at the proteolytic cleavage site of the fusion (F) protein. Genetic classification has divided NDV into 2 classes (I and II), with class I composed of only 1 genotype (class I, genotype I) and with class II divided into 18 genotypes (class II, genotypes I–XVIII). Genotypes V, VI, and VII are virulent viruses and predominant genotypes circulating worldwide. Out of these, genotype VII is particularly important because it is associated with many or the most recent outbreaks in Asia, Africa and Middle East. For rapid and accurate diagnosis real time RT-PCR tests are equally or more sensitive than virus isolation and are always faster than virus isolation. Vaccination against ND is widely practiced. However, ND is still recognised to be endemic in many parts of the world, particularly in developing countries.
Keywords | NDV, Virulence, RRT-PCR
Editor | Muhammad Zubair Shabbir, Assistant Professor, Quality Operations Laboratory, University of Veterinary and Animal Sciences, Lahore, Pakistan.
Received | June 03, 2015; Revised | July 13, 2015; Accepted | July 15, 2015; Published | July 29, 2015
Citation | Bulbule NR, Madale DS, Meshram CD, Pardeshi RB, Chawak MM (2015). Virulence of Newcastle disease virus and diagnostic challenges. Adv. Anim. Vet. Sci. 3(5s): 14-21.
ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331
Copyright © 2015 Bulbule et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
