![]() ![]() Furthermore, the timing and contributions of cell-mediated immune responses appear to decrease disease and transmission potential. Differences in virus virulence alter host gene response patterns have been demonstrated. Gene profiling experiments have led to the discovery of novel host genes modulated immediately after infection. However, new techniques and technologies have also allowed for more in depth analysis of the innate and cell-mediated immunity of poultry to NDV. Immunity is derived from neutralizing antibodies formed against the viral hemagglutinin and fusion glycoproteins, which are responsible for attachment and spread of the virus. Protection against NDV is through the use of vaccines generated with low virulent NDV strains. Virulent NDV are listed pathogens that require immediate notification to the Office of International Epizootics and outbreaks typically result in trade embargos. ![]() Low virulent NDV typically produce subclinical disease with some morbidity, whereas virulent isolates can result in rapid, high mortality of birds. Isolates are characterized by virulence in chickens and the presence of basic amino acids at the fusion protein cleavage site. The virus has been reported to infect most orders of birds and thus has a wide host range. They are pleomorphic in shape and are single-stranded, non-segmented, negative sense RNA viruses. Strains of Newcastle disease virus (NDV) belong to the order Mononegavirales, family Paramyxoviridae, and genus Avulavirus, are contained in one serotype and are also known as avian paramyxovirus serotype-1 (APMV-1). ![]() Newcastle disease (ND) remains a constant threat to poultry producers worldwide, in spite of the availability and global employment of ND vaccinations since the 1950s. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
December 2022
Categories |