Submitted to: Proceedings of North Central Avian Disease Conference
Publication Type: Proceedings
Publication Acceptance Date: September 20, 2003
Publication Date: September 20, 2003
Citation: Fadly, A.M. 2003. Current and future strategies for control of virus-induced neoplastic diseases of poultry. Proceedings of North Central Avian Disease Conference, September 21-23, 2003, Ohio State University. p. 11. Technical Abstract: Virus-induced neoplastic diseases of poultry, namely Marek's disease (MD), induced by a herpesvirus, and the avian leukoses and reticuloendotheliosis induced by retroviruses can cause significant economic losses from tumor mortality as well as poor performance. Successful control of MD is and has been achieved through use of effective conventional vaccines. For now and the foreseeable future, use of vaccines represents the principal strategy for the prevention and control of MD. However, effective biosecurity measures and genetic resistance are critical adjuncts to vaccination in any successful strategy to control MD. On the other hand, there is no doubt that extensive use of vaccines over the last few decades has contributed to the increase in the tendency of MD virus to evolve to greater virulence. This increase in MD virus virulence is a critical factor that is considered in developing various strategies for control of the disease, as it tends to make earlier vaccines obsolete. Recent advances in MD research, namely revealing sequence of MD virus genome and the development of new molecular approaches to manipulate the MD virus genome are currently being used to identify and characterize function of important viral genes and to develop more effective recombinant vaccines. Currently, there is no commercial vaccine available for control of retrovirus-induced neoplastic disease of poultry, avian leukoses and reticuloendotheliosis albeit the development, during the last two decades, of several experimental vaccines against infection with avian leukosis virus (ALV) and reticuloendotheliosis virus (REV). Eradication of such retroviruses is the most effective means for controlling retrovirus infection in poultry. Because REV-induced disease has primarily been sporadic and self-limiting, eradication programs to control ALV, but not REV are well established and are routinely used by chicken primary breeding companies of layer-type and meat-type stocks.