Explore all the information onMarek´s disease
Marek's disease is a highly contagious viral disease of poultry characterized by T-cell lymphomas and peripheral nerve enlargement. Standard criteria used for diagnosis include history, clinical signs, gross necropsy, and histopathology. Although no treatment is available, current vaccines are highly protective. Chickens are the most important natural host for Marek's disease virus (MDV), a highly cell-associated but readily transmitted alphaherpesvirus with lymphotropic properties of gammaherpesviruses. Quail can be naturally infected, and turkeys can be infected experimentally. However, severe clinical outbreaks of Marek's disease in commercial turkey flocks, with mortality from tumors reaching 40%–80% between 8 and 17 weeks of age, were reported in France, Israel, and Germany. In some of these cases, the affected turkey flocks were raised in proximity to broilers. Turkeys are also commonly infected with turkey herpesvirus (HVT), an avirulent strain related to Marek's disease virus that is commonly used as a Marek's disease vaccine in chickens.
New tests and vaccines are making it easier to detect viruses in chickens and protect them from the cancer-like diseases some of them cause. One of the latest tools developed by scientists at the Agricultural Research Service’s Avian Disease and Oncology Laboratory (ADOL) in East Lansing, Michigan, is a modified polymerase chain reaction (PCR) test to detect unique genetic sequences of both Marek’s disease and avian reticuloendotheliosis...
Dr. Karel A. Schat, Professor of Avian Virology and Immunology at Cornell University, speaks about Marek´s disease, vaccination and vaccine failure during the XX Latin American Poultry Congress in Buenos Aires, Argentina. ...
1 Centre for Infectious Diseases, University Of Edinburgh, West Mains Road, EH9 3JT, UK 2 Center for Infectious Disease Dynamics, Departments of Biology and Entomology, 208 Mueller Laboratory, The Pennsylvania State University, University Park, PA 16802, USA 3 Centre for Animal Health and Welfare, School of Environmental and Rural Science, The University of New England, Armidale NSW 2351, Australia ...
Summary Marek´s disease, even if it is an infectious disease noted for a long time, continues to be loss/making in the farms of broiler chickens, although there are vaccines, which are administrated in the first day of life. The researches from this article aim to study the epidemiological characteristics, clinical findings and necropsy findings in Marek´s disease,...
Marek’s disease (MD) remains a topic of concern, although the current situation indicates an absence of MD problems in most countries. If outbreaks occur it is important that a correct diagnosis is made. Immunohistochemistry using antibodies to the MD oncoprotein meq, avian leukosis virus and reticuloendotheliosis virus-specific proteins may be required in problem cases. ...
National Veterinary Research Institute (Poland)
Summary. The presented study was done on 29 MDV strains isolated from field cases of Marek´s disease in Poland. Molecular analysis performed on these strains by PCR and sequencing of meq oncogene has shown 68 bp insertion. This genetic change resulted in frame shift within 10 recently isolated field strains. These strains were tested by PCR for the detection of long-terminal repeat (LTR) region of reticuloendotheliosis virus (REV). The...
Introduction Marek´s Disease (MD), a lymph proliferative disorder in domestic poultry that exists in virtually all commercial poultry operations throughout the world, is characterized by mononuclear cellular infiltrates in peripheral nerves and several other organs and tissues (Calnek & Witter, 2000; Schat & Nair, 2008; Witter & Schat, 2003). MD has been...
National Veterinary Research Institute (Poland)
Gregorz Wozniakowski, from the National Veterinary Research Institute, Pulawy, Poland speaks about Marek´s disease during the XVII World Veterinary Poultry Association Congress in Cancún, Mexico....
MAREK’S DISEASE MD is a common and important neoplastic disease of chickens caused by serotype 1 herpes virus (MDV). These are related antigenically to non-oncogenic herpes virus of chickens (serotype 2) and turkeys (serotype 3), also known as turkey herpes virus (HVT). Within serotype 1, MDV four pathotypes are recognized: (mild (m), virulent (v), very virulent (vv) and recently, very virulent + (vv+). All pathotypes of serotype 1 cause disease but serotype 1 isolates can be...
An advanced intercross ( F6 ) between two commercial layer lines was used to map genes associated with survival to Marek’s disease using candidate gene and quantitative trait locus mapping approaches. After further validation and fine-mapping, the identified genes and genomic regions can be used to select for increased resistance to Marek’s disease using marker-assisted selection approaches. Introduction Marek’s...
A Poultry CRC-funded epidemiological survey of Australian broiler flocks has indicated that one of the protective factors against Marek's Disease virus may be the use of wood-based litter 1 . A survey of farms across the Australian broiler industry was conducted to establish the prevalence of serotype 1 Marek’s Disease virus (MDV1) in dust collected from the sheds at the end of the batch and to identify risk factors...
Dear professional colleagues,
Mareks disease is a pain in the neck in the poultry industry.I convinced a rapid kit manufacture to make a kit for me which I found useful.i am concerned Because some literature support that mareks disease is only diagnosed if it results in neoplasm, while some literature believe in sub clinical mareks disease which only results in consistent mortality and immunosuppresion without neoplasm .Also the neoplasm school of thought feels mareks virus is ubiquitous and...
Mutations in meq are associated with Marek disease viruses of high virulence.
"Marek disease (MD) is a highly contagious lymphoproliferative and demyelinating disorder of chickens. MD is caused by Marek's disease virus (MDV), a cell-associated, acute-transforming alpha-herpesvirus. For three decades, losses to the poultry industry due to MD have been greatly limited through the use of live vaccines. MDV vaccine strains are comprised of antigenically related, apathogenic MDVs originally...