Modelling Marek's Disease Virus (MDV) infection: parameter estimates for mortality rate and infectiousness
Open Access
- 1 January 2011
- journal article
- Published by Springer Science and Business Media LLC in BMC Veterinary Research
- Vol. 7 (1), 70
- https://doi.org/10.1186/1746-6148-7-70
Abstract
Marek's disease virus (MDV) is an economically important oncogenic herpesvirus of poultry. Since the 1960s, increasingly virulent strains have caused continued poultry industry production losses worldwide. To understand the mechanisms of this virulence evolution and to evaluate the epidemiological consequences of putative control strategies, it is imperative to understand how virulence is defined and how this correlates with host mortality and infectiousness during MDV infection. We present a mathematical approach to quantify key epidemiological parameters. Host lifespan, virus latent periods and host viral shedding rates were estimated for unvaccinated and vaccinated birds, infected with one of three MDV strains. The strains had previously been pathotyped to assign virulence scores according to pathogenicity of strains in hosts. Our analyses show that strains of higher virulence have a higher viral shedding rate, and more rapidly kill hosts. Vaccination enhances host life expectancy but does not significantly reduce the shedding rate of the virus. While the primary latent period of the virus does not vary with challenge strain nor vaccine treatment of host, the time until the maximum viral shedding rate is increased with vaccination. Our approach provides the tools necessary for a formal analysis of the evolution of virulence in MDV, and potentially simpler and cheaper approaches to comparing the virulence of MDV strains.Keywords
This publication has 32 references indexed in Scilit:
- Kinetics of Marek's disease virus (MDV) infection in broiler chickens 1: effect of varying vaccination to challenge interval on vaccinal protection and load of MDV and herpesvirus of turkey in the spleen and feather dander over timeAvian Pathology, 2008
- Effects of vaccine dose, virus challenge dose and interval from vaccination to challenge on protection of broiler chickens against Marek's disease virus challengeAustralian Veterinary Journal, 2007
- Vaccinal control of Marek's disease: Current challenges, and future strategies to maximize protectionVeterinary Immunology and Immunopathology, 2006
- Replication kinetics of Marek's disease vaccine virus in feathers and lymphoid tissues using PCR and virus isolationJournal of General Virology, 2005
- Influence of vaccine deposition site on post-vaccinal viraemia and vaccine efficacy in broiler chickens following in ovo vaccination against Marek's diseaseAvian Pathology, 2001
- The changing landscape of Marek's diseaseAvian Pathology, 1998
- Increased Virulence of Marek's Disease Virus Field IsolatesAvian Diseases, 1997
- Marek's Disease—A Model for Herpesvirus OncologyCRC Critical Reviews in Microbiology, 1985
- Selection of Intermediate Rates of Increase in Parasite-Host SystemsThe American Naturalist, 1981
- Immunization against Marek's Disease using a Live Attenuated VirusNature, 1969