Pathogenesis of Marek's disease in chickens with maternal antibody
Lesník, F.; Sobota, V.; Mareta, M.; Moreno, A.R.; Vetiak, O.J.
Archiv für Experimentelle Veterinarmedizin 32(1): 127-134
1978
ISSN/ISBN: 0003-9055 PMID: 208481 Document Number: 129694
Histological lesions were studied in chickens with maternal antibody against MD virus at 14-day intervals after their exposure by contact to strain HPRS-16 of MD virus in the first day of life. Initial lesions occurred in liver, kidney, heart, brain and sciatic nerves 14 days after infection. Relatively, the greatest changes were observed between 56 and 70 days after infection. Lesions consisted of slight to severe infiltrations by immature and mature pleomorphic mononuclear cells. Among these cells myeloid type cells occurred too. Sometimes tumorous lesions with intensive mitosis were observed, mainly in the liver. Intranuclear inclusion bodies were also observed mainly among the proliferating epithelial cells of the proventriculus. 14 days after infection changes in the brain were classified as nonpurulent encephalitis. Gross lesions characteristic of MD occurred most frequently in the gonads, liver and the kidney. In one case, 56 days after infection, herpesvirus-like particles were observed by electron microscopy in the tumorous gonads and liver. They measured about 200 to 260 nm in diameter. Degraded and/or aberrant incompleted virus-like particles occurred the most often and completed (enveloped) ones with electrondense nucleoids were observed occasionally. It is concluded that MD in chickens possessing maternal antibody against the virus took a monophasic course.