Presence and Survival of Marek's Disease Agent in Dust

Abstract

Acute Marek's disease (MD) is a highly contagious disease of the young chicken. The etiological agent is easily transmitted from infected to susceptible chickens by direct or indirect contact (1). It has been demonstrated in oral washings (4,5), air (7), and feces (8) of infected chickens and their environment. Witter et al. (9) suggested that the MD agent may survive for a substantial period outside the host body, a suggestion supported by the presence of the MD agent after complete depopulation. Those workers demonstrated MD agent in litter and droppings from infected chickens. Eidson et al. (3) demonstrated MD agent in adults and larvae of Alphitobius diaperinus recovered from litter contaminated by chickens with MD. It is probable that other sources, not yet identified, may exist in the environment. This paper reports a study of the persistence of MD virus in big broiler houses where the MD agent VUB-X (Veterinary University Brno) was isolated (Jurajda, unpublished data). The infectivity of dust collected from the ventilation system was examined.