Trends in diagnosis of Marek´S disease (MD) in poultry at Central Veterinary Laboratory in Dar es Salaam, Tanzania

Abstract

Marek‘s Disease virus (MDV), is a DNA virus a highly contagious herpes virus is considered endemic in the global poultry environment. Retrospective data from January 2012 to December 2016 was analysed to determine the trend of occcurence of Mareks Disease in Dar es Salaam Region. During the period of 5 years 580 chickens were examined and their age category was 10 – 16 weeks of age were 250 birds whereas above 16 weeks of age were 330. Pooled organs namely liver, proventriculus, bursa of Fabricious, thigh muscles and sciatic nerves were sampled and stored in 10% formalin and histopathological sections were prepared and stained with Haematoxyclin and Eosin. Microscopic observation was done at 10x and 40x magnification where by the pleomorphic infiltration of lymphocytes were observed in tissue sections which suggested Marek disease positive. Marek disease was detected in 376 out of 386 (97.4%) chickens of 10-16 weeks old and 100 (51.5%) out of 194 chickens above 16 weeks old showed MD positive. From the above results, it shows that Marek‘s disease in Dar es Salaam is endemic with high prevalence. If not controlled, Marek‘s disease will keep on causing a great economic losses and unhealthy condition to chickens. Hence education on vaccination against the disease should be encouraged to reduce the risk of disease occurance in da es Salaam and other places in Tanzania.

Key words: Control, diagnosis, Marek´s disease,vaccination