ISOLATION OF CHICKEN ANEMIA VIRUS FROM BROILER-CHICKENS IN NEW-ZEALAND

Chicken anaemia virus was isolated for the first time in New Zealand f rom the New Zealand domestic chicken population. The virus was recover ed from diseased birds in five separate flocks of broiler chickens age d between 14 and 33 days of age. Six isolates were obtained from bone marrow and lymphoid tissues using the MDCC-MSB1 cell line derived from Marek's disease lymphoma. All isolates were resistant to chloroform a nd survived exposure to 70-degrees-C for 5 minutes. The main clinical features consistently associated with the disease outbreaks were incre ased mortality, yolk sac infections, sub-cutaneous haemorrhages and at rophy of the thymus. Fungal pneumonia occurred in two flocks, and gang renous dermatitis as a result of bacterial infection in another flock. Microscopic examination showed atrophy of the thymus, reduced medulla ry haematopoiesis and inflammation resulting from secondary infections .