Avian encephalomyelitis virus antibodies in New Zealand chicken flocks

Abstract Extract Madam:— Avian encephalomyelitis (AE) virus is a picornavirus which produces a clinical disease only in young chickens, especially those 2–3 weeks old. Affected birds exhibit ataxia, tremors of the head and neck and there is an average mortality of 10%. (1) Clear epidemiological evidence linked the clinical form of the disease with a series of egg production drops in 1977 in several North Island multi-age laying farms, which were rearing affected batches of chickens. (2) Between 1980 and 1982 Howell tested pooled samples from 40 New Zealand laying chicken flocks (which had not been Ae vaccinated) using the serum neutralization (SN) test. (3) Neutralizing antibody levels indicative of infection with AE virus were detected in 47% of these flocks. (2) Recently on agar gel precipitin (AGP) test was described which appeared to offer a more convenient method for detecting antibodies. (4) We present the results obtained with this test, after assaying a selection of samples routinely submitted to ...