Avian Influenza A and Paramyxo Viruses Complicating Respiratory Disease Diagnosis in Poultry

Abstract
Four recently isolated viruses of the myxovirus group, namely 3 influenza-A-like viruses[long dash]strain meleagrium (Turkey/Calif/64), strain AC-3 (Turkey/Calif/AC-3/65), and strain 5142 (Turkey/Calif/5142/66)[long dash]and paramyxovirus strain yuacaipa, which appear to be associated with turkey respiratory diseases and reproductive failures were studied in the field and under experimental conditions. The sudden appearance of strain AC-3 and strain 5142 in turkey flocks within a 40-mile radius, and isolation of strain 5142 from the same pedigree breeding flock from which strain meleagrium was recovered 31 months previously, strongly suggests an antigenic shift. A survey for hemagglutination inhibition (HI) antibodies to these 4 agents showed that the infections are found in turkey flocks throughout the United States. The presence of these agents in turkey flocks was highly correlated with sinusitis and airsacculitis of low morbidity and/or lowered reproductive performance in the presence or absence of Mycoplasma sp. Preliminary results show that superimposing strain meleagrium or strain yucaipa had no apparent effect upon NDV Newcastle disease virus HI titers. However, simultaneous exposure of turkeys to strain meleagrium intratracheally and NDV parenterally completely suppressed or blocked the development of detectable strain meleagrium HI antibodies.