Identification of the chicken anemia agent, reproduction of the disease, and serological survey in the United States.

An agent with antigenic, physicochemical, and pathological characteristics of chicken anemia agent (CAA) was isolated from broiler chickens and was designated chicken infectious anemia (CIA)-1. CIA-1 was resistant to chloroform treatment and passed through 50-nm-diameter-pore membranes. When inoculated in embryonally bursectomized and/or intact chickens, CIA-1 produced signs and lesions characteristic of CIA: low hematocrit values, pale bone marrow, thymic and bursal atrophy, and enlarged liver. Microscopic lesions were a reflection of macroscopic observations. When injected into 4-week-old chickens CIA-1 induced antibodies against the Cux-1 CAA isolate. In CsCl, CIA-1 had a density of 1.36 g/ml. Antibodies against CAA were found in breeder and commercial chicken flocks from Arkansas, Connecticut, Georgia, Kansas, Maine, Michigan, New York, and Pennsylvania. The age of these flocks ranged from 10 to 78 weeks.