Preliminary characterisation of isolates of chicken anaemia agent from the United Kingdom.

Two isolates of chicken anaemia agent (CAA) were made from livers obtained from broiler flocks with runting stunting syndrome. Following primary isolation in SPF chicks, both isolates were propagated in MDCC-MSB1 cells. Both were resistant to heat and chloroform-treatment, and were antigenically related to the Cux-1 isolate of CAA by cross-immunofluorescence and cross-neutralisation tests. The isolates produced anaemia and characteristic lesions in 100% of experimentally inoculated 1-day-old susceptible chicks, but anaemia was observed in only 15 to 20% of inoculated 7-day-old chicks.