Encephalitozoon sp. in the blue-masked lovebird, Agapornis personata (Reichenow): first confirmed report of microsporidan infection in birds.

A microsporidan tentatively classified as Encephalitozoon sp. on the basis of structure and tinctorial qualities was identified in tissues from a group of blue-masked lovebirds. Agapornis personata (Reichenow). The organism was present in renal tubular epithelial cells, hepatocytes, bile duct epithelial cells, and intestinal epithelial cells. Focal hepatic necrosis occurred around clusters of the organisms but inflammation was minimal or absent in the other infected tissues. Attempts to infect laboratory mice with the organism were unsuccessful. Ultrastructural features were compared with those of E. cuniculi of mammals.