Leucocytozoon Caulleryi

Synonyms: Leucocytozoon andrewsi Atchley, 1951; Leucocytozoon schueffneri Prowazek, 1912 pro parte.

Hosts: Chicken.

Location: The gametocytes are in the leucocytes and erythrocytes.

Geographic Distribution: Indochina, Malaya, India, Sumatra, North America (South Carolina).

Prevalence: This species is relatively uncommon except perhaps in Malaya. Atchley (1951) found it in 15% of 400 adult domestic chickens in South Carolina, but his is the only report of it in North America. It has been found in Indochina by Mathis and Leger (1909), in Sumatra by Prowazek (1912), in Malaya by Kuppusamy (1936), and in India by Ramanujachari and Alwar (1953), Ramaswami (1955), and Biswal and Naik (1958). In addition, Hamerton (1929) reported a Leucocytozoon without describing it from a domestic chicken and a jungle fowl (Gallus lafayettei) in the London zoo.

Morphology: The mature gametocytes are round, measuring 15.5 by 15.0 u according to Mathis and Leger (1909). According to Atchley (1951) the macrogametes are 12 to 14 u in diameter with a nucleus generally 3 to 4 u in diameter, and the microgametocytes are 10 to 12 u in diameter with a nucleus 10 to 12 u in diameter occupying most of the cell. The host cell is round, about 20 u in diameter according to Mathis and Leger and 13 to 17 u in diameter according to Atchley. The host cell nucleus forms a narrow, dark band extending about a third of the way around the parasite. The macrogametes stain more darkly with Romanowsky stains than the microgametocytes.

Life Cycle: Unknown. Atchley (1951) described exflagellation of the microgametocytes, and figured one with what appeared to be 6 microgametes.

Pathogenesis: This species is presumably pathogenic, but accounts of it have been so mixed up with those of L. sabrazesi (see below) that its pathogenicity is uncertain.

Remarks: Another species of Leucocytozoon, L. sabrazesi, with elongate gametocytes, has been described from the chicken. There has been a good deal of uncertainty as to whether L. caulleryi may not be merely an immature stage of L. sabrazesi. Many of the infections which have been seen have been mixed ones. However, Mathis and Leger, who first described both species, found pure infections of each, and Atchley found only round forms in the 61 infected chickens which he studied, some of which he kept under observation for a year. In addition, Atchley’s observation of exflagellation leaves no doubt that the round forms are mature.