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August 22, 1953


JAMA. 1953;152(17):1634-1635. doi:10.1001/jama.1953.03690170048015

Nicolle and Manceaux described in 1908 an intracellular parasite observed in smears of the spleen and other organs of the North African rodent, the gondi. Splendore in the same year made the same discovery in Brazil. These investigators named the parasite Toxoplasma gondii and regarded it as a protozoon. According to Sabin,1 the cardinal characteristics of the species are (1) typical morphology and staining characteristics of extracellular and intracellular forms in films, fresh tissue, or exudate; (2) pathogenicity for such animals as mice, guinea pigs, rabbits, and chicks; (3) obligate intracellular parasitism; and (4) immunologic relationships with established strains. Proof that Toxoplasma is the cause of certain disease conditions in human beings was first obtained in 1939.

The discovery by Sabin and Feldman2 in 1948 of a new immunologic phenomenon, the so-called cytoplasmmodifying or dye test, became the basis of a widely used quantitative test for the determination