Toxoplasmosis among the Ticuna Indians in the state of Amazonas, Brazil.

Results of a serologic survey for Toxoplasma gondii among 408 Ticuna Indians from five villages in western Brazil are presented and compared with the results of 61 non-Indian inhabitants of the town of Codajas, Amazonas. Indirect hemagglutination antibody titers greater than or equal to 64 were found in 39% of the Ticuna population as compared to 77% of the Codajas population. Prevalence rates of titers greater than or equal to 256 were 20.3% for Ticunas and 39.3% for Codajas. Prevalence rates of titers greater than or equal to 256 in Ticuna villages where dietary habits were most variable were higher and more similar to those of non-Indian populations than were the prevalence rates of this titer range in villages where the animal food source was predominantly fish.