Prevalence of Toxoplasma gondii antibodies in sera of domestic cats from Guarulhos and São Paulo, Brazil.

Antibodies to Toxoplasma gondii were determined in serum samples of 502 domestic cats from Brazil by the modified agglutination test (MAT), using formalin-fixed whole tachyzoites and mercaptoethanol. Antibodies (MAT > or = 1:20) were found in 132 (26.3%) of 502 cats. With respect to origin, antibodies were found in 26.7% of 430 stray cats from São Paulo, 10% of 40 stray cats from Guarulhos, and 40.6% of 32 cats from a cat breeder in São Paulo. Antibody titers were: 1:20 in 10 cats, 1:25 in 40 cats, 1:50 in 73 cats, and > or = 1:500 in 9 cats. Exposure rates of T. gondii in cats from São Paulo, Brazil are similar to that in domestic cats in North America.