Isolation of Toxoplasma from the soil during an outbreak of toxoplasmosis in a rural area in Brazil.

During an outbreak of human toxoplasmosis attempts were made to isolate Toxoplasma from soil near Além Paraíba, Brazil. Five soil samples were collected from the gardens and also from humid shady areas near the houses. After several washings, these soil samples were centrifuged in a glucose solution, and the supernate removed to be centrifuged in water. The sediments obtained from each of the five soil samples were then inoculated orally in groups of mice. Only one soil sample, obtained from a vegetable garden, gave rise to infection in mice. Toxoplasma-like cysts were found in the brains of two mice and also a few mice from all the four subsequent passages. Cyst-positive mice presented antibodies against T. gondii. Two young cats, seronegative by the Sabin-Feldman dye test, subsequently ingested the cyst-positive mouse brain. One cat eliminated Toxoplasma-like oocysts between the 5th and 11th days after the infection and the other cat between the 6th and 16th days. Seroconversion was observed in both cats, 15 days after the inoculation. These results further emphasize sanitary precautions essential to the control of Toxoplasma.