Localization and Persistence of Toxoplasma in Tissues of Experimentally Infected White Rats.

Abstract

White rats were inoculated intraperit. and the presence of toxoplasma in the tissues was determined by subinoculating the macerated tissues into mice. Parasites appeared in the blood after 4 hours and were present regularly for the next week and sporadically during the next few weeks. Max. concn. was reached between the 4th and 5th days. Parasites were found in small numbers in the liver, spleen and lungs at 4 hours but more regularly after that for 7 days in the liver, 9 days in the spleen, and 11 days in the lungs, and irregularly after these periods of time for 10 weeks in the liver and lungs, and for 2 weeks in the spleen. They appeared in the brain at 4 days and were uniformly present thereafter for a period of 2 years, which was the longest interval of time that the tissue was examined. The organism could be maintained by passage of rat brain to other rats by the peritoneal route.