THE MIGRATION AND ATTRITION OF STRONGYLOIDES-RATTI IN NAIVE AND SENSITIZED RATS

Compressed organ autoradiography has been utilized to study the migrat ion of the homogonic strain of Strongyloides ratti from the site of sk in penetration to the gut. This transit is characterized by rapid disa ppearance of parasites from the cutaneous site of infection, followed by vascular dispersal throughout all organs investigated. For the firs t time, parasite migration in both naive and previously sensitized hos ts is compared; the principal stations of migration are the same in th e two groups although there is a quantitative difference in accumulati on of parasites with time in these stations. Parasite attrition occurs in both groups of animals; however, in naive rats it is not manifest until day 20-25 post challenge, whereas in sensitized rats immune elim ination occurs as early as 48 h post challenge.