Trichinella spiralis: changes in leucocytes during infection.

Rats infected with Trichinella spiralis were examined during the course of infection for various changes in the leucocytic population. In each experiment rats were divided into three groups: Group A, inoculated with Escherichia coli B-5-lipopolysaccharide (LPS) administered four days before each experiment; Group B, infected with Trichinella spiralis; and Group C, untreated controls.An extensive leucocytosis was observed in the peripheral blood and peritoneal cavity of infected rats. Regardless of the site (peripheral blood, bone marrow, peritoneal cavity), the most obvious change was an increase in eosinophils. Differential counts of peritoneal exudate cells also revealed a significant population of macrophages. Acid phosphatase activity, macrophage phagocytosis of polystyrene latex particles, and macrophage spreading revealed that peritoneal exudate cells from T spiralis-infected rats are activated from 6 to 48 days postinfection.This paper serves to reinforce existing information on the changes and state of the various leucocytic populations during infection with T spiralis and aids in assessing the activity change of macrophages.