EFFECT OF VARIOUS DOSES OF INFECTIVE TOXOCARA-CANIS AND TOXOCARA-CATIEGGS ON THE HUMORAL RESPONSE AND DISTRIBUTION OF LARVAE IN MICE

The effect of 5-2,500 infective Toxocara canis and 5-1,000 T. cati egg s on the humoral immune response and on the distribution of larvae in the organism was studied in paratenic hosts - inbred C57BL6/J mice. Wi th each dose of T. canis eggs the maximal antibody level was recorded on day 56 post infection and was followed by a moderate decline that l asted until day 154 of the experiment. A correlation between the antib ody level and the egg count was observed only with the infective dose of 5-50 eggs. A more rapid occurrence of antibodies was recorded in mi ce infected with a high dose of eggs. In those given 5 and 7 T. cati e ggs the antibody level exceeded the extinction threshold value only fr om day 21 to day 84. Low doses of T. canis (n=5) and T. cati (n=7) egg s caused a comparable distribution of larvae in mice, and the larval r ecoveries on day 70 post infection ranged between 10.00% and 25.74%. F ollowing a dose of 500 T. cati eggs, 22.28% of the larvae were recover ed, although only 1.08% were localized in the brain. A dose of 1,000 T . canis eggs yielded 36.37% of the larvae, with as much as 28.13% bein g found in the brain.