SEROLOGIC SURVEY FOR TOXOPLASMA-GONDII IN GRIZZLY BEARS FROM ALASKA

Blood samples were collected from 892 grizzly bears (Ursus arctos) in Alaska (USA) from 1973 to 1987. Sera were tested for evidence of expos ure to Toxoplasma gondii by means of the modified agglutination test. Two hundred twenty sera (25%) had titers less than or equal to 25, the minimum threshold titer. Six hundred seventy-two sera (75%) had titer s <25. Antibody prevalence ranged from 9% (18 positive of 196 tested) in southern areas to 37% (162 of 433 tested) in northern areas. There was no readily apparent explanation for these discrepancies in locatio n-specific prevalence.