Invasive Species Compendium

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Abstract

Prevalence of Toxoplasma gondii antibodies in hunter-killed white-tailed deer (Odocoileus virginianus) in four regions of Minnesota.

Abstract

Sera from 1367 white-tailed deer from 4 geographic regions in Minnesota, USA, collected during 4 hunting seasons (1990-1993) were tested for antibodies to T. gondii using the modified direct agglutination test incorporating mercaptoethanol. Sera from 30% of the deer had antibody titres ≥ 25; 8.6% were positive at a titre of 25, 11% at a titre of 50, and 10% at a titre ≥ 500. There was a significant increase in seropositivity with age. Adult deer were twice as likely to be positive as yearlings; yearlings were 2.5 times as likely to be positive as fawns. There was no difference in prevalence by sex when adjusted for age, nor was there age-sex interaction. Only males showed a slight increase in titre with age. There were no significant differences in prevalence among the regions of northeast pine/aspen forest, southwest tall-grass prairie, southeast mixed-hardwood forest, and aspen/oak suburban park land. There were no statistically significant differences by year of collection. The prevalence of T. gondii antibodies in white-tailed deer remains high and deer hunters and consumers should ensure that venison is well-cooked or frozen prior to consumption.