Sensitivity of isolates of Trichinella to the drug thiabendazole

• Published in: Canadian Journal of Zoology
• Main Authors: Chadee, K., Dick, T. A., Faubert, G. M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1983
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Arctic; polar bear; wolverine
• Online Access: http://dx.doi.org/10.1139/z83-017; http://www.nrcresearchpress.com/doi/pdf/10.1139/z83-017

The sensitivity of three isolates of Trichinella spiralis (from pig, polar bear, and wolverine) and T. spiralis var. pseudospiralis to the anthelmintic thiabendazole (TBZ) was studied in male CD-1 mice. In vitro larval release by female worms isolated on day 7 following drug treatment (2–7 days) with various drug dosages (0.01–0.06%) showed that TBZ treatment resulted in sterility or a decrease in fecundity of the worms. Females of the pig isolate and T. spiralis var. pseudospiralis were chemosterilized with 0.05% TBZ and at 0.03% so were the two Arctic isolates (polar bear and wolverine), but chemosterilization was not permanent. Drug treatment during the disseminating phase (4–20 days) with low dosages (0.03–0.1%) was highly effective in reducing the number of muscle larvae at 40 days postinfection, a reduction that was similar for all Trichinella. Drug treatments (0.03–0.5%) during the early muscle phase (20–40 days) were ineffective with low dosages (<0.15%), but with a higher dosage (0.5%) 99 and 100% efficacy were noted for the two Arctic isolates and T. spiralis var. pseudospiralis, respectively. Larvae recovered at high dosages (>0.15%), were not infective to mice. Treatments with dosages of 0.03–0.1% from 40 to 60 days postinfection were only effective against the Arctic isolates. Of all the Trichinella studied, the pig isolate was the least sensitive to parenteral treatment.