Browsing by Author "GEBEYEHU, ALKADIR"

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    Anthelmintic utilization practices in Ada’a district and in vitro anthelmintics efficacy study against Haemonchus.contortus and Trichostrongylus.columbriformis in Oromia, Ethiopia
    (2020-06) GEBEYEHU, ALKADIR; Dr. Getachew Terefe, Dr. Bersissa Kumsa
    The present study was conducted to assess anthelmintic (AH) utilization practices in Ada’a District of East Showa zone and evaluate the efficacy of commonly used anthelmintic classes of different brands collected from local markets A structured questionnaire survey was undertaken with 100 respondents farmers owning sheep and/or goats. For the Ah efficacy study, four drugs of different brands (Albendazole (ABZ) for egg hatch test, levamisole (LEV) and ivermectin (IVM) for larval motility test, and tetramisole (TMZ) for adult motility test) were investigated against local isolate of Haemonchus.contortus and Trichostrongylus columbriformis. ABZ and LEV brands originated from China (CN), East Africa (EA) and India (IN), Ivermectin from CN, IN and Uruguay (UG), whereas Tetramisole was from CN and IN. Serial dilutions of the drugs were made to achieve concentrations of 1.0, 0.5, 0.25, 0.125, and 0.0625μg/ml. g/ml. To undertake egg hatch test 100 eggs/well of H. contortus or T. colubriformis were incubated with the drugs at 270C for 48 hours. Larval motility test was done with 50L3 of H. contortus or T. colubriformis mixed with the drug of choice and incubated at 25 0C for 24hrs after which motile and nonmotile worms were counted. Similarly, the adult motility test was done with 15 adult H. contortus/well mixed with the test AH and incubated at 370c for 10 hours. All tests were done in triplicates and the median values were taken. Control wells contained eggs, L3 or adult worms with distilled water. The findings show that: a) the questionnaire survey indicated ivermectin was the most commonly used drug (39 %) followed by albendazole (36 %), tetramisole (17 %) and levamisole (8%), b) in the in vitro assays, all tested anthelmintics brands showed concentrationdependent responses on eggs, larvae and adult parasites; c) in egg hatch test on T.colubriformis eggs, CN and IN brands of albendazole performed >50% egg hatch inhibition at all drug concentrations; d) the EC50 for inhibition of T.colubriformis egg hatching was 2.375μg, 0.087μg and 1.199μg respectively for EA, CN and IN brands. The EC50 against H.contortus eggs was 0.504μg, 0.017μg and 1.886μg respectively for EA, CN and IN brands; e) East Africa brand of levamisole was more effective at reducing H.contortus larval motility than Indian brand (92% and 76% respectively) at 0.5μg while it is better at 0.5μg, 0.25μg and 0.125μg against T. colubriformis (P<0.05). The EC50 for inhibition of motility of T.colubriformis L3 by levamisole was 0.057μg and 4.028μg respectively for EA and IN brands suggesting a much better performance of EA brand over the Indian brand. The EC50 of levamisole against H.contortus L3 XIII was 0.058μg and 0.048μg respectively for EA and IN brands; f) the three brands of ivermectin at all concentrations tested had similar efficacy against motility of H. contortus L3. The linear regression for concentration-response curve indicates that the EC50 for inhibition of motility of T.colubriformis L3 by ivermectin was 0.073μg, 0.178μg and 0.040μg respectively for CN, UG and IN brands suggesting a lower performance of the Uruguay brand compared to the others. Similarly, the EC50 of ivermectin against H.contortus L3 was 0.025μg, 5.040μg and 3.061μg respectively for China, Uruguay India brands; g) in the adult motility test, both China and India brands of tetramisole have performed similarly against H. contortus. However, the EC50 was 0.134μg and 5.576μg respectively for CN and IN brands suggesting a marginal performance of the former and a much lower efficacy of the latter brand. In conclusion, excepting for few cases, ABZ, IVM and TMZ brands from china origin are more effective against eggs, L3 and adults of the parasites concerned. On the other hand, LEV from East Africa Company is proven effective against L3 of both parasites whereas LEV and IVM from Indian origin are effective only against L3 of one species at acceptable concentration. Therefore, while recommending anthelmintics of choice such variations must be taken in to account.