Use and misuse of trypanocides and comparison of putatively Drug sensitive and resistant strains of trypanosome Congolense isolated from Tanzania

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Date

2020

Journal Title

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Volume Title

Publisher

Sokoine University of Agriculture

Abstract

Background: Tsetse-borne African Animal Trypanosomosis (AAT) greatly influences livestock distribution and significantly slows livestock productivity in sub-Saharan Africa. While a number of control methods targeting the vector tsetse are in field application, treatment with the few available trypanocides continues to be the most widely applied control method. Unfortunately, improper and frequent use of these few available drugs, accelerated by poor veterinary service delivery, promote trypanosome drug resistance, the magnitude of which has not been delineated. In the present study, current practices on trypanocides application for control of bovine trypanosomosis in the field in Tanzania were studied with a view to policy advice on safe and sustainable use of trypanocides. Methods: A cross-sectional study was conducted using a semi-structured questionnaire administered to a total of 200 randomly selected livestock keepers in selected pastoral and agropastoral areas within three districts namely Korogwe, Pangani and Mvomero in eastern and north-eastern Tanzania. The data were handled using excel spreadsheet and later exported to Epi-Info™ software program version 7 for descriptive analysis. Results: In total, 50% of respondents in all three study districts had primary level of education; over 40% had informal education and 5% with university education (all from Pangani district). Most of the respondents aged 30-59 years with exception of Korogwe district where 35% aged 20 -29 years. Over 95% of the respondents had knowledge on tsetse as a vector of trypanosomosis and correctly identified tsetse in provided pictures. Furthermore, 98.7% of the respondents applied pyrethroids for tsetse vector control. Regarding parasite control practices, this study revealed significant variation in the usage and application intervals of trypanocides. Whereas only 20% of the respondents used chemoprophylaxis for trypanosomosis control, 69-95% wrongly used diminazene aceturate thinking it is prophylactic while it is not. About 5-30% of the respondents used the prophylactic drug isometamidium chloride. Most of the respondents (95% in Korogwe, 60% in Pangani and 93.1% in Mvomero) administered the drugs on their own. Improper administration of trypanocides was significantly high in all study districts. The respondents in Korogwe (75%) and Mvomero (72%) administered the drugs intravenously with a view to achieve faster drug effect contrary to manufacturers’ recommendations. The respondents (40%) in Pangani district used both intravenous and intramuscular routes. Additionally, all respondents did not observe the recommended withdrawal periods for the drugs. Conclusion: This study revealed high level of trypanocides misuse that poses a high risk of trypanosome drug resistance development as well as risks to human health from drug residues in consumed animal products. This calls for improvement of veterinary service delivery in pastoral and agropastoral areas of Tanzania to forestall misuse of chemotherapeutics.

Description

PhD Thesis

Keywords

Trypanocides, Insecticides, Trypanosomosis control, Tsetse, Veterinary service delivery, Drug misuse

Citation