An analysis of trypanocidal drug use in the Eastern Province of Zambia.

As part of the development of a strategy for the control of bovine trypanosomosis in Zambia, a survey was conducted to quantify and qualify the current use of trypanocidal drugs (diminazene aceturate and isometamidium chloride) in a tsetse-controlled and a tsetse-infested area of the Eastern Province. A total of 207 trypanocide users were interviewed. Questions were posed on herd structure, trypanocidal drug preference, treatment strategy, reason for treatment, method of treatment and treatment frequency. The majority of the cattle owners preferred to use diminazene aceturate rather than isometamidium chloride. Both trypanocides were mainly used to treat clinically sick animals (not necessarily infected with trypanosomes) and preference was given to the treatment of oxen and cows. The proportion of animals treated and the frequency of drug application did not differ between the two areas. Hence, in the tsetse-controlled area, a high proportion of the trypanocide treatments was inappropriate. In the tsetse-infested area, on the other hand, the treatment of clinically sick animals significantly reduced the trypanosomosis-related mortality but was insufficient to boost reproduction in cows. Despite the fact that the cattle owners administered most trypanocides themselves, evidence from the survey suggests that most of the farmers did not under-dose with either diminazene aceturate or isometamidium chloride. Moreover, other factors enhancing the development of resistance to trypanocides in trypanosomes were not present in the areas surveyed. Conclusions are drawn on the usefulness of this type of survey in determining appropriate methods to control bovine trypanosomosis.