The three trypanocides used to control tsetse-transmitted trypanosomiasis i
n domestic animals in Africa have been in use for over 40 years and, not su
rprisingly, resistance of trypanosomes to these drugs has emerged. Because
of the relatively limited market in Africa and the high costs of developing
and licensing new drugs, international pharmaceutical companies have shown
little interest in the development of new trypanocides for use in either a
nimals or humans. Therefore, the current challenge is to achieve optimal us
e of the relatively old existing drugs, and it is in this context that the
problem of drug resistance has to be quantified - as discussed here by Stan
ny Geerts, Peter Holmes. Oumar Diall and Mark Eisler.