Tsetse-transmitted trypanosomes--their biology, disease impact and control.

Tsetse-transmitted trypanosome infections of man and animals occur across large areas of sub-Saharan Africa and are a major cause of ill-health and death. Although many details of the biology of tsetse-transmitted trypanosomes and the diseases they cause have been clearly established their control has proved extremely difficult. In part this is because trypanosomes show amazing antigenic variation of their surface coat and this has prevented the development of an effective vaccine. Also the few drugs which are available for treatment are unsatisfactory and often have severe side-effects. Significant progress has been made through tsetse control but such programmes are expensive and frequently re-infestation occurs. There is an urgent need for more effective disease diagnostic methods, new safer drugs and more sustained international support for integrated control programmes.