Epidemiology and Control Trypanosomiasis is of immense importance, both as a parasite of humans and live stock, and has effectively prevented the use of large areas of central Africa for cattle ranching. The exception is where resistant or tolerant breeds of native cattle are farmed, which is usually in West Africa. It is a disease which is mainly rural in nature but also very focal with discrete areas of infection coincident with the distribution of the vector. It is estimated that between 55-60 million people are exposed to the risk of infection. The principle methods of control are spraying with DDT, clearance of brush to produce brush-free belts to isolate the area.
Tsetse flies are poor flyers and can only fly short distances.
They are also larviperous and solitary releasing their larvae in burrows underground, usual under the protection of the brush. They are therefore difficult to treat with insecticide. Other methods of control include removing reservoir host from the area and breeding resistant stock animals. It is perhaps a testament to the difficulties in vector control that after over 80 years of tsetse eradication programs there is little observable impact on the distribution of this parasite. In addition to infecting humans trypanosomes infect a number of different mammalian hosts and are transmitted by different vectors.