sleeping sickness resists treatment, how come

[Guest guest]

" The second [neurological] stage of African trypanosomiasis is

particularly difficult to treat; treatment regimens in the second

stage fail in 15-30% of cases. The underlying reasons for this are not

well understood. In children, physical and neurological problems can

occur [grain of salt handy?] even after the trypanosome is eliminated

from the body. Additional difficulties with treatment of sleeping

sickness include drug resistance, limited technical expertise in

endemic countries (which limits diagnosis and treatment), and the

continually changing range of antigenic expression seen in T.

brucei,which makes vaccine development difficult. "

http://www.bc.edu/schools/cas/biology/research/insect/tsetse/