4. Discussion
Within the last decade it has become abundantly clear that African great apes play a significant role in evolution, emergence, and transmission of a range of infectious diseases important for human populations. Simian immunodeficiency viruses and apicomplexan parasites of the genus Plasmodium are among the best known examples (Liu et al., 2010; Calvignac-Spencer et al., 2012; Liu et al., 2014). Although the wild chimpanzees and other African great apes live in regions endemic for African sleeping sickness, the research on their trypanosome infections has been neglected. This situation is mostly caused by the virtually insurmountable difficulties in obtaining blood samples from free-ranging animals and ethical unacceptability of experimental infections on captive animals.