A procedure for isolating and freezing metacyclic Trypanosoma brucei gambiense forms in the field

An adaptation of a modified procedure using anion-exchange centrifugation was evaluated to isolate and freeze in field conditions a high number of bloodstream forms of Trypanosoma brucei gambiense for direct in vitro culture. Pellets of trypanosomes were obtained from 62 patients in Central Africa. The presence of trypanosomes was detected in all 62 eluates. The isolation system was efficient. Preliminary results of in vitro culture of 10 thawed samples of trypanosomes were highly promising because no fungal or bacterial contamination was noticed even after 2 weeks of culture.