The fully automated Sysmex XN-31 hematology analyzer can detect bloodstream form Trypanosoma brucei

For fully automated detection and quantification of Plasmodium parasites, Sysmex developed the XN-31 hemocytometer. This study investigated whether the XN-31 can also detect and quantify bloodstream form trypanosomes (trypomastigotes).

Axenic cultures of Trypanosoma brucei brucei were used to prepare two dilution series of trypomastigotes in the whole blood of a healthy donor, which were subsequently examined by the XN-31 as well as by microscopic examination of thin and thick blood films. Trypomastigote intactness during the procedures was evaluated by microscopy.

The XN-31 hemocytometer detected trypomastigotes with a detection limit of 26 trypomastigotes/μL. Scattergram patterns of Trypanosoma and Plasmodium parasites were clearly distinct, but current interpretation settings do not allow the identification of trypomastigotes yet, and therefore, need future refinement.

Proof of concept was provided for an automated fluorescent flow cytometry method that can detect and quantify Plasmodium spp., as well as Trypanosoma brucei trypomastigotes.