Comparison of diagnostic techniques during subclinical single infections of trypanosomiasis in goats

Parasitological diagnostic techniques were compared in caprine hosts in which single subclinical infection with Trypanosoma vivax, Trypanosoma congolense or Trypanosoma brucei brucei had been established. The haematocrit centrifuge technique (HCT) was the most sensitive for the diagnosis of T. vivax and T. b. brucei while the buffy coat method (BCM) proved superior to all other techniques for T. congolense. Except with the miniature anion-exchange/centrifugation technique (mAEC), each of the concentration methods proved as sensitive as a combination of the Standard Trypanosome Detection Methods (STDM) and could detect trypanosomes at concentrations which were five times lower than those required by the STDM. The HCT diagnosed 60.8-90%, with a mean of 78.8%. Corresponding figures for other methods were: wet film, 33.3-50.8 (39.8); mouse inoculation, 0.0-82.5 (47.8); thin film, 43.3-73.3 (52.6); mAEC, 42.4-60.0 (53.2); thick film, 52.9-60.0 (56.2); silicone centrifugation 60.8-77.7 (67.3), and BCM, 60.0-78.4 (71.6). A combination of the HCT and BCM is suggested for routine diagnosis of caprine trypanosome infections.