Accordance and concordance of PCR and NASBA followed by oligochromatography for the molecular diagnosis of Trypanosoma brucei and Leishmania.

Objective: To evaluate the repeatability and reproducibility of four simplified molecular assays for the diagnosis of Trypanosoma brucei spp. or Leishmania ssp. in a multicentre ring trial with seven participating laboratories.

Methods: The tests are based on PCR or NASBA amplification of the parasites nucleic acids followed by rapid read-out by oligochromatographic dipstick (PCR-OC and NASBA-OC).

Results: On purified nucleic acid specimens, the repeatability and reproducibility of the tests were Tryp-PRC-OC, 91.7% and 95.5%; Tryp-NASBA-OC, 95.8% and 100%; Leish-PCR-OC, 95.9% and 98.1%; Leish-NASBA-OC, 92.3% and 98.2%. On blood specimens spiked with parasites, the repeatability and reproducibility of the tests were Tryp-PRC-OC, 78.4% and 86.6%; Tryp-NASBA-OC, 81.5% and 89.0%; Leish-PCR-OC, 87.1% and 91.7%; Leish-NASBA-OC, 74.8% and 86.2%.

Conclusion: As repeatability and reproducibility of the tests were satisfactory, further phase II and III evaluations in clinical and population specimens from disease endemic countries are justified.