Evaluation under field conditions of the colourimetric DELI-microtest for the assessment of Plasmodium falciparum drug resistance

Trans R Soc Trop Med Hyg. Jan-Feb 2001;95(1):100-3. doi: 10.1016/s0035-9203(01)90351-7.


It has been frequently stressed that improved methods are needed to monitor the fast spread of drug-resistant Plasmodium falciparum parasites in endemic areas. We recently developed a colourimetric microtest, double-site enzyme-linked lactate dehydrogenase enzyme immunodetection assay (DELI), to assess drug resistance in vitro. This method, which proved highly effective under laboratory conditions, was evaluated under field conditions in 2 African areas (in Senegal and Burkina Faso) in 1997 and 1998, respectively. The sensitivities of isolates from symptomatic (n = 50) and asymptomatic individuals (n = 26) infected with P. falciparum were assessed in parallel by the new DELI-microtest and the isotopic-microtest. IC50 values of the isolates determined for chloroquine, quinine, amodiaquine and mefloquine were well correlated (r = 0.79, P < 0.001). The proportions of sensitive and resistant isolates determined using the 2 methods were similar. The DELI-microtest proved to be faster to implement than the isotopic-microtest, easier to perform, and did not require sophisticated equipment. Moreover, a larger number of isolates can be tested since parasitaemias as low as 0.005% could be reliably measured with the DELI-microtest. These initial field studies thus support the value of the DELI-microtest for large-scale drug-sensitivity monitoring.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Colorimetry / methods*
  • Colorimetry / standards
  • Drug Resistance
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Enzyme-Linked Immunosorbent Assay / standards
  • Humans
  • L-Lactate Dehydrogenase / metabolism
  • Malaria, Falciparum / drug therapy*
  • Parasitic Sensitivity Tests / methods
  • Parasitic Sensitivity Tests / standards


  • L-Lactate Dehydrogenase