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

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene Vol. 95; no. 1; pp. 100 - 103
• Main Authors: Moreno, A., Brasseur, P., Cuzin-Ouattara, N., Blanc, C., Druilhe, P.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2001; Royal Society of Tropical Medicine and Hygiene; Elsevier
• Subjects: Animals; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antifungal agents; antimalarial drugs; Biological and medical sciences; Burkina Faso; Colorimetry - methods; Colorimetry - standards; DELI; Drug Resistance; drug-sensitivity assay; ELISA; Enzyme-Linked Immunosorbent Assay - methods; Enzyme-Linked Immunosorbent Assay - standards; Humans; L-Lactate Dehydrogenase - metabolism; lactate dehydrogenase; Malaria, Falciparum - drug therapy; Medical sciences; Parasitic Sensitivity Tests - methods; Parasitic Sensitivity Tests - standards; Pharmacology. Drug treatments; Plasmodium falciparum; Senegal; Tropical medicine; Senegal; Burkina Faso; Africa; Plasmodium falciparum; DELI; antimalarial drugs; Burkina Faso; drug-sensitivity assay; Senegal; lactate dehydrogenase; drug resistance; ELISA; Protozoa; Antimalarial; Evaluation; Apicomplexa; Drug susceptibility test; Colorimetry; Enzyme immunoassay; Clinical isolate
• ISSN: 0035-9203; 1878-3503
• 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.