Evaluation of the OptiMAL Test for Rapid Diagnosis of Malaria

Abstract

This study evaluated the ability of a newly developed rapid test for laboratory diagnosis of malaria. OptiMAL is a rapid test that utilizes a dipstick coated with monoclonal antibodies against the intracellular parasite dehydrogenase (PLDH). The differentiation of Plasmodium species is based on antigenic differences between the PLDH forms. Blood samples from 62 of clinically diagnosed patients were examined using the microscopy of Giemsa-stained blood films and the OptiMAL test. The blood films indicated that 27% of the patients were positive for P.falciparum (including one case of mixed infection with P. malariae), while the OptiMAL test recorded 34% for P. falciparum. The OptiMAL test failed to diagnose malaria at concentrations less than 100 per microliter of blood, while those missed by microscopy may be due to sequestration of the parasite coupled with low parasite density. The OptiMAL test was modified by using fingerprick instead of venepuncture and this simplifies the test both in terms of cost and trained personnel. There was no significant difference between the two methods (x2 = 1.513;P>0.05), but the OptiMAL test has the advantages of being faster, requires almost no specialized laboratory experience and extremely sensitive and specific even in field situations. We conclude that the OptiMAL test is an effective tool for the rapid diagnosis of malaria.


(Af. J. of Clinical and Experimental Microbiology: 2003 4(1): 14-17)