Field assessment of SD bioline malaria species antigen detection by rapid diagnostic tests in Mali

Abstract

Microscopy, the gold standard for routine malaria diagnosis and rapid diagnosis tests (RDTs) are required before artemisinin-based combination therapies for malaria case management in Sub-Saharan Africa. Several RDTs have been recommended by World Health Organization (WHO) for use in endemic areas. The aim of this study was to assess the performance of SD Bioline malaria Ag P.f. test and SD Bioline Ag P.f./Pan test, two new RDTs for malaria diagnosis, before their introduction to Mali. A total of 736 patients with clinical malaria were recruited from October to December, 2009 in four field sites of Mali. 75 tests were transported and exposed to usual field conditions before use. The tests were performed on capillary blood. Light microscopic examination of blood smear was performed as the reference. The sensitivity and specificity for detection of Plasmodium falciparum were 99.7% (95% CI, 98.7 to 100) and 73.3% (95% CI, 64.0 to 80.6) for the SD Bioline malaria Ag P.f test, respectively; 99.1% (95% CI, 98 to 99.7) and 73.3% (95%CI, 65.0-80.6) for the SD Bioline Malaria Ag P.f/Pan test, respectively. The sensitivity for the detection of P. falciparum at parasitemia < 100 parasites/µl were 91.7 and 87.5% for SD Bioline Malaria P.f test and Malaria Ag P.f/Pan test, respectively. The sensitivity of Malaria Ag P.f/Pan test for the diagnosis of non-falciparum species was 91.7% and the specificity was 97.8%. Both SD Bioline malaria antigen P.f and SD Bioline malaria antigen P.f/Pan remained positive for Plasmodium species 2 weeks after malaria treatment. The transportation in routine field conditions did not alter the performance of the tests. Both SD Bioline malaria P.f test and malaria Ag P.f/Pan test were adequate for the diagnosis of malaria countrywide in Mali. Key words: Plasmodium falciparum, SD bioline malaria test, rapid diagnosis tests (RDTs), Mali.