Investigation of the efficacy of two rapid assessment techniques (Optimal 1 and SD-Bioline) for the diagnosis of malaria in rural areas of Nigeria

Abstract

We had previously studied the efficacy of three new techniques-Para Sight F, (PSF), Immunochromatographic Test (ICT) and Quantitative Buffy Coat (QBC) – as possible replacements for the time-consuming microscopy in the diagnosis of malaria. Two more rapid assessment techniques (the Optimal 1 and SD-BIOLINE) were recently introduced into Nigeria and claimed to exhibit high sensitivity and specificity. Optimal 1 was particularly claimed to distinguish between P falciparum, P. malariae, P ovale and P. vivax. We have in this work evaluated the efficacy of both the Optimal 1 and SD-Bioline in 240 patients from Ibafo and Magboro Communities in Obafemi-Owode LGA of Ogun State, Nigeria. Results showed that with regard to the detection of P. falciparum, Optimal 1 gave a sensitivity, specificity, positive and negative predictive values of 63.95%, 92.20%, 82.1% and 82.1% respectively, while the SD-Bioline gave 54.84%, 42.9%, 68.0% and 68.0% respectively. In retrospect, the sensitivities shown by 3 other techniques (ICT, PSF and QBC) investigated by us were 88.63, 89.95 and 87.6% respectively. Their specificities on the other hand were 94.60, 91.17, 94.70% respectively. The main advantage of the rapid Optimal 1 technique is that it was able to detect P. malariae which microscopy also detected in three patients. The SD-BIOLINE gave the worst comparative result and could not be recommended for use in Nigeria. This work in conclusion has shown that Optimal 1 could be useful in the rapid diagnosis of the various species of Plasmodium in Nigeria provided the patients could afford the test. (Af. J. of Clinical and Experimental Microbiology: 2003 4(1): 6-13)