Evaluation of the Sensitivity and Specificity of Rapid Human Immunodeficiency Virus (HIV)1 and 2 Test Kits Commonly Used in Nigeria

Abstract

The sensitivity and specificity of five rapid HIV antibody test kits commonly used in Nigeria were evaluated. The kits were selected based on their high percentage frequency of use as compared to others. A total of 100 EIA HIV-1and RNA HIV-1 positive sera were used as positive gold standard, while 100 EIA HIV-1 and RNA HIV-1 negative sera were used as negative gold standard. The positive gold standard sera were pooled, serially diluted and analysed to determine the sensitivities of the kits. The methods used were strictly as provided by the manufacturers. Of the 100 positive gold standard serum samples used, Immunocomb-II gave false negative results with 10 (Sensitivity = 90%), while HIV-SAV, Hexagon, Determine and SD-Bioline were false negative with 12 specimens, representing 88% sensitivity for each. On the other hand, of the 100 negative gold standard sera, Immunocomb-II gave 6 false positive results (Specificity = 94%), HIV-SAV 12 (Specificity = 88%), Hexagon 2 (Specificity = 98%), Determine 12 (Specificity = 88%), while SD-Bioline had no false positive result (specificity = 100%). In analytical sensitivity, Immunocomb-II detected the highest serum titre of 30 000, making it the most sensitive. Two of the five test kits (Immunocomb and SD-Bioline) demonstrated excellent analytical sensitivity and specificity respectively. The two could be recommended for use as combination test algorithms instead of EIA/Western Blot algorithm, which is time-consuming, expensive and often not technically feasible in a developing country like ours. This study shows that not all the analytical performance indices cited in the literature from the manufacturers of diagnostic kits are necessarily reproducible in end-user laboratories.

Key words: sensitivity, specificity, HIV rapid test kits

Journal of Medical Laboratory Science Vol.13(1) 2004: 11 - 16