Comparison of a Dipstick Dot-ELISA with Commercial Assays for Anti-Dengue Virus IgM Antibodies

Abstract
Dengue virus infections have undergone dramatic expansion in range, affecting several tropical and subtropical regions of the world. Dengue virus causes life-threatening complications characterized by dengue hemorrhagic fever and dengue shock syndrome. No standard validated test systems are available for serological diagnosis of dengue virus infection. This creates problems in the diagnosis and proper management of patients. Evaluation of a Defense Research and Development Establishment (DRDE) dengue virus dipstick dot-ELISA test, developed in house, vis-à-vis commercially available immunodiagnostic kits was carried out for detection of IgM antibodies. The DRDE dengue dipstick dot-ELISA was performed on the basis of the dot-ELISA principle. Commercial tests, namely, the Panbio Dengue IgM Capture ELISA system (Panbio, Sinnamon Park, Australia) and Pathozyme Dengue M (Omega Diagnostics, Alva, UK), were performed according to the manufacturers' protocols. Ninety-one serum samples collected from the states of Kerala and Delhi, India during August and November of 2004 were used in the present study. The overall agreement among all three tests was found to be only 72.16% for IgM antibodies. Correlations between the DRDE dipstick dot-ELISA and the Panbio kit, between the DRDE dipstick dot-ELISA and the Pathozyme Dengue M kit, and between the Panbio kit and the Pathozyme Dengue M kit were found to be 96, 93, and 94%, respectively. Although the Panbio kit is widely used in various laboratories in India, the DRDE dipstick dot-ELISA promises to be a useful kit because of its field applicability and comparable sensitivity.