Rapid immunochromatographic test to detect NS1antigen, Ig M and Ig G: An alternative to enzyme linked immunosorbent assay in diagnosis of dengue at primary care level.

Abstract

Background: During the recent outbreak of Dengue, there was an alarming increase in the morbidity and mortality in the southern districts of Tamilnadu. Early diagnosis and differentiation of primary and secondary dengue is essential for treat- ment and control measures. Objective: This study was done to compare rapid immunochromatography (ICT) and ELISA in the early diagnosis of dengue by the simultaneous detection of IgM, IgG and NS1 antigen. Methods: Sera from 120 suspected dengue fever patients were tested for IgM, IgG and NS1 antigen by ICT and ELISA methods. Results: Among the tested 120 samples, 37 (31%) for any one marker, 18 (15%) for NS1antigen, 18(15%) for IgM and 25 (21%) for IgG were positive by ICT. By ELISA 58(48%) for any one marker, 22(18%) for NS1, 42(35%) for IgM, and 48 (40%) for IgG were positive. Conclusion: In view of high degree of agreement (96.7%) between ICT and ELISA for NS1 detection, the rapid ICT may be useful at field level particularly where ELISA is not available for the early diagnosis and effective intervention.