Development and Evaluation of an in-House IgM-Capture ELISA for the Detection of Chikungunya and Its Application to a Dengue Outbreak Situation in Kenya in 2013

Abstract

Chikungunya (CHIK) is a mosquito-borne viral disease. In the 2004 CHIK outbreak in Kenya, diagnosis was delayed by lack of accurate diagnostics. The study aimed to develop and evaluate an in-house IgM-capture ELISA (in-house ELISA) for the detection of chikungunya virus (CHIKV) infections. Anti-CHIKV antibodies were raised in rabbits, purified and conjugated to horseradish peroxidase. These anti-CHIKV antibodies and cell-culture derived antigen were used to develop the ELISA. To validate the in-house ELISA, 148 patient sera from the 2005 Comoros CHIK outbreak were compared with CDC IgM-capture ELISA (CDC ELISA) and Focus Reduction Neutralization Test (FRNT) as reference assays. The in-house ELISA had a sensitivity of 97.6 % and specificity of 81.3% when compared to the CDC ELISA and a sensitivity of 91.1 % and specificity of 96.7% when compared to FRNT. The 254 clinically suspected dengue patient samples from Eastern Kenya collected in 2013 were tested for CHIKV IgM using the in-house ELISA. Out of the 254 human samples, 26 (10.2 %) were IgM positive. Out of these 26 samples, 17 samples were further analyzed by FRNT and 14 (82.4%) were positive. The in-house ELISA was able to diagnose CHIKV infection among dengue suspected cases in 2013 outbreak.