1. POSTER TEMPLATE BY: www.PosterPresentations.c om EVALUATION OF A NEW ELISA DIAGNOSTIC KIT FOR CHIKUNGUNYA AND APPLICATION IN AN OUTBREAK SITUATION Caroline Wasonga 1, Shingo Inoue 2, James Kimotho 3, Juliette Ongus 4, Rosemary Sang 3, Lillian Musila 5 University of Nairobi 1, Nagasaki University 2, Kenya Medical Research Institute 3, Jomo Kenyatta University of Agriculture and Technology 4, USAMRU-K 5 Email- cwasonga@uonbi.ac.ke or caroline.otieno@usamru-k.org; KENYA EMERGING ARBOVIRUSES  Chikungunya (CHIK) and Dengue(DENV) fevers are mosquito-borne viral diseases of humans characterized by fever, arthralgia and fatigue.  Increased trade and travel has introduced CHIKV vectors to all continents with an increasing risk for globalization of these viral diseases.  CHIK fever remains a disease of regional public health concern.  In the most recent CHIK outbreak in Kenya in 2004 detection was delayed by lack of accurate diagnostics.  Sero-surveillance was hindered by the limited and expensive available commercial diagnostics.  The objective of this study was to develop a diagnostic assay that can detect acute CHIKV infection in humans. METHODS ACKNOWLEDGEMENT OPTIONAL LOGO HERE EXPECTED OUTPUT 11 OBJECTIVES 1.Produce cell-culture derived viral antigens 2.Produce polyclonal antibody against Chikungunya virus for ELISA assays 3.Validate the new reagents against existing reagents by comparing their sensitivity and specificity 4.Modify the ELISA test based on the new reagents and compare its performance with the existing traditional MAC-ELISA test CONCLUSION  Stock ELISA reagents for diagnosis of human cases of Chikungunya virus that can distinguish it from other arboviruses and for continuous disease surveillance.  Capacity building to develop diagnostic reagents for emerging and endemic arboviruses FRNT (n =148) +-Total New IgM Capture ELISA +51354 -58994 5692148 CDC IgM ELISA (n=154) +-Total New IgM Capture ELISA +422163 -28991 44110154 Table 2 Comparison of the newly developed CHIKV ELISA against CDC ELISA test. Sensitivity was 95.5% and specificity 80.9 %. Table 1 Comparison of the newly developed CHIKV ELISA with the gold standard FRNT. Sensitivity was 91.1% and specificity 96.7 %  Consortium for National Health Research for funding the project.  USAMRU-K, VHF Laboratory and SATREPS for their technical support  KEMRI and Jomo Kenyatta University of Agriculture and Technology for training  Comparison of the in-house IgM ELISA with the FRNT /CDC ELISA demonstrated sensitivity (91.1%, 95.5%) and specificity (96.7%, 80.9%) that were considerably acceptable.  There is a strong correlation between the IgM titer and FRNT titer which shows that the developed diagnostic kit is reliable for diagnosis  The kit was used to detect the circulation of CHIK during the Dengue outbreak that occurred in Kenya in 2013, which would have otherwise gone undetected.  The successful development, evaluation and application of this assay represents a major step in developing the capacity in local Kenyan institutions to develop reagents to diagnose, survey and evaluate the impact of neglected diseases in Kenya Table 3: Identification of CHIK IgM positive cases. (Assay cut off: P/N Ratio of 2.0) DETECTION OF CHIKUGUNYA CASES MASKED BY THE DENGUE OUTBREAK OF 2013 Figure 1: Countries with documented Chikungunya virus activity during the 2004– 2011 outbreak. Year listed is the year activity was first confirmed., including first time cases and previous reports. Assay Validation Assay Development Cell Culture Large-scale Antigen Production Antigen Purification Polyclonal antibodies generated in Rabbit CHIK and DENV occur in the same environment and are transmitted by the same mosquito species, therefore, the newly developed kit was used to screen samples from the recently reported DEN outbreak A panel of human sera was analyzed with the newly developed IgM ELISA assay and the Focus Reduction Neutralization Assay (FRNT) and the IgM CDC ELISA as reference tests. Districts Total samples CHIK cases Male: Female age group (years) Mombasa28519 18:13 - 75 Wajir West242 2:05 -14 Nairobi42 3:15 -6 Wadajir- Somalia 162 1:119 -25 Figure 2: Co-circulation of Chikungunya and Dengue viruses in a recent Dengue outbreak VALIDATION OF THE DEVELOPED CHIK IgM ELISA ASSAY Affordable Diagnostic ELISA Antigen preparation DISCLAIMER The opinions and views in this poster are the private views of the authors; CNHR is not responsible for the direction of the work. The views expressed are not to be considered as official, or as reflecting the views of USAMRU-K or the United States Departments of the Army and Defense.