Fig. 1
The DENV and ZIKV patient serum specimens from the Hospital for Tropical Diseases, Bangkok, Thailand, collected during 2017–2020, were used in the present study. The y-axis indicates color intensity quantified as milli-absorbance (mAbs) units using an immunochromatogram reader. Results obtained from the TKK 2nd kit for all four DENV serotypes and ZIKV-positive specimens are shown. The green, blue, orange, purple, and black circles represent the DENV-1, 2, 3, 4, and ZIKV-positive serum specimens, respectively, with the median and interquartile range of color intensity (mAbs) (a). The dotted lines indicate linear regression of the correlation between Ct values and color intensity of the TKK 2nd kit (b). The grid line at 15 mAbs on the y-axis is set as the cut-off value of the TKK 2nd kit. Each of the data points represents the result of a single kit.