Two-color lateral flow assay for multiplex IgG/IgM detection of several febrile illnesses. (A) Assay architecture comprised of sample, conjugate, nitrocellulose, and collection membranes. (B) Assay principles involving: Blue latex, anti-IgG, and Red latex, anti-IgM, detection probes for targeting the sample IgG and IgM, respectively, and the recombinant pathogen molecules on the test line for capturing the IgG/IgM to the respective pathogens.