The objectives of this study were to assess diagnostic performance of the DMF-ELISA for MR IgM and IgG in outbreak settings, including: 1) rapid confirmation of measles or rubella infection (IgM) in a suspected outbreak setting as part of active surveillance; 2) rapid assessment of MR population immunity (IgG) in a confirmed measles outbreak setting; and 3) comparing performance of DMF-ELISA to ELISA reference tests using outbreak specimens. The gene discussed is CD40LG; the disease is rubella.