Can dengue test differentiate between primary and secondary infections?

Yes, the Dengue ELISA test can help differentiate between primary and secondary infections by measuring the levels of IgM and IgG antibodies. In primary dengue infection, IgM antibodies appear first, usually within a few days to a week after symptom onset, and are detectable by ELISA. IgG antibodies appear later and persist for years. In secondary dengue infection, the IgG antibody levels rise rapidly and are detectable early in the infection, often along with or even before IgM antibodies. The relative levels of IgM and IgG can help distinguish between primary and secondary infections, which is important for assessing the risk of severe disease due to antibody-dependent enhancement.