Development of an immunochromatographic strip for detection of antibodies against duck Tembusu virus.

Duck Tembusu virus (DTMUV), a novel flavivirus, causes severe disease in ducks. There is an urgent need for a rapid and effective diagnostic method to control the spread of DTMUV. We chose the envelope (E) protein from DTMUV as an antigen and combined it with colloidal gold particles as tracers to specifically detect anti-DTMUV antibodies. Based on the double-antigen sandwich format, an immunochromatographic strip (ICS) for the rapid detection of anti-DTMUV antibodies was developed. The ICS showed a high specificity and no cross-reactivity with other sera. By detecting a serially diluted duck anti-DTMUV serum, the sensitivity of the ICS was 16-fold higher than that of the agar gel double diffusion test. Moreover, the ICS was both stable and reproducible, maintaining the same performance at 4°C for at least 6 months. To evaluate the effectiveness of the ICS, 217 duck serum samples were tested with the ICS and an indirect enzyme-linked immunosorbent assay (iELISA). The consistency ratio of positive and negative results between the two methods was 97.87% and 97.06%, respectively. The agreement between the ICS and the ELISA was 97.24%. The ICS developed in this study offers a specific, sensitive, and rapid method to detect anti-DTMUV antibodies.