National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2012

04. A new sensitive competitive enzyme-linked immunosorbent assay using a monoclonal antibody against nonstructural protein 1 of West Nile Virus NY99


Anti-West Nile virus (WNV) monoclonal antibody SHW-7A11 was newly developed for competitive enzyme-linked immunosorbent assay (c-ELISA). SHW-7A11 reacted with nonstructural protein 1 in western blot analysis. SHW-7A11 was relatively specific for the WNV strain NY99 and reacted to Kunjin and Eg101 strains in indirect ELISA. Two c-ELISAs were developed for sera diluted 10 and 100 times, and named c-ELISA10 and c-ELISA100, respectively. Both c-ELISAs detected antibodies against WNV NY99 and Kunjin strains. Little cross-reactivity was observed for antibodies against Japanese encephalitis virus and Saint Louis encephalitis virus in these assays. Using the cut-off point for the Saint Louis encephalitis virus, WNV-infected domestic fowl were found to be positive at day 21 after infection in both c-ELISAs. By comparison, all infected fowl were found to be positive at day 35 after infection in a virus neutralization test. Our newly developed SHW-7A11-based c-ELISA detected WNV infection with 10-100 times diluted sera. Therefore, this c-ELISA can be used for WNV sero-surveillance of domestic fowl and wild birds.
(Center for Animal Disease Control and Prevention)


Hirota J. et al. (2012) Clin. Vaccine Immunol. 19(2): 277-283