Evaluation of commercialized IgG detection kits for dengue virus, Zika virus, Japanese encephalitis virus and West Nile virus

Abstract

Objective To compare the cross-reactivity of four commercialized IgG ELISA kits for dengue virus, Zika virus, Japanese encephalitis virus and West Nile virus, and to evaluate the commercialized IgG kits for the flaviviruses by using serum samples from healthy people. Methods Convalescent serum samples from 3 cases each of dengue virus, Zika virus and Japanese encephalitis virus infections were selected to evaluate the cross-reactivity of the commercialized IgG ELISA kits by detecting IgG against the four viruses. The serum samples were collected from healthy people in Jiangmen where imported Zika cases were confirmed before collection, and four flavivirus IgG antibodies were detected. Finally, plaque reduction neutralization test was conducted to verify the positive result of Zika virus IgG antibody detected by ELISA. Results The test results of dengue fever, Zika and Japanese encephalitis in convalescent serum samples showed cross-reactions among dengue virus, Zika virus and Japanese encephalitis virus with the commercialized IgG kits. Among the 78 serum samples from healthy people, the positive rates of dengue, Zika, Japanese encephalitis and West Nile viruses were 0%, 10.25%, 47.43% and 0%, respectively by ELISA. Further test showed that there was no neutralizing antibody in the 8 samples that were positive of IgG against Zika virus. Conclusions Cross reactivity was found in the commercialized flavivirus IgG ELISA kits, false positive results will be detected. It is recommended that ELISA test should be combined with other serological methods for clinical diagnosis and epidemiological investigation. Key words: Flavivirus; ELISA kit; Cross-reactivity; Plaque reduction Neutralization test