Maeki et al.
Analysis of cross-reactivity between flaviviruses with sera of patients with Japanese encephalitis showed the importance of neutralization tests for diagnosis of Japanese encephalitis
J. Infect. Chemother. 2019, 25: 786-790
Japanese encephalitis (JE) is the most important viral encephalitis in Asia and is usually diagnosed by serological assays. Antibodies between flaviviruses have been reported to show cross-reactivity, and this is in particular true for ELISAs (see Snapshots of week 12, 18 and 22/2019). A detailed analysis has been carried out using 16 serum samples from collected 10 patients with JE reported in Japan. These patients were diagnosed by detection of IgM using IgM-capture ELISA and by neutralization test. In this study, one serum sample showed a positive reaction in TBE IgM-ELISA and eight sera were positive in an IgG-ELISA. Cross-reactivity was also shown with sera from West Nile virus and Dengue virus. However, in a neutralization test, all sera were specific for JE and showed no positive cross-reactivity with TBE virus.
TBE is prevalent in some parts of Japan, and it has also been shown that sera from TBE patients have cross-reactivity with JEV. Therefore, differential diagnosis must be carried out by neutralization test.