Sero-diagnosis of Japanese encephalitis and Dengue virus infection from clinically suspected patients of Nepal

Abstract

Japanese encephalitis (JE) and other viral encephalitis are usually not confirmed in the laboratory in Nepal. However, every year during rainy and post -rainy season in Southern Nepal, from east to west, JE and other viral disease suspected patients become prevalent. The currently available methods for the laboratory diagnosis of JE
and dengue virus infections (DVI) (e.g., serology, and virus isolation) are difficult and
often tedious to carry out as well as time consuming. So, there is a need for serodiagnosis of viral infections to identify the type of infection (JE, DVI or other viral
diseases). The use of conventional methods, however, causes confusion due to the cross-reactions between JE and DVI. In our study, the detection of virus-specific IgM has been proved to be useful for early diagnosis of JE and DVI even with the use of a single
specimen. We applied ELISA to differentiate JE from DVI by detecting IgM specific to
JEV antigen and IgM specific to dengue antigen. From the 279 patients, 244 serum and
35 cerebrospinal fluid (CSF) samples were collected and examined with ELISA using
two different antigens for JE and DVI. The results showed that 28.7% were positive for
JE- IgM antibodies and 10.4% positive for DVI-IgM antibodies.
In addition, JEV-specific IgM antibody detection by Indirect IgM-ELISA and IgMcapture ELISA was also compared in the study.