Jpn. J. Infect. Dis., 58 (5), 294-296, 2005
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Original Article
Detection of Japanese Encephalitis (JE) Virus-Specific IgM in Cerebrospinal Fluid and Serum Samples from JE Patients
Sumalee Chanama*, Walailuk Sukprasert, Areerat Sa-ngasang, Atchareeya A-nuegoonpipat, Somchai Sangkitporn, Ichiro Kurane1 and Surapee Anantapreecha
National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi 11000, Thailand and 1Department of Virology I, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
(Received April 25, 2005. Accepted August 15, 2005)
*Corresponding author: Mailing address: National Institute of Health, Department of Medical Sciences, Ministry of Public Health, 88/7, Tivanond Road, Muang, Nonthaburi 11000, Thailand. Tel: +66 29510000 ext. 99220, Fax: +66 25915449, E-mail: sn111139@dmsc.moph.go.th
SUMMARY: Detection of Japanese enchephalitis virus (JEV)-specific IgM by IgM-capture enzymed-linked immunosorbent assay (IgM-capture ELISA) has been accepted as the standard for serological diagnosis. In the present study, we analyzed the time course of the positive rate of JEV-specific IgM in serum and cerebrospinal fluid (CSF) specimens from confirmed JE patients. Serum and CSF samples were obtained from 155 JE cases for diagnostic purposes at hospitals in Thailand from 2002 to 2004. The levels of specific IgM were assessed by IgM-capture ELISA in the 171 serum and 156 CSF samples. Anti-JEV IgM was detected in 26 of 44 serum samples collected on days 1-4 of the disease period, in 31 of 44 samples collected on days 5-8, in 23 of 26 samples collected on days 9-12, and in all the samples collected on day 13 or later. Specific IgM was detected in 60 of 66 CSF samples collected on days 1-4 of illness, and in all the CSF samples but one collected on day 7 or later. The results indicate that the detection of JEV-specific IgM in CSF by IgM-capture ELISA is a reliable laboratory diagnostic method for confirmation of JE throughout the disease period, while the detection of IgM in serum samples is a reliable method on day 9 or later.