Detection of West Nile and Japanese Encephalitis Viral Genome Sequences in Cerebrospinal Fluid from Acute Encephalitis Cases in Karachi, Pakistan

Abstract
Reverse transcriptase-polymerase chain reaction (RT-PCR) on 24 cerebrospinal fluid (CSF) specimens collected between February and August 1992 detected genome sequence of West Nile (WN) virus in 8 specimens and Japanese encephalitis (JE) virus in a single specimen. The results, combined with the data by IgM-ELISA on CSF indicated that a significant proportion of acute encephalitis cases in Karachi, Pakistan, were caused by WN virus infection, while JE virus caused a small fraction.