Diagnosis of Jamestown Canyon encephalitis by polymerase chain reaction

In recent years, polymerase chain reaction (PCR) has been under study as a potential technique to improve the accuracy of diagnosis of suspected centr al nervous system viral infections. We describe a case of severe encephalit is in a previously healthy 20-year-old woman from New York who presented wi th headache, fever, and photophobia. Her illness was characterized by progr essive worsening of her neurological status, leading to confusion, delirium , and status epilepticus. The diagnosis of Jamestown Canyon encephalitis wa s established by positive reverse transcriptase (RT)PCR and nucleic acid se quencing of the band from both cerebrospinal fluid and brain tissue. The nu cleotide sequence and the deduced amino acid sequence of the Jamestown Cany on virus from this patient were very similar to Jamestown Canyon virus isol ates from mosquito pools in New York. This report suggests that RT-PCR assa ys could be important tools in the diagnostic workup of cases of encephalit is.