Persistent West Nile Virus Infection?

First detected in North America just 10 years ago, West Nile virus (WNV) has profoundly affected the differential diagnosis and management of several acute neurological syndromes seen among patients in the U.S. Researchers have shown evidence of persistent WNV infection in experimentally infected animals, but not — until now — in humans.

Since 2002, investigators in Houston have prospectively monitored patients (currently numbering 112) who had been hospitalized with acute WNV infection. Every 6 months, the patients undergo blood testing and complete a questionnaire to allow assessment of long-term outcome. These patients commonly report chronic symptoms. The deaths of five participants from renal failure led the researchers to suspect persi…