Use of Interferon-α in Patients with West Nile Encephalitis: Report of 2 Cases

We describe 2 patients with West Nile virus (WNV) encephalitis who were treated experimentally with interferon (IFN)– a. Both patients demonstrated substantial improvement in mentation and speech on the second day of experimental therapy, and neither required endotracheal intubation or admission to the intensive care unit during hospitalization. Moreover, during the 9-month follow-up period, one patient achieved complete recovery, and the other nearly achieved complete resolution of sequelae. To our knowledge, this is the first published report of the use of IFN-a to treat WNV encephalitis. Clinical trials are underway to further define the role of this therapy in persons with WNV encephalitis. West Nile virus (WNV) is a single-stranded RNA virus that is sustained in a natural cycle involving mosquitoes and birds but that also infects humans, horses, and other animals. The first US outbreak was described in 1999, when 66 people received