Hyperimmune gammaglobulin for the treatment of West Nile virus encephalitis.

Background: West Nile virus, the etiologic agent of West Nile fever, is an emerging mosquito-borne disease. WNV was recognized as a cause of severe human meningoencephalitis in elderly patients during outbreaks in various parts of the world.

Objectives: To analyze WNV encephalitis therapy and its outcome after prescribing hyperimmune gammaglobulin therapy.

Methods: Eight subjects with WNV encephalitis were treated with supportive therapy and 5 days of IVIG 0.4 g/kg/day containing high WNV antibodies obtained from healthy blood donors.

Results: Patients who were treated with IVIG as soon as possible exhibited an improvement in their symptoms. All subjects presented with high fever, progressive confusion and headaches, nausea and vomiting. The Glasgow Coma Screen for six patients ranged between 8 and 13 and all were discharged with a score of 15. The remaining two subjects died during their hospitalization.

Conclusions: In severe WNV infection, where the disease affects the central and/or peripheral nervous system, early intervention with IVIG together with supportive treatment is recommended.