February 1983

Powassan Virus Encephalitis Resembling Herpes Simplex Encephalitis

Author Affiliations

From the Departments of Microbiology (Dr Embil) and Pediatrics (Drs Embil and Camfield), Dalhousie University, Halifax, Nova Scotia; the Infectious Diseases Research Laboratory, Izaak Walton Killam Hospital for Children, Halifax, Nova Scotia (Dr Embil and Mr Chase); and the National Arbovirus Reference Service, Department of Medical Microbiology, University of Toronto (Dr Artsob).

Arch Intern Med. 1983;143(2):341-343. doi:10.1001/archinte.1983.00350020167030

• A boy from New York traveling in Nova Scotia had olfactory hallucinations and other signs of temporal lobe involvement, leading to a diagnosis of herpes simplex encephalitis. The patient was treated with vidarabine and made a complete recovery. However, hemagglutination inhibition, complement fixation, and neutralization tests identified Powassan virus (POW) as the pathogen. Shortly before his trip to Nova Scotia, the patient had traveled in an area where POW encephalitis had occurred in humans (the eastern part of the state of New York), and he also came in contact with a known reservoir of POW infection (a groundhog) at home.

(Arch Intern Med 1983;143:341-343)