A Brief Report of West Nile Virus Neuroinvasive Disease in the Summer of 2012 in Hamilton, Ontario

Lei Jiao,Cheryl Main

doi:10.1155/2014/626783

Abstract

West Nile neuroinvasive disease is a severe infectious disease that is associated with a high mortality rate, especially in immunocompromised hosts. Physicians who are aware of its clinical presentations may be able to order diagnostic tests more appropriately and avoid inappropriate treatment. In the present series, the cases of seven patients admitted to Hamilton Health Sciences (Hamilton, Ontario) in the summer of 2012 with a diagnosis of West Nile neuroinvasive disease were retrospectively reviewed based on available medical records. According to the clinical and laboratory criteria published by the Centers for Disease Control and Prevention, five cases were diagnosed as encephalitis, one case as meningitis and one case as meningomyelitis. Patients were managed supportively. Forty-three percent (three of seven) presented with rash, 71% (five of seven) did not report headache despite exhibiting neurological symptoms, 43% (three of seven) did not have fever on presentation and 37.5% of cerebrospinal fluid samples exhibited a neutrophil predominance. The mortality rate in the present series was 14.3% (one of seven), and 57.1% (four of seven) of the patients had residual symptoms on discharge and at follow-up.

Highlights

West Nile neuroinvasive disease is a severe infectious disease that is associated with a high mortality rate, especially in immunocompromised hosts
Less than 1% of infected individuals develop West Nile neuroinvasive disease (WNND), which is categorized as aseptic meningitis, encephalitis or acute flaccid paralysis [3]
According to the clinical and laboratory criteria published by the Centers for Disease Control and Prevention (Georgia, USA) [3], WNND was defined by the presence of acute neurological illness and laboratory evidence of West Nile Virus (WNV) infection including WNV-specific immunoglobulin M (IgM) antibody detected by ELISA, and a confirmatory plaque reduction neutralization test in acute-phase cerebrospinal fluid (CSF) or serum samples

Summary

Introduction

West Nile neuroinvasive disease is a severe infectious disease that is associated with a high mortality rate, especially in immunocompromised hosts. The cases of seven patients admitted to Hamilton Health Sciences (Hamilton, Ontario) in the summer of 2012 with a diagnosis of West Nile neuroinvasive disease were retrospectively reviewed based on available medical records. Le cas de sept patients hospitalisés au Hamilton Health Sciences de Hamilton, en Ontario, pendant l’été 2012 en raison d’un diagnostic de maladie neuro-invasive du Nil occidental a fait l’objet d’une analyse rétrospective d’après les dossiers médicaux disponibles. The majority of infected individuals are asymptomatic, while 20% may present with West Nile fever, with symptoms ranging from generalized malaise, mild fever, headache, arthralgia and nausea, to maculopapular rash [2]. Less than 1% of infected individuals develop West Nile neuroinvasive disease (WNND), which is categorized as aseptic meningitis, encephalitis or acute flaccid paralysis [3]. The clinical symptoms, radiological imaging, serological diagnosis, treatment and prognosis in this group of patients are summarized

Methods

Results

Conclusion