West Nile Virus Infection Presenting as Cerebellar Ataxia and Fever: Case Report

IMPORTANCE Since its introduction in North America in 1999,West Nile virus has produced the 3 largest arboviral neuroinvasive disease outbreaks ever recorded in the United States. OBJECTIVE To review the ecology, virology, epidemiology, clinical characteristics, diagnosis, prevention, and control of West Nile virus, with an emphasis on North America. EVIDENCE REVIEW PubMed electronic database was searched through February 5, 2013. United States national surveillance data were gathered from the Centers for Disease Control and Prevention. FINDINGS West Nile virus is now endemic throughout the contiguous United States, with 16 196 human neuroinvasive disease cases and 1549 deaths reported since 1999. More than 780 000 illnesses have likely occurred. To date, incidence is highest in the Midwest from mid-July to early September. West Nile fever develops in approximately 25% of those infected, varies greatly in clinical severity, and symptoms may be prolonged. Neuroinvasive disease (meningitis, encephalitis, acute flaccid paralysis) develops in less than 1% but carries a fatality rate of approximately 10%. Encephalitis has a highly variable clinical course but often is associated with considerable long-term morbidity. Approximately two-thirds of those with paralysis remain with significant weakness in affected limbs. Diagnosis usually rests on detection of IgM antibody in serum or cerebrospinal fluid. Treatment is supportive; no licensed human vaccine exists. Prevention uses an integrated pest management approach, which focuses on surveillance, elimination of mosquito breeding sites, and larval and adult mosquito management using pesticides to keep mosquito populations low. During outbreaks or impending outbreaks, emphasis shifts to aggressive adult mosquito control to reduce the abundance of infected, biting mosquitoes. Pesticide exposure and adverse human health events following adult mosquito control operations for West Nile virus appear negligible. CONCLUSIONS AND RELEVANCE In North America, West Nile virus has and will remain a formidable clinical and public health problem for years to come.

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“…Cerebellar ataxia, increased intracranial pressure, cerebral edema, and seizures have been described but are uncommon. 43,44,46 …”

Section: Infection and Illnessmentioning

confidence: 99%

West Nile Virus: Review of the Literature

Petersen

Brault

Nasci

2013

JAMA

601

572

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“…Features of parkinsonism, including hypomimia, bradykinesia and postural instability, may be seen and can be associated with falls and functional difficulties [3,23]. Cerebellar ataxia, with associated truncal instability and gait disturbance, leading to falls, has been described [6,22,24]. These abnormal movements usually follow the onset of mental status changes.…”

Section: Clinical Syndromes Associated With Wnv Infectionmentioning

confidence: 99%

Clinical Manifestations and Outcomes of West Nile Virus Infection

Sejvar

2014

Viruses

206

177

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Since the emergence of West Nile virus (WNV) in North America in 1999, understanding of the clinical features, spectrum of illness and eventual functional outcomes of human illness has increased tremendously. Most human infections with WNV remain clinically silent. Among those persons developing symptomatic illness, most develop a self-limited febrile illness. More severe illness with WNV (West Nile neuroinvasive disease, WNND) is manifested as meningitis, encephalitis or an acute anterior (polio) myelitis. These manifestations are generally more prevalent in older persons or those with immunosuppression. In the future, a more thorough understanding of the long-term physical, cognitive and functional outcomes of persons recovering from WNV illness will be important in understanding the overall illness burden.

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“…In our case, the MRI of the spinal cord including the roots showed no signal abnormalities and the CSF did not show cytoalbumin dissociation; so the patient's clinical features can be explained only by the anterior horn cell involvement. Moreover, MRI signal abnormalities in the anterior spinal cord had been noted in patients with poliomyelitis [6,11,12] ; however, these fi ndings are inconsistent [11,13,14] and the absence of such changes in our patient in whom Introduction West Nile virus (WNV) infection is a mosquito-borne fl avivirus febrile illness seen in Africa, Asia, Europe and North America. In autumn 1997, an epidemic WNV outbreak occurred in two coastal districts of Tunisia, 173 patients were hospitalized for meningitis and encephalitis [1] .…”

mentioning

confidence: 53%