Subject(s)
Antibodies, Viral/blood , RNA, Viral/blood , Travel , West Nile Fever/diagnosis , West Nile virus/isolation & purification , Aged , Antibodies, Viral/cerebrospinal fluid , Female , Humans , RNA, Viral/cerebrospinal fluid , West Nile Fever/blood , West Nile Fever/classification , West Nile Fever/virologyABSTRACT
Long-term neurocognitive and functional impairments following West Nile virus (WNV) disease are poorly understood. We assessed quality-of-life indices and neurocognitive performance in a cohort of 54 persons recovering from one of three WNV disease syndromes (fever [WNF], meningitis [WNM], or encephalitis [WNE]) approximately 1.5 years following acute illness. We compared findings between the three syndromic groups; the study cohort and a demographically similar group of 55 controls from a study of chronic fatigue syndrome (CFS); and the study cohort and a 'normative' control population based on cognitive test data. Persistent symptoms, diminished quality of life, and functional impairment were reported by 50% of WNF patients, and 75% each of WNM and WNE patients. Overall, objective neurocognitive performance did not differ significantly between the three syndromic groups, or between the study cohort and the CFS controls or the normative controls. In some neurocognitive subtests, the study cohort scored below the 15th percentile when compared with normative control data. Most persons who returned to independent living following hospitalization for WNV illness had persistent subjective complaints, but had normal cognitive function. However, a minority displayed subtle neurocognitive deficits more than 18 months following acute disease.
Subject(s)
Cognition Disorders/etiology , Mental Processes/physiology , Outcome Assessment, Health Care , Recovery of Function/physiology , West Nile Fever/complications , Adult , Aged , Aged, 80 and over , Analysis of Variance , Attention/physiology , Cognition Disorders/virology , Cohort Studies , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Problem Solving/physiology , Reaction Time/physiology , Recognition, Psychology/physiology , Surveys and Questionnaires , West Nile Fever/classificationABSTRACT
West Nile virus (WNV) has recently been associated with a syndrome of acute flaccid paralysis. Most cases of WNV-associated weakness have clinical, histopathologic, and electrophysiologic characteristics indistinguishable from those of poliomyelitis caused by infection with poliovirus. There is debate about the nomenclature of this manifestation of WNV infection. An historical perspective of the term "poliomyelitis" suggests that the term "WNV poliomyelitis" seems appropriate, but members of the neurologic and infectious disease communities should engage in discussion regarding the terminology of this syndrome.
Subject(s)
Poliomyelitis/classification , Terminology as Topic , West Nile Fever/classification , West Nile virus/pathogenicity , Guillain-Barre Syndrome/etiology , Guillain-Barre Syndrome/virology , Humans , Muscle Hypotonia/etiology , Myelitis, Transverse/etiology , Myelitis, Transverse/virology , Poliomyelitis/virology , PoliovirusABSTRACT
After the 1999 outbreak of West Nile (WN) encephalitis in New York horses, a case definition was developed that specified the clinical signs, coupled with laboratory test results, required to classify cases of WN encephalitis in equines as either probable or confirmed. In 2000, 60 horses from seven states met the criteria for a confirmed case. The cumulative experience from clinical observations and diagnostic testing during the 1999 and 2000 outbreaks of WN encephalitis in horses will contribute to further refinement of diagnostic criteria.
Subject(s)
Disease Outbreaks , Horse Diseases/physiopathology , West Nile Fever/veterinary , West Nile virus/physiology , Animals , Antibodies, Viral/blood , Antibodies, Viral/cerebrospinal fluid , Brain/pathology , Brain/virology , Chlorocebus aethiops , DNA, Viral/analysis , Horse Diseases/classification , Horse Diseases/epidemiology , Horse Diseases/immunology , Horses , Rabbits , Reverse Transcriptase Polymerase Chain Reaction , United States/epidemiology , Vero Cells , West Nile Fever/classification , West Nile Fever/epidemiology , West Nile Fever/physiopathology , West Nile virus/genetics , West Nile virus/immunology , West Nile virus/isolation & purificationABSTRACT
The ultimate extent of West Nile virus's range in North America is uncertain but is likely to expand in 2001. Spread chiefly by night-biting Culex mosquitoes, the virus results in infection that most often is asymptomatic or causes a self-limited febrile illness. The elderly, however, are prone to develop neurologic manifestations, including potentially fatal encephalitis.