West nile virus history and symptoms
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ammu Susheela, M.D. [2]; Rim Halaby, M.D. [3]
Overview
WNV infection is considered a clinical spectrum. Infection due to WNV may have any of 3 different clinical presentations: Asymptomatic (~70-80%), mild febrile syndrome termed West Nile fever (~20%), and neuroinvasive disease termed West Nile meningitis or encephalitis (<1%). Patients who are suspected to have WNV infection should specifically be inquired about recent mosquito bites.
History
Patients who are suspected to have West Nile virus infection should be inquired about recent mosquito bites. In addition, important clues in the history include the time of the year, geographical location, recent travel, and outdoor activities. Patients should also be asked about virus-associated symptoms and their progression.
Symptoms
Asymptomatic
An asymptomatic course of the disease is observed among approximately 80% of individuals infected with WNV.
West Nile fever
Constitutional symptoms
HEENT symptoms
Gastrointestinal symptoms
Genitourinary symptoms
Cutaneous manifestations
- Macular or papular skin rash on the trunk
- Lymphadenopathy
Neuroinvasive disease
Neuroinvasive disease is the most severe form of WNV infection. Patients can present with fever associated with a wide range of neurological manifestations, such as flaccid paralysis, symptoms of meningitis or encephelatitis, or a combination of these conditions.
Constitutional symptoms
- High fever
- Diffuse body aches
Neurological symptoms
Shown below is a table of the most common neurological symptoms of neuroinvasive WNV disease with their corresponding frequencies.[1]
| Symptom | Percentage |
|---|---|
| Facial palsy | 13% |
| Dysphagia | 33% |
| Dysarthria | 33% |
| Diplopia | 33% |
| Tremor | 22% |
| Parkinsonism | 16% |
| Ataxia | 31% |
| Motor seizures | 5% |
| Myoclonus | 31% |
West Nile meningitis
West Nile meningoencephalitis
- Confusion
- Irritability
- Disorientation
- Tremor
- Ataxia
- Bulbar dysfunction
- Focal weakness
- Sensory loss
- Memory loss
- Diplopia
- Cranial nerve palsy
Acute flaccid paralysis
- Lower limb weakness
Multiorgan involvement
- Chorioretinitis: Very specific for identifying WNV virus infection among patients with high pre-test probability[2]
- Hepatitis
- Myocarditis
- Nephritis
- Pancreatitis
- Splenomegaly[3][4][5]
References
- ↑ "Neurologic Complications of West Nile Virus".
- ↑ Abroug F, Ouanes-Besbes L, Letaief M, Ben Romdhane F, Khairallah M, Triki H, Bouzouiaia N. "A cluster study of predictors of severe West Nile virus infection." Mayo Clinic Proceedings 2006; 81: 12-16.
- ↑ Perelman A, Stern J. "Acute pancreatitis in West Nile Fever." American Journal of Tropical Medicine and Hygiene 1974; 23: 1150-1152.
- ↑ Omalu B I, Shakir A A, Wang G, Lipkin W I, Wiley C A. "Fatal fulminant pan-meningo-polioencephalitis due to West Nile virus." Brain Pathology 2003; 13: 465-472
- ↑ Mathiot C C, Georges A J, Deubel V. "Comparative analysis of West Nile virus strains isolated from human and animal hosts using monoclonal antibodies and cDNA restriction digest profiles." Res Virol 1990; 141: 533-543.