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]
Overview
West Nile fever infection can present with a variety of manifestations depending to the severity of the diseases. West Nile fever infection has three different clinical presentations in humans: 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 West Nile virus infection should be inquired about any recent mosquito bites.
History
Patients who are suspected to have West Nile virus infection should be inquired about any recent mosquito bites. In addition, important clues in the history include the time of the year, geographical location, recent travel, and outdoor activities. The patient should be asked about the presence of symptoms and their progression.
Symptoms
Asymptomatic
Absence of symptoms is present in approximately 80% of subjects infected with the West Nile virus.
West Nile Fever
Constitutional Symptoms
Skin Symptoms
- Skin rash on the trunk of the body
- Swelling of lymph nodes
Gastrointestinal Symptoms
Neurovascular Disease
Neurovascular involvement is the most severe form of West Nile virus infection. Patients can present with a variety of manifestation in conjunction with fever such as meningitis, flaccid paralysis, encephalitis or a combination of these conditions.
Constitutional Symptoms
- High fever
- Body aches
Neurological Symptoms
Shown below is a table of the most common neurological symptoms with their corresponding frequencies.
| 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
Acute Flaccid Paralysis
- Lower limb weakness
Multiorgan Involvement
- Chorioretinitis (100% specificity for identifying West Nile virus infection in patients with possible West Nile virus encephalitis)[1]
- Hepatitis
- Myocarditis
- Nephritis
- Pancreatitis
- Splenomegaly[2][3][4]
References
- ↑ 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.