West nile virus history and symptoms
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
The presentation of patients with West Nile fever infection is variable as it can be completely asymptomatic, mild, or very severe. When symptoms are present, the manifestation of West Nile fever infection can range from mild fever, to severe encephalitis, meningitis, coma, and death.
History
Symptoms
West Nile fever infection can present with a variety of manifestation according to the severity of the diseases. West Nile fever infection has three different clinical presentations in humans: asymtomatic, mild febrile syndrome termed West Nile fever, and Neuroinvasive disease termed West Nile meningitis or encephalitis.
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
West Nile encephalitis
West Nile meningitis
Constitutional Symptoms
- High fever
- Body aches
Neurological
It is the most severe form of the disease. They can present with a variety of manifestation in conjunction with fever like meningitis, flaccid paralysis, encephalitis or a combination of these . The most common neurological symptoms with their corresponding frequencies are tabulated below.
| Symptom | Percentage |
|---|---|
| Facial Palsy | 13% |
| Dhyphagia | 33% |
| Dysarthria | 33% |
| Diplopia | 33% |
| Tremor | 22% |
| Parkinsonism | 16% |
| Ataxia | 31% |
| Motor seizures | 5% |
| Myoclonus | 31% |
- Deep tendon reflexes are hyperactive at first, later diminished. There are also extrapyramidal disorders. Recovery is marked by a long convalescence with fatigue. More recent outbreaks have resulted in a deeper study of the disease and other, rarer, outcomes have been identified.The spinal cord may be infected, marked by anterior myelitis with or without encephalitis.[1] WNV-associated Guillain-Barré syndrome has been identified[2]
West nile meningitis
The main signs and symptoms are back pain, myalgia, rash , photophobia. Usually it is aseptic meningitis and resolves without major complications.
West nile meningoencephalitis
It is the most common form of severe disease presenting as behavioual changes like confusion, irritability, disorientation along with focal signs like tremor, ataxia , bulbar dysfunction, or focal weakness.
Acute flaccid paralysis
It usually occurs in the subclinical phase presenting as lower limb weakness with flaccid tone, areflexia or hyporeflexia.
Multiorgan abnormality
- Chorioretinitis (which has 100% specificity for identifying WNV infection in patients with possible WNV encephalitis)[3]
- Hepatitis
- Myocarditis
- Nephritis
- Pancreatitis
- Splenomegaly.[4][5][6]
References
- ↑ Sejvar J J, Haddad M B, Tierney B C, Campbell G L, Marfin A A, VanGerpen J A, Fleischauer A, Leis A A, Stokic D S, Petersen L R. "Neurologic manifestations and outcome of West Nile virus infection." JAMA 2003; 290: 511-515.
- ↑ Ahmed S, Libman R, Wesson K, Ahmed F, Einberg K. "Guillain-Barre syndrome: an unusual presentation of West Nile virus infection." Neurology 2000; 55: 144-146.
- ↑ 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.