West Nile virus (WNV) is a neurotropic flavivirus that has emerged globally as a significant cause of viral encephalitis. Infection of humans is associated with a febrile illness that can progress to a lethal encephalitis with symptoms including cognitive dysfunction and flaccid paralysis. Seroprevalence studies suggest that while the majority of WNV infections are asymptomatic, approximately 20 to 30% of infected individuals develop flu-like clinical manifestations characterized as WNV fever.
Disease Statistics: In 2012, most human cases of WNV infection occurred in norway areas that had been affected also in 2010 and 2011. However, in 2012, a markedly higher incidence of WNV infection was observed than in previous years, with 25 cases of WNND, 17 cases of WNF, 14 WNV RNA-positive blood donors, and further two cases of asymptomatic WNV infection identified by active surveillance of subjects at risk of WNV exposure.
Diagnosis: In most instances, physicians can diagnose West Nile virus by analyzing a blood sample. A simple blood test can determine whether you have genetic material or antibodies associated with West Nile virus in your blood. If your symptoms are severe and brain-related, your physician may order a lumbar puncture. Also known as a spinal tap, this test involves inserting a needle into your spine to extract fluid.
Treatment: The diagnosis of West Nile virus infection is confirmed with a blood or cerebrospinal fluid test. There is no specific treatment for West Nile virus infection. Intensive supportive therapy is directed toward the complications of brain infections. Anti-inflammatory medications, intravenous fluids, and intensive medical monitoring may be required in severe cases.