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.
On 9 December 2014, the Ministry of Health of Brazil reported a case of West Nile Virus (WNV) in the state of Piauí (PI). This is the first detection of a human case of WNV infection in Brazil. Four other people presented symptoms; however, laboratory tests ruled out WNV infection. In addition to those with symptoms, tests were performed on 18 other individuals in the area and all results were negative.
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.
The Brazilian Society of Tropical Medicine expressed concern about the circumstances in which the diagnosis of the first case of WNF in Brazil was conducted