Diagnosis and treatment of west nile infections.

West Nile Virus (WNV) should be considered in the differential diagnosis for patients presenting with symptoms of viral meningitis, encephalitis, and flaccid paralysis. The activity for 2003 started with human cases in July and is expected to continue spreading throughout the United States. Only 1 in 150 WNV infections result in severe neurologic illness, which is more common in the elderly population. Testing for the IgM antibody against WNV in both serum and spinal fluid is the diagnostic test of choice. Treatment is generally supportive, and no specific anti-viral agents have been determined in trials to be beneficial. Prevention includes the elimination of mosquito breeding sites and the use of pesticides and insect repellents.