ONE REASON THAT health experts emphasize prevention of West Nile virus is that at the present time there is no specific treatment for the illness. That is, there are no known medications or therapies that can eradicate the virus. Antibiotics, used to treat bacterial infections, are ineffective against viruses. Several patients hospitalized with West Nile virus-related fever, chills, body aches, encephalitis, or meningitis have been given antibiotics before doctors knew they had West Nile virus, and these medications did not help the patients' conditions. Doctors have also tried using ribavirin and interferon on patients severely ill with West Nile virus infection. Ribavirin is an antiviral medication that kills West Nile virus in a laboratory test tube and is effective against several other flaviviruses in humans. Interferon is a natural immune-system chemical that can be...