New York The government has approved the first national trial of a drug to treat the West Nile virus, which has killed at least 31 people since it was first detected in the United States three years ago.
The testing of alpha-interferon will begin immediately at New York Hospital Queens, in the borough where the mosquito-borne virus was first found in the country.
Dr. James Rahal, the study's chief investigator, said 40 people age 50 and older who have been hospitalized with the virus will be enrolled in the study. Patients across the country can enroll, but the trial most likely will focus on Louisiana and Mississippi, where 10 West Nile deaths have been confirmed this year.
Alpha-interferon is sold as Intron A for treatment of hepatitis C by Schering-Plough, which is paying for the study.
Tests have shown interferon to be effective in lessening the symptoms and length of hepatitis. It has also proven effective against St. Louis encephalitis, a virus similar to West Nile. There is no known treatment for West Nile virus.
Rahal said Wednesday that he treated 15 Louisiana patients with the drug to make sure it was safe for those with West Nile.
He said the results were promising enough to get the Food and Drug Administration to approve the new trial.
"Encouraging," he said. "Not convincing, but encouraging."
The West Nile virus is passed on to humans by mosquitoes that have bitten infected birds. Government researchers say less than 1 percent of people who are bitten will become severely ill.
Those who do suffer flu-like symptoms and, in the worst cases, encephalitis, a potentially fatal inflammation of the brain.
The study will target patients whose virus is still in the blood, where it circulates before entering the brain, Rahal said. Therefore, patients must begin treatment within the first four days of being admitted.
"Once damage has occurred in the brain, it's not likely to be reversible, at least not by a drug," Rahal said. "What we want to do is increase the body's defense against the virus, and decrease the amount of virus that ultimately enters the brain or the nervous system."
The protocol calls for two weeks of interferon, whose side effects include a decrease in the white blood count and inflammation of the liver both reversible once the drug is stopped.
Rahal said long-term use could cause depression, confusion and fatigue.