Faster West Nile diagnostic test gets FDA nod

The rapid-acting blood test is indicated for patients with encephalitis or meningitis.

By Susan J. Landers, AMNews staff. Sept. 1, 2003.

Washington -- The Food and Drug Administration has approved a new rapid-acting test for West Nile virus just as the number of mosquitoes carrying the potentially deadly virus peaks in the United States.

As of mid-August, the Centers for Disease Control and Prevention reported 446 human cases of West Nile with 10 deaths. Last year 4,156 people were infected and 284 died.

Nearly half the states are reporting human West Nile virus cases so far this year with the majority in Colorado, which is reporting 247 cases including six deaths. Colorado reported no human cases last year.

The new test, developed by PANBio an Australian medical diagnostics company, takes about two hours to detect antibodies to the virus in the patient's blood. Earlier tests took two days, and there was often a backlog of cases pushing the waiting time for results to as long as two weeks.

The test, West Nile Virus IgM Capture ELISA, is intended for use in patients with clinical symptoms of viral encephalitis or meningitis. It costs about $25.

The new test was evaluated on more than 1,000 patients at four clinical sites and correctly identified antibody in 90% to 99% of West Nile virus cases, according to the FDA. However, given similarities with other viruses, there is still a need to confirm positive results with an additional test.