Scientists from the U.S. Geological Survey said recently that the West Nile Virus can be transmitted from bird-to-bird in a confined laboratory setting. It had been thought that the virus was only transmitted through mosquito bites.

Scientists from the USGS National Wildlife Health Center in Madison, Wisc., placed infected birds in the same biocontainment (BL3) aviary as healthy birds. The infected birds died five to eight days later. Most of the healthy birds, the researchers found, also became ill from the virus and died five to eight days after the first infected bird died.

“It confirms a suspicion that we had and wanted to verify,” said Dr. Robert McLean, director of the USGS National Wildlife Health Center. “The setting was a very controlled scientific experiment and we’re not sure if or how this relates to what is happening in the wild. Mosquitoes are the primary means of transmission of the virus between birds and to humans. But this certainly opens up a host of new questions.”

Chief among the questions, McLean said, is exactly how the virus moves from bird to bird. He said he and other scientists are working on that question now