Smithsonian and Audubon Host Summit on West Nile Virus

Reprinted from the Audubon News mailing list, courtesy of Bill Lowry, U.S. Department of Agriculture and U.S. Geological Survey. Also Serve as Sponsors

In response to the alarming spread of West Nile virus in North America and its potential for taking a severe toll on bird and wildlife populations, the Smithsonian Environmental Research Center (SERC) and the National Audubon Society hosted a summit February. 5–6 for about 100 scientists at SERC’s Edgewater, MD, facility.

The two-day workshop, titled “Impacts of West Nile Virus on Wildlife Health,” was co-chaired by Peter Marra of SERC and Robert McLean of the National Wildlife Research Center of the U.S. Department of Agriculture. The summit, which was also co-sponsored by the USDA and U.S. Geological Survey, was attended by scientists from many different disciplines. These scientists outlined a series of steps that need to be taken to understand West Nile Virus and its effects on people and wildlife.

“ West Nile virus is one of the most serious invasive pathogens to enter this country in the past century,” says Marra, an animal ecologist at SERC. “This meeting was the first of its kind coordinating government agencies, academic institutions, non-profits, and others to think about West Nile virus and other emerging diseases as threats to wildlife populations. We were able to bring together researchers and scientists to prioritize and coordinate research efforts, and to work to standardize methodologies to determine the effects of this virus on wildlife.”

Scientists discussed, with some urgency, the threat West Nile poses to our native bird populations. “West Nile has infected more than 100 bird species, and has killed countless numbers of birds and other wildlife,” says Audubon Senior Vice President of Science Frank Gill. “The virus adds yet another life-threatening challenge to the existence of North American birds at a time when they are under severe stress from other problems. If we are to protect our great natural heritage, then we must first learn all that we can about West Nile virus. Last week’s meeting was a big step forward.”

West Nile virus potentially threatens many endangered species, including scrub jays, whooping cranes, condors, prairie chickens and red-cockaded woodpeckers, to name a few.

West Nile virus, endemic to Africa, Eastern Europe, Western Asia and the Middle East, but not the Western Hemisphere, hit New York in 1999 and spread at an alarming rate both geographically and regarding the number of humans and animals affected. The disease is most commonly transmitted through the bites of infected mosquitoes, although host-to-host (i.e., human-to-human, bird-to-bird) transmission has now been confirmed.

Understandably, much of the focus on West Nile has been on its human impact. But the virus has had a more detrimental effect on bird and animal populations, according to researchers. Wild bird mortality has aided public health agencies in tracking the path of the West Nile pathogen and continues to provide an early warning system for the emergence of the virus in new locations.

The scientists gathered at SERC-including ornithologists, virologists, epidemiologists, entomologists, and others-convened to prioritize and coordinate research to study and combat the impacts of the virus on wildlife populations, especially those that are threatened or endangered, prior to the next transmission season-spring through autumn. Participants represented both public and private organizations; a full list of the organizations involved is attached. The group set several research priorities, including the need to determine: how the virus spreads geographically, how it is transmitted from host to host, how the virus overwinters, how to assess its impact on birds and wildlife, and how we might intervene successfully.

Because it is difficult to predict where West Nile will show up next, it is difficult to plan intervention. “There also needs to be more research on understanding the complexity of the disease and how the pathogen works,” Marra adds. “Until we understand the basic transmission cycle, there’s little we can do to stop it. There’s still a lot to learn; there’s so much we don’t know.”

The extent and impact on wildlife health is difficult to measure and quantify, says Robert McLean of the National Wildlife Research Center. Hundreds of thousands of birds, mammals and reptiles throughout the United States have died. “West Nile virus appears to be indiscriminate in how it affects groups of organisms,” McLean says, “and it is very efficient in what it does.” “We know that some local bird populations have been affected by West Nile Virus,“ said Christopher Brand, a wildlife disease scientist for the U.S. Geological Survey. “But on a regional or continent-wide basis, we don’t know what the long-term ramifications are, especially to threatened or endangered species, where even small geographic-scale disease outbreaks could be disastrous.”

West Nile virus has been found in Canada, Mexico, and in all but four of the continental United States. The concern is that it will eventually spread to Hawaii, the Caribbean and Central America where wildlife is already threatened from a host of other effects.

Marra says the scientists will continue to cooperate and collaborate on the above points of action and will meet again in 18 months to reassess the situation. For workshop information, visit the Avian Ecology web site.