Thursday, 31 March 2011

Landscape Ecology, Urban Planning and Disease Prediction/Prevention



Tuesday evening’s event featured an engaging lecture co-presented by Dr. Suzanne Kennedy-Stoskopf and Dr. Chris DePerno. Their talk, entitled Changing Landscapes, Changing Populations, Changing Values, Changing Disease Risks: What Is Happening to Wildlife? covered the natural history of several North Carolina wild animals and their potential to spread infectious disease.

Dr. Kennedy-Stoskopf, a research professor at NC State University, began the presentation by discussing humanity’s intrinsic connection to animals; she remembered, as many of use do, being interested in animals from a young age. She reminded the audience that in spite of this connection, animals do pose a risk to human well being; 60.3% of emerging infectious diseases are zoonosis, and 71.8% originate in wildlife. A lively discussion ensued around what these numbers meant to audience members—some of the more interesting points raised included wondering what humans had done to provoke these statistics and how it really represents a false barrier between humans/domestic animals/and wildlife. Dr. DePerno, Associate Professor in the NC State Department of Forestry and Environmental Resources, then took over, highlighting the changes that have occurred in North Carolina over the past century that have led to a proliferation in certain types of wildlife. These included a decrease in hunting, land fragmentation, urban refugees (city-dwellers moving to the country), and a general growth in cities. He also mentioned a tendency for many Americans to have a low tolerance for wildlife; we like it in zoos and the forest, but not in our backyard or the sides of the road.

For the remainder of the talk, Drs. Kennedy-Stoskopf and DePerno focused on specific animals that have been able to thrive in this new environment, which has led to some interesting confrontations with humans. The audience learned that the deer population plummeted in North Carolina from about 1500-1800 because of intensive hunting for their hides. By the early 1900s, less than 10,000 deer were left in North Carolina, and limits on hunting were instated, in addition to a restocking program. Of course, as we can all attest, the program was almost too successful. The biggest risk that deer overpopulation poses to humans is vehicular collisions. Between 2007-2009, there were 17,370 deer-car collisions and 17 fatalities. The other principle risk is vector amplification: deer can spread a number of diseases including tick borne diseases, chronic wasting disease, mycobacterium bovis, and deer parapoxvirus. The appearance of coyotes in North Carolina during the 1970s and 80s was mentioned as another growing issue. While it is unclear how these animals will play into health issues, it is recognized that coyotes are very adaptable and have long home ranges. Another animal of concern is the raccoon, whose population has also increased in numbers since the late 1980s, in part due to a decrease in trapping.

In closing, our two guests told the audience that this kind of change is happening on a global level and at an accelerated rate, a salient point that certainly has implications for those interested in a one health perspective. As the human/wildlife interface continues to expand, and the issue of disease increases, it will be even more important to recognize the human, animal, and environmental aspects of disease.

A number of excellent questions were posed. These included:

· How effective have surveillance systems been in predicting animal diseases likely to transfer to humans?
· In planning for development, could likelihood of becoming a disease hotspot be used as one criteria in evaluating sites?
· Climate change has generally been associated with an increase in EID's. Is there any data that may suggest a negative correlation for outbreaks of a particular disease in certain affected areas? In other words, have we seen less outbreaks of any particular pathogens potentially due to changes in climate?
· A few of the readings called for a focus on the human dimensions of wildlife disease. Has this approach been used on a global scale as well? How would it look as compared to the research they described that had taken place in the US?
· Many emerging infectious diseases are a result of human population growth and invasion of new frontiers. How can we better protect both human beings and animals from the effects of human population growth?
· Since global resources are poorly allocated to areas where disease emergence is less likely, what will it take to shift resources to countries in which emerging infectious diseases are likely to arise?

Thank you to Dr.
Kennedy-Stoskopf and Dr. DePerno for an engaging and informative evening!