June 7, 2004

Conference signals growth of disease ecology field


By Michael Terrazas

Emory hosted a conference in May devoted to a rapidly growing discipline that offers new approaches and insights for understanding emergent biological threats.

Titled the “Evolution and Ecology of Infectious Disease Meeting” and held May 19–23 at the Emory Conference Center, the event was the second such international gathering of “disease ecologists,” who approach infectious disease from a perspective different than the traditional clinical and public-health models. The event was sponsored by the Center for Disease Ecology (CDE), directed by Les Real, Asa G. Candler Professor of Biology. Sonia Altizer, assistant professor of environmental studies, co-organized the conference with Real.

Both professors attended last year’s first such gathering, held at Penn State University, and they said the conference gave researchers and graduate students the opportunity to share cutting-edge research in a field of increasing national and global importance, as well as connect with a small but expanding network of colleagues. About 100 people from roughly 30 institutions attended, participating not just in lectures and colloquiua but also after-hours social events and a hike in the north Georgia mountains.

“This kind of opportunity for informal interaction doesn’t exist at the larger conferences and scientific meetings,” Real said. “It allows graduate students and post-docs to form a collaborative network to develop their research and pursue their careers.”

There’s a reason disease ecology is a hot field. In the post-Sept. 11 world, biologic threats are very real, and the conference’s cosponsors reflect this; in addition to the Graduate School of Arts and Sciences and the Office of Research, the event also was sponsored by the Center for Public Health Preparedness and Research (CPHPR), and the Southeastern Center for Emerging Infections and Biodefense.

“Our center works a lot on emerging infectious diseases and bioterrorism, and we think disease ecology is important to both issues,” said Ruth Berkelman, Rollins Professor of Epidemiology and CPHPR director, who attended the conference and called it superb. “There are a lot of issues around pathogen/environment interaction that we haven’t known about in the past.”

Disease ecology as a discipline is well represented at Emory. Of the 33 graduate faculty in the Population Biology, Ecology and Evolution (PBEE) graduate program, for example, Real estimated roughly 25 have a stated in interest in disease ecology, and about half of those are adjunct faculty employed at the CDC. Neither Real nor Altizer could estimate how many disease ecologists are working nationwide, but they said both the National Science Foundation and the National Institutes of Health are spearheading programs in the field.

“You’re starting to see it advertised as a specialty,” Altizer said, “which you didn’t see even five years ago.”

What distinguishes disease ecology is its focus on disease-causing agents as they evolve and move across ecological landscapes. Zoonotic diseases, for example—those migrating from animal to human hosts, such as HIV—are tailor-made for disease ecology. Researchers study not only the interaction between the pathogen and an individual host, but also how the pathogen evolved between its wildlife and human hosts, how humans came into contact with the animal hosts, and any genetic shifts in the pathogen.

“At the conference, people were all thinking about the same problems but in different systems,” Altizer said. “One speaker talked about studying rabies in the Serengeti ecosystem to understand interactions between domesticated dogs and native carnivores. Another talked about flower pathogens crossing host species barriers, which can serve as a model for sexually transmitted diseases.”

Founded in 2000, the CDE is the first such center in the country, Real said, though he added Penn State is about to open its own. Emory benefits from its proximity to the CDC; because of the close relationship between the institutions, Emory graduate students will soon be able to conduct lab rotations and thesis research at CDC sites in New Mexico, India, Kenya and Venezuela. Also, the PBEE graduate program just received a five-year, $900,000 grant from the NIH specifically to train graduate students in disease ecology.

“Disease ecology merges key ideas from ecology, medicine, genetics, immunology and epidemiology,” Real said. “We can study how hosts and pathogens interact in populations, communities and even entire ecosystems.”