Anyone who pays attention to the news can rattle off diseases that have leapt from animals to people on a spectacular scale. The bird and swine influenzas bear obvious names, as does eastern equine encephalitis. SARS and HIV are examples, too. Katherine Smith pays even closer attention than most as a scholar in the emerging field of “conservation medicine.”
The discipline may be young, but the phenomenon of interspecies disease and environmental change is not, Smith said. Studies in conservation medicine have been relevant for 11,000 years, since people began keeping livestock.
“The dynamics of the way that hosts and pathogens interact with one another really haven’t changed at all for millennia,” said Smith, who has been a researcher at Brown since 2008 but this year joins the faculty as assistant professor of ecology and evolutionary biology. “It’s just that now we are altering the environment in ways that create entirely new opportunities for pathogens to come in contact with novel animal hosts.”
People are deforesting and moving into new areas, altering the climate, and traveling great distances with exotic germs in tow, she said. “Zoonotic” diseases therefore have greater potential to make their debut. Understanding the causes and courses of such outbreaks, either between people and animals or among different animal species, is the focus of Smith’s research and teaching. Her investigations range from the world’s jungles to the neighborhood pet store.
Her newest project, a team effort with computational evolutionary biologist Sohini Ramachandran and global information systems expert Lynn Carlson, is to create a database of all the World Health Organization’s reports on infectious disease outbreaks since the 1980s. There are about 30,000 unique outbreaks. She will combine the WHO’s medical information with environmental and population data to look for linkages and patterns.
One question Smith is eager to answer is whether global warming has changed the geography of tropical diseases. Some experts figure such maladies will expand their range deeper into traditionally temperate latitudes. Others say equatorial regions are becoming so hot and dry that diseases will vacate the lowest latitudes. Smith will have the data to inform if not settle the debate.
Smith is interested in influencing more than just her colleagues, however. Her years of work studying the travels of pathogens within the global wildlife trade have naturally resulted in a desire to see the trade improve. In her research, which has focused on reptiles and ornamental fishes, Smith has found that undue stress during life as a consumer product can sometimes upset the natural balance animals have with the microbes that live in them.
“There is no such thing as a salmonella-free reptile,” Smith said. “Typically it’s just a normal member of the microflora that these animals carry. But we’ve learned that when reptiles are in the pet trade and they are increasingly stressed out, the bacteria proliferate, and it almost inundates their system. Stressed animals equal sick animals.”
Such findings inspired her to start PetWatch, a website run by the EcoHealth Alliance. The site provides consumers with information on whether a particular species is being sourced sustainably, is treated well in the supply chain, poses a threat as an invasive species, or could make people or other animals sick.
Meanwhile Smith works to inform policymakers to improve regulations that would protect animals, ecosytems, and prospective pet owners as well. She also works with the industry directly.
Perhaps more than anyone else, however, Smith enjoys educating undergraduates, something she’ll have a chance to do more often now that she’s a full tenure-track faculty member.
“For me what’s most exciting here are the undergrads,” she said. “I love teaching them, I love working with them. I love getting to know them. They are awesome.”
Maybe, she said, it’s because she loved being an undergrad so much at the University of New Mexico before continuing on for her Ph.D. at the University of California–Santa Barbara and then postdoctoral work at the University of Georgia.
“I was a really happy undergrad,” she said. “For me that time period of my life was very formative and super-exciting.”
It seems exciting to work with her, too. Last spring, for instance, she involved three enthusiastic students in working on PetWatch. Over the summer she worked with student Michael Goldberg, who wrote programming scripts for her WHO database project. This year she’s mentoring five students as they work on their senior theses.