Environmental Factor, May 2009, National Institute of Environmental Health Sciences
Colwell Presents 8th Annual Spirit Lecture on Global Health
By Eddy Ball
People from NIEHS and the Triangle scientific community turned out on March 27 to hear distinguished scientific leader and microbiologist Rita Colwell, Ph.D., discuss her life in science and her career-long quest to understand the Vibrio cholerae bacterium. Colwell's talk was sponsored by the NIEHS Diversity Council, which honors women in science each year with the Spirit Lecture, and the NIEHS Frontiers of Environmental Sciences Lecture Series, which has featured several recent talks on the impact of climate change on global health.
NIEHS Biologist Molly Vallant, chair of the Spirit Lecture Committee, opened the program. NIEHS Director Linda Birnbaum, Ph.D., then introduced Colwell (http://www.cbcb.umd.edu/colwell-fellowship) , calling her a "shining light" for women in science. Birnbaum described the speaker as "a woman who has managed to do it all" by successfully combining an outstanding career in microbiology, environmental public health and scientific leadership with a rewarding family life.
In the course of her Spirit Lecture on "Climate, Oceans, Infectious Disease and Human Health: The Saga of Cholera," Colwell engaged her audience with stories of her childhood and anecdotes of her struggles with male domination in science. Colwell, who was once told by her department chairman at Purdue University that "we don't waste fellowships on women," opened the global health portion of her talk with an overview of such climate-change triggered health risks as the spread of malaria into newly warmer and wetter environments and the hantavirus outbreak in the Southwestern U.S. following the 1991-1992 El Niño.
Colwell then related the story of her groundbreaking research into the lifecycle of the cholera bacterium and novel ways for predicting outbreaks. She also described an elegantly simple and inexpensive filtration method to help people in developing nations protect themselves against the preventable misery, disease and death caused by exposure to cholera in their drinking water. According to Colwell, cholera is grossly underreported, causing many more than the hundreds of thousands of cases and many thousands of deaths documented each year by governments and public health organizations.
Vibrio, Colwell explained, is a "home grown" organism present in the waters of virtually every estuary in the world's temperate and tropical regions. The bacterium is responsible, she said, for the majority of deaths among children under five years old in developing countries. She predicted that climate change has the potential to modify the environment in ways that will make outbreaks of bacterial disease even more common and trigger "evolution at a breakneck pace" among vector organisms and their hosts.
Her groundbreaking discoveries of the dormant, non-culturable stage in the lifecycle of cholera and the roles of phytoplankton and zooplankton in cholera outbreaks laid the foundation for research on ways to predict when the conditions are right for outbreaks in specific areas and how intense the outbreaks will be. Colwell continues her work developing a model driven by satellite-remote sensing capable of tracking the spatial and temporal development of plankton plumes, as they emanate from major rivers where cholera is known to be endemic to coastal areas where people can be exposed to large numbers of the bacteria.
Toward the end of her talk, Colwell showcased the results of translational research into preventing cholera infection in Bangladesh by filtering untreated surface water to remove the zooplankton, particularly copepods, that carry V. cholerae. She and her colleagues demonstrated that residents can effectively remove more than 99 percent of V. cholerae cells attached to plankton from their water - using the inexpensive sari cloth that even the poorest women in Bangladesh wear, folded four to eight times, as a filter to capture plankton as small as 20 microns in diameter.
Following her talk, NIEHS Chemist and Chair of the Diversity Council Brad Collins presented Colwell with a certificate of appreciation from NIEHS.