Studying infectious diseases and their causes, sources and spread can help build models to predict their spread, especially when factoring in ongoing climate change challenges.
Potomac Institute Board of Regents member Dr. Rita Colwell spoke about “Climate Change and Human Health: Prospects for the Future.” Using cholera as an exemplar infectious disease, she considers the impact on human health in a world undergoing climate change. Cholera, which is caused by the bacteria Vibrio cholera, is found in many environments throughout the world, which leads to epidemics in areas with poverty, poor sanitation, and unsafe drinking water.
In an effort to understand these epidemics, Dr. Colwell’s research group has made use of satellite imagery and modeling to predict the spread of infectious disease, finding correlations between outbreaks of cholera and chlorophyll on the sea surface, air temperature, and rainfall. In analyzing the evolution of Vibrio cholera, Dr. Collwell notes that the bacteria and other Vibrio human pathogens are extremely similar to bacteria isolated from thermal vents 2500 meters below sea level.
With these novel findings, Dr. Colwell evaluated the recent cholera epidemic in Haiti in January 2010. Even before the earthquake, the record high rainfall and the hot summer were perfect preliminary conditions for the spread of cholera. The earthquake, however, led to a change in river pH, which, in combination with the other conditions, resulted in explosive growth of the bacteria. The case study of cholera in Haiti is an example of the link between climate change and infectious disease. The rise of heavily populated areas coupled with increased flooding and hotter temperatures will result in refugee migration, which can escalate the spread of disease worldwide.
The modeling can also be used to project the spread of other infectious diseases, as seen with Dr. Colwell’s research into Yersinia pestis in Tbilsi, Georgia. Moreover, satellite imagery and modeling can enhance the surveillance and response mechanisms of global health organizations. These advancements, along with further investment in safe drinking water and sanitation, could greatly reduce the spread of disease worldwide.