March of the pathogens: Parasite metabolism can foretell disease ranges under climate change

Morgan Kelly in News at Princeton: Knowing the temperatures that viruses, bacteria, worms and all other parasites need to grow and survive could help determine the future range of infectious diseases under climate change, according to new research.

Princeton University researchers developed a model that can identify the prospects for nearly any disease-causing parasite as the Earth grows warmer, even if little is known about the organism. Their method calculates how the projected temperature change for an area would alter the creature's metabolism and life cycle, the researchers report in the journal Ecology Letters.

Lead author Péter Molnár, a Princeton postdoctoral researcher of ecology and evolutionary biology, explained that the technique is an all-inclusive complement to current methods of predicting how climate change will affect disease, which call for a detailed knowledge of the environmental factors a specific parasite needs to thrive. But for many parasites, that information doesn't exist.

The more general Princeton model is based on the metabolic theory of ecology. Under this premise, all biological organisms need a balance between body size and body temperature to maintain the metabolism that keeps their organs functioning. Like any cold-blooded creature, disease-causing parasites rely on external temperatures for this balance. Scientists with knowledge of a parasite's body size and life cycle could use the Princeton metabolic model to predict how the organism would fare in altered climates.

"Our framework is applicable to pretty much any parasite, and utilizes established metabolic patterns shown to hold across a wide variety of species," Molnár said. "It would be impossible to ever gather enough data to develop a separate climate-change model for each existing and emerging disease in humans, wildlife and livestock," Molnár said. "With our physiological approach, many of the parameters for a specific pathogen can be predicted based on what is known about metabolic processes in all parasites, so that the model remains applicable to new and less-studied species as well."...

A cameo by the Marburg virus, image from the CDC