Navigation Links
Ecologists question effects of climate change on infectious diseases

Recent research has predicted that climate change may expand the scope of human infectious diseases. A new review, however, argues that climate change may have a negligible effect on pathogens or even reduce their ranges. The paper has sparked debate in the ecological community.

In a forum in the April issue of Ecology, Kevin Lafferty of the U.S. Geological Survey's Western Ecological Research Center suggests that instead of a net expansion in the global range of diseases, climate change may cause poleward range shifts in the areas suitable for diseases as higher latitudes become warmer and regions near the equator become too hot.

The newly suitable areas for diseases will tend to be in more affluent regions where medicines are in widespread use and can more readily combat the diseases, Lafferty says. He cites model estimations that the most dangerous kind of malaria will gain 23 million human hosts outside of its current range by the year 2050, but will lose 25 million in its current range.

"The dramatic contraction of malaria during a century of warming suggests that economic forces might be just as important as climate in determining pathogen ranges," Lafferty says.

Mercedes Pascual of the University of Michigan sees the situation very differently. Pascual is the lead author of one of five Forum papers published in response to Lafferty. Although she agrees that disease expansion in some areas could be accompanied by retraction in others, she emphasizes that disease range does not always correlate with the number of humans infected. In regions of Africa and South America, for example, humans have historically settled in high latitudes and altitudes. If climate change makes these areas more fit for mosquito breeding and for pathogen development, she writes, then a number of infections could expand. She notes that scientists are already seeing evidence of this pattern.

"It would be very unfortunate if the conclusions in Lafferty's paper were taken as evidence that climate change does not matter to infectious diseases," Pascual says. "Range shifts will matter and should be better understood."

Lafferty agrees that range shifts mean there will be winners and losers among human populations. Knowing how disease ranges will shift, instead of assuming a global expansion of diseases, will be the key to distributing resources effectively, he says.

Scientists have used the fact that infectious diseases are most prevalent in the tropics to argue that warmer, wetter conditions that might occur under climate change would lead to an increase in infectious disease transmission. However, Lafferty points out that climate change isn't making the whole world warmer and wetter: Warming trends over the last 60 years have led instead to an increase in hot, dry, desert-like climates. Further, he says, infectious diseases don't all increase during warm, wet weather. Meningitis peaks during the tropical dry season, for example, and influenza is an obvious staple of winter weather in temperate climes.

Pascual argues, however, that humans have a history of altering the landscape to suit their needs and thus might unintentionally create better habitat for disease carriers. For example, humans seldom leave accessible arid areas alone; instead, they irrigate them for use as farmlands. According to Pascual, the creation of water sources could provide havens for mosquitoes, and thus malaria parasites, to remain in areas that would otherwise dry out.

"We live in a world in which urban and rural areas are increasingly interfacing with each other," says Pascual. "This underscores the challenges for predicting the Earth's changing environment."

Lafferty agrees that climate isn't the only issue that affects disease ecology, and maintains that climate may play only a small part in determining disease ranges.

"If we over-emphasize the role of climate, which we have little control over, at the expense of other factors that drive disease dynamics, we may be missing the forest for the trees," he says.


Contact: Christine Buckley
Ecological Society of America

Related biology news :

1. Ecologists report quantifiable measures of natures services to humans
2. Ecologists use oceanographic data to predict future climate change
3. Ecologists say metabolism accounts for why natural selection favors only some species
4. Studies of small water fleas help ecologists understand population dynamics
5. Biofuels and biodiversity dont mix, ecologists warn
6. Ecologists tease out private lives of plants and their pollinators
7. Ecologists, material scientists pursue genetics of diatoms elegant, etched casing
8. Ecologists discover city is uber-forest for big owls
9. Mountain on Mars may answer big question
10. New models question old assumptions about how many molecules it takes to control cell division
11. Similar survival rates for Pacific salmon in Fraser, Columbia Rivers raises new questions
Post Your Comments:
(Date:5/16/2016)...   EyeLock LLC , a market leader of ... an IoT Center of Excellence in Austin, ... of embedded iris biometric applications. EyeLock,s iris ... security with unmatched biometric accuracy, making it the most ... EyeLock,s platform uses video technology to deliver a fast ...
(Date:4/28/2016)... BANGALORE, India , April 28, 2016 /PRNewswire/ ... product subsidiary of Infosys (NYSE: INFY ), and ... global partnership that will provide end customers with ... banking and payment services.      (Logo: ... area for financial services, but it also plays a fundamental ...
(Date:4/19/2016)... DUBAI , UAE, April 20, 2016 ... can be implemented as a compact web-based "all-in-one" system ... in the biometric fingerprint reader or the door interface ... requirements of modern access control systems. The minimal dimensions ... the ID readers into the building installations offer considerable ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Apellis Pharmaceuticals, Inc. today announced positive ... its complement C3 inhibitor, APL-2. The trials were ... studies designed to assess the safety, tolerability, pharmacokinetics ... healthy adult volunteers. Forty subjects were ... dose (ranging from 45 to 1,440mg) or repeated ...
(Date:6/23/2016)... , June 23, 2016 ... Hematology Review, 2016;12(1):22-8 ... , the peer-reviewed journal from touchONCOLOGY, Andrew ... escalating cost of cancer care is placing an ... result of expensive biologic therapies. With the patents ...
(Date:6/23/2016)... San Francisco, CA (PRWEB) , ... June 23, ... ... capture (EDC) software, is exhibiting at the Pennsylvania Convention Center and will showcase ... DIA Annual conference. ClinCapture will also be presenting a scientific poster on Disrupting ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... a new line of intelligent tools designed, tuned and optimized exclusively for Okuma ... 12–17 in Chicago. The result of a collaboration among several companies with expertise ...
Breaking Biology Technology: