Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Looking at Future Dengue Forecast Find Intricate Relationships Between Mosquitoes, Virus and Climate Change

06.07.2012
Dengue fever most likely will become a disease the United States must learn to live with as climate change creates opportunities for the disease to gain a foothold.

But after careful study of the disease’s characteristics, the mosquitoes that carry it and future climate change, two researchers at Texas Tech University said the impact on areas likely to experience dengue won’t necessarily play out along the lines of conventional wisdom.

Their findings were published today (July 5) in Environmental Research Letters.

Many studies have looked at how climate change might alter the geographic range of the mosquito-borne disease and assume the disease will occur wherever mosquitoes that carry it are found. This generally leads to predictions that the disease will move northward as the climate warms

However, Texas Tech researchers dug deeper to study climate constraints on the geographic range of the mosquito that carries dengue and the incubation characteristics of the disease within the mosquito. Factoring these into the equation, they found Southern outbreaks would decrease in size overall and become more common in the spring and fall while Northern areas could experience larger outbreaks throughout the summer.

Of the three cities studied, outbreaks in Chicago during the summer season could be larger than outbreaks in Atlanta and Lubbock, Texas during the spring and fall.

“When we think about climate change, often the first image that comes to mind is the Arctic or a polar bear,” said Katharine Hayhoe, co-author and director of the Climate Science Center at Texas Tech. “But the real reason why we care about climate change is because it’s going to affect what matters to us in the places where we live. And what affects us more than our health? We did this study because climate change can interact with diseases and the vectors that carry these diseases.”

Dengue fever is a viral infection spread by several types of mosquitoes. The disease causes fever, headache and extreme muscle and joint pain, hence its other name – breakbone fever. A rash similar to measles also is common. Originally from Africa, the disease is found in 110 countries worldwide.

The disease occurs mainly in Mexico, Central and Northern South American countries today, though cases have been documented in far South Texas and Florida. Most people infected may feel nothing to cold-like symptoms. The acute form of the disease occurs in 20 percent of people infected. Survivability of the disease is good, with only 1 percent of those receiving treatment dying or 5 percent who are untreated.

As climate change occurs, the Asian tiger mosquito that occurs in areas from Lubbock to Atlanta and on up to Chicago likely will harbor the virus as temperature and rainfall changes make it more hospitable for the virus to survive further north, said Richard Erickson, a doctoral candidate in the Department of Environmental Toxicology at Texas Tech and lead author on the study.

He said researchers used four different climate change models and two different future energy use and population scenarios to project possible outcomes that cover the range of uncertainty in understanding how climate may change in response to human activities in the future.

“Dengue has been described as the most important vector-borne disease in the world because there are up to 100 million infections annually worldwide and up to 40 percent of the world’s population is threatened by the disease,” Erickson said. “Climate change is expected to increase the range of the disease and number of people at risk. Dengue is conventional, though, as a tropic/sub-tropical disease that occurs in the developing world, but in recent years there have been outbreaks in the developed world and locally acquired cases in non-tropical regions, such as France, Croatia and Texas.”

Erickson said most people have studied how climate change affects organisms by examining climate envelopes, which look at current habitats and match them with projected climate conditions. For example, people might expect plant and animal species to shift their range to the north as the earth warms.

However, Erickson and Hayhoe used a mechanistic population model for a mosquito species that did not necessarily assume a simple, broad shift in disease following mosquito populations.

“This approach allows us to better understand how climate change will affect the mosquito species and diseases transmitted by it,” he said. “Surprisingly, we found that dengue would shift, rather than increase the risk for dengue outbreaks within the southern United States. This occurred because projected climate conditions in the South became too warm and decreased the life expectancy of the Asian tiger mosquito. The shortened life span prevented the mosquito from incubating dengue before it died. Under the projected climate change, we found that dengue outbreaks in the South would be more likely to occur during the spring and fall. Additionally, we found that climate will likely increase northern range of dengue risk within the United States.”

Both researchers said that the study shows just one example of how the effects of climate change can often be nonlinear and counter-intuitive and recommended further study into animal and climate systems to understand how climate change will affect them.

Co-authors include Stephen Cox, Erickson’s advisor, adjunct professor at The Institute of Environmental and Human Health (TIEHH) and director of operations at research at Testing Laboratory LLC; Linda Allen Horn Professor of Mathematics; Kevin Long, associate professor of Mathematics; and Steve Presley, associate professor of immunotoxicology and countermeasures to biological and chemical threats at TIEHH.

The research project was funded by a grant from the U.S. Department of Defense.

CONTACT: Katharine Hayhoe, director of the Climate Science Center at Texas Tech University, (806) 742-0015 or katharine.hayhoe@ttu.edu; Richard Erickson, doctoral candidate in the Department of Environmental Toxicology at Texas Tech University, (806) 885-4567 or raerickson@gmail.com.

John Davis | Newswise Science News
Further information:
http://www.ttu.edu

More articles from Health and Medicine:

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

nachricht Highly precise wiring in the Cerebral Cortex
21.09.2017 | Max-Planck-Institut für Hirnforschung

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>