Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate change one factor in malaria spread

04.03.2010
Climate change is one reason malaria is on the rise in some parts of the world, new research finds, but other factors such as migration and land-use changes are likely also at play. The research, published in The Quarterly Review of Biology, aims to sort out contradictions that have emerged as scientists try to understand why malaria has been spreading into highland areas of East Africa, Indonesia, Afghanistan and elsewhere.

"We assessed … conclusions from both sides and found that evidence for a role of climate in the dynamics is robust," write study authors Luis Fernando Chaves from Emory University and Constantianus Koenraadt of Wageningen University in the Netherlands. "However, we also argue that over-emphasizing a role for climate is misleading for setting a research agenda, even one which attempts to understand climate change impacts on emerging malaria patterns."

Malaria, a parasitic disease spread to humans by mosquitoes, is common in warm climates of Africa, South America and South Asia. The development and survival, both of the mosquito and the malaria parasite are highly sensitive to daily and seasonal temperature patterns and the disease has traditionally been rare in the cooler highland areas. Over the last 40 years, however, the disease has been spreading to the highlands, and many studies link the spread to global warming. But that conclusion is far from unanimous. Other studies have found no evidence of warming in highland regions, thus ruling out climate change as a driver for highland malaria.

Chaves and Koenraadt re-examined more than 70 of these studies. They found that the studies ruling out a role for climate change in highland malaria often use inappropriate statistical tools, casting doubt on their conclusions.

For example, an oft-cited 2002 study of the Kericho highlands of western Kenya found no warming trend in the area. But when Chaves and Koenraadt ran the same temperature data from that study through three additional statistical tests, each test indicated a significant warming trend. Similar statistical errors plague other comparable studies, the researchers say.

In contrast, most studies concluding that climate change is indeed playing a role in highland malaria tend to be statistically strong, Chaves and Koenraadt found. But just because climate is one factor influencing malaria's spread does not mean it is the only one. What is needed, the researchers say, is a research approach that combines climate with other possible factors.

"Even if trends in temperature are very small, organisms can amplify such small changes and that could cause an increase parasite transmission," Chaves said. "More biological data will improve our overall understanding of malaria and will allow scientists to propose more general and accurate models on the impacts of climate change on malaria transmission."

The authors cite numerous factors that could interact with climate to influence malaria spread. They point to research showing that people migrating from lowlands may be introducing the malaria parasite into highland regions. Changes in farming practices may also play a role. Irrigation associated with more intensive farming may be creating more places for mosquitoes to breed. Another example comes from two studies that linked malaria increases in the Bure highlands of Ethiopia to increased maize farming. There, the immature and aquatic stages of mosquitoes thrive on a diet of maize pollen, and more mosquitoes can mean more malaria.

"A major future challenge will be to link up what happens with mosquitoes and parasites at the household level with long-term climate change scenarios at the continental scale," Koenraadt said.

The spread of malaria in highlands is of great concern to those who work to contain the disease. But understanding the many factors that influence the spread of highland malaria could help with efforts to control the disease worldwide, Chaves and Koenraadt conclude.

"In the light of global efforts towards malaria elimination, highland areas will be interesting starting points from where control efforts could interrupt transmission and aid in shrinking the world's malaria map." Koenraadt said.

More information about global efforts to control malaria can be found at malariaeliminationgroup.org. Discussions on malaria elimination can be found at malariaworld.org.

Luis Fernando Chaves and Constantianus J M Koenraadt, "Climate change and highland malaria: Fresh air for a hot debate." The Quarterly Review of Biology 85:1 (March 2010).

The premier review journal in biology since 1926, The Quarterly Review of Biology publishes articles in all areas of biology but with a traditional emphasis on evolution, ecology, and organismal biology. QRB is published by the University of Chicago Press.

Kevin Stacey | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Studies and Analyses:

nachricht Amputees can learn to control a robotic arm with their minds
28.11.2017 | University of Chicago Medical Center

nachricht The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>