Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Earth Science News .




EPIDEMICS
Projected climate change in West Africa not likely to worsen malaria situation
by Denise Brehm for MIT News
Cambridge MA (SPX) Sep 22, 2013


MIT Professor Elfatih Eltahir and Teresa Yamana combined a new model of malaria transmission with global forecasts for temperature and rainfall to improve projections of malaria infection with climate change. Credit: James M. Long, MIT.

As public-health officials continue to fight malaria in sub-Saharan Africa, researchers are trying to predict how climate change will impact the disease, which infected an estimated 219 million people in 2010 and is the fifth leading cause of death worldwide among children under age 5.

But projections of future malaria infection have been hampered by wide variation in rainfall predictions for the region and lack of a malaria-transmission model that adequately describes the effects of local rainfall on mosquitoes, which breed and mature in ephemeral pools that form during and after monsoons in West Africa.

A new MIT study led by Elfatih Eltahir, a professor in the Department of Civil and Environmental Engineering, combines a new model of malaria transmission with global forecasts for temperature and rainfall to improve predictions of malaria with climate change.

Eltahir and graduate student Teresa Yamana found that although the capacity for malaria transmission will change in some areas of West Africa, overall infection rates are not likely to increase: Climate change by itself is not likely to make the situation worse. A paper on the study appeared online Sept. 16 in the journal Environmental Health Perspectives.

"Malaria is one of the world's leading public-health problems, taking a toll not only in lives, but also in economic terms, especially in Africa," Eltahir says.

"While other researchers are looking at the global impacts of climate change on broadly defined variables such as global temperature or global sea level, the biggest challenge faced by the global climate-change research community is how to come up with credible predictions for specific variables that are relevant to society, such as malaria incidence, defined at the appropriate regional and local scales."

The study used a combined epidemiological and hydrological model of malaria transmission developed earlier by Eltahir and former graduate student Arne Bomblies, now an assistant professor at the University of Vermont. The model uses detailed information about rainfall, temperature, wind, topography and soils at the village scale.

It simulates mosquito behavior by tracking the location, biting, infective status and reproduction cycle of individual female mosquitoes on an hourly basis and includes variables describing humans and other animals that serve as sources of blood meals for mosquitos.

Eltahir and Bomblies tested the model using extensive field data gathered from representative villages in Niger over two years, including adult mosquito abundance, observations of pools, and meteorological and soil-moisture measurements.

To incorporate regional data into the model, Yamana took daily satellite data and broke it down into hourly increments so the model could use hourly rainfall to simulate formation of breeding pools. She established baseline current climate conditions by feeding the model satellite data for five climate zones - starting at the southern fringes of the Sahara and moving south through the Sahel transitional zone into the wetter regions of the Guinean coast.

She then repeated the simulations using long-term temperature and rainfall predictions taken from global climate models, which predict a temperature increase in West Africa from 2 to 6 degrees Celsius by the end of the century, and rainfall changes ranging from large reductions to moderate or large increases.

Working on the assumption that future rainfall levels will fall somewhere in between, Yamana and Eltahir identified the rainfall and temperature changes that would create the best and worst environmental suitability for malaria in each of the five zones.

They found that on the southern border of the Sahara, temperatures will become too hot for the survival of Anopheles funestus and Anopheles gambiae sensu lato, the most common malaria-carrying species in Africa. As a result, any likely changes in rainfall would have only a minor impact on malaria.

On the other extreme, hotter temperatures in the southern zone close to the Guinean coast will speed the development of the malaria parasite, improving environmental suitability for malaria regardless of changes in rainfall. However, this area is already heavily saturated with the disease, so the impact is expected to be minimal unless this region experiences an influx of people from the north.

Between these two extremes, the opposing impacts of warming temperature and increasing rainfall are likely to cancel each other, minimizing the impact on disease transmission along the transitional Sahel zone.

The researchers point out that their study does not take into account possible changes in population, migration, economics, health care and other socioeconomic factors.

"Many countries in this region are very underdeveloped and people are much more vulnerable to changes in the environment than people in more developed areas," Yamana says. "If these countries become fully developed and are no longer vulnerable to vector-borne diseases, or malaria is completely eradicated, that would be fantastic news. But I don't think we can count on either of these things happening in the near future."

.


Related Links
Massachusetts Institute of Technology
Epidemics on Earth - Bird Flu, HIV/AIDS, Ebola






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EPIDEMICS
AIDS epidemic's end by 2030 seen: UN official
Panama City (AFP) Sept 19, 2013
A top UN official said the global AIDS epidemic could be over by 2030 because of progress made in treatment and control of the disease. "I think that 2030 is a viable target to say that we have reached the end of the epidemic," said Luis Loures, a deputy executive director of UNAIDS, the UN agency leading the fight against HIV/AIDS. "HIV will continue existing as a case here or there but ... read more


EPIDEMICS
Australians should be told of boat turn-backs, ex-navy chief

Obama: Navy Yard shooting must inspire gun law change

In Mexico, storms dredge up human errors

Fukushima town protests Abe's global promise on crippled plant: reports

EPIDEMICS
Environmentally friendly cement is stronger than ordinary cement

X-ray science taps bug biology to design better materials and reduce pollution

Catalysts team up with textiles

Raytheon, Falck Schmidt unveil remotely operated long-range surveillance system

EPIDEMICS
Malaysian natives protest as dam begins to fill

Antibacterial products fuel resistant bacteria in streams and rivers

U of M researchers discover early-warning system to prevent fishery collapse

Online citizen scientists: Classify plankton images

EPIDEMICS
Russia mulls piracy charge against Greenpeace protesters

Trail of melting Swiss glacier shows climate change in action

Research: Australian Aboriginals showed adaptability in last ice age

Unprecedented rate and scale of ocean acidification found in the Arctic

EPIDEMICS
Brazil rancher's conviction upheld in US nun's death

Vaccinating cattle against E. coli O157 could cut human cases of infection by 85 percent

Sensors allow for efficient irrigation, give growers more control over plant growth

Different forage affects beef cattle weight, taste

EPIDEMICS
More than 100 killed in Mexico landslides, flooding: official

Mexico looks to rebuild from deadly, costly twin storms

Flight chaos as typhoon lashes southern China, killing three

25 dead as typhoon hits China, flight chaos in Hong Kong

EPIDEMICS
160 UN peacekeepers desert Mali posts: military

Three Ivorian police killed in attacks

Uganda suspends 24 officers over Somalia corruption

Mali ministers met by hail of stones in Tuareg stronghold

EPIDEMICS
Findings in Middle East suggest early human routes into Europe

Paleorivers across Sahara may have supported ancient human migration routes

Orangutans plan their future route and communicate it to others

New evidence that orangutans and gorillas can match images based on biological categories




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement