• PROJECTED IMPACTS OF CLIMATE CHANGE ON ENVIRONMENTAL SUITABILITY FOR MALARIA TRANSMISSION IN WEST AFRICA

Environ Health Perspect; DOI:10.1289/ehp.1206174

Teresa K. Yamana and Elfatih A.B. Eltahir

Author Affiliations open

Ralph M. Parsons Laboratory, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA

Abstract below; full text is at http://ehp.niehs.nih.gov/1206174/

Background: Climate change is expected to affect the distribution of environmental suitability for malaria transmission by altering temperature and rainfall patterns; however, the local and global impacts of climate change on malaria transmission are uncertain.

Objective: We assessed the effect of climate change on malaria transmission in West Africa.

Methods: We coupled a detailed mechanistic hydrology and entomology model with climate projections from general circulation models (GCMs) to predict changes in vectorial capacity, an indication of the risk of human malaria infections, resulting from changes in the availability of mosquito breeding sites and temperature-dependent development rates. Because there is strong disagreement in climate predictions from different GCMs, we focused on the GCM projections that produced the best and worst conditions for malaria transmission in each zone of the study area.

Results: Simulation-based estimates suggest that in the desert fringes of the Sahara, vectorial capacity would increase under the worst-case scenario, but not enough to sustain transmission. In the transitional zone of the Sahel, climate change is predicted to decrease vectorial capacity. In the wetter regions to the south, our estimates suggest an increase in vectorial capacity under all scenarios. However, because malaria is already highly endemic among human populations in these regions, we expect that changes in malaria incidence would be small.

Conclusion: Our findings highlight the importance of rainfall in shaping the impact of climate change on malaria transmission in future climates. Even under the GCM predictions most conducive to malaria transmission, we do not expect to see a significant increase in malaria prevalence in this region.

Citation: Yamana TK, Eltahir EA. 2013. Projected impacts of climate change on environmental suitability for malaria transmission in West Africa. Environ Health Perspect 121:1179–1186; http://dx.doi.org/10.1289/ehp.1206174

Address correspondence to T.K. Yamana, 77 Massachusetts Ave., Room 48-216, Cambridge, MA 02139 USA. Telephone: (617) 253-6596. E-mail: tkcy@mit.edu

This work was funded by the U.S. National Science Foundation (grant EAR-0946280).

The authors declare they have no actual or potential competing financial interests.

Received: 23 October 2012
Accepted: 11 July 2013
Advance Publication: 16 September 2013
Final Publication: 1 October 2013