1. TALA Research Group, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
2. Kenya Medical Research Institute/Wellcome Trust Collaborative Programme, PO Box 43640, Nairobi, Kenya
3. Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
4. Oxford Tick Research Group, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
5. Centre for Resource and Environmental Studies, The Australian National University, Canberra ACT 0200, Australia
6. US Army Medical Research Unit – Kenya, Box 30137, Nairobi, Kenya
7. Decision Systems Technologies, Inc. (DSTI), 1700 Research Boulevard, Suite 200, Rockville, Maryland 200850, USA
8. Centre for Tropical Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK

Correspondence to: Simon I. Hay^1,2 Correspondence and requests for materials should be addressed to S.I.H. (e-mail: Email: simon.hay@zoo.ox.ac.uk).

Abstract

The public health and economic consequences of Plasmodium falciparum malaria are once again regarded as priorities for global development. There has been much speculation on whether anthropogenic climate change is exacerbating the malaria problem, especially in areas of high altitude where P. falciparum transmission is limited by low temperature^{1, 2, 3, 4}. The International Panel on Climate Change has concluded that there is likely to be a net extension in the distribution of malaria and an increase in incidence within this range⁵. We investigated long-term meteorological trends in four high-altitude sites in East Africa, where increases in malaria have been reported in the past two decades. Here we show that temperature, rainfall, vapour pressure and the number of months suitable for P. falciparum transmission have not changed significantly during the past century or during the period of reported malaria resurgence. A high degree of temporal and spatial variation in the climate of East Africa suggests further that claimed associations between local malaria resurgences and regional changes in climate are overly simplistic.