The research, conducted by the Malaria Atlas Project (MAP), a multinational team of researchers funded mainly by the Wellcome Trust, suggests that current interventions could have a far more dramatic – and positive – effect on reducing the spread of malaria than any negative effects caused by climate change.
A steady stream of modelling studies has predicted that malaria will worsen and its range will spread as the world gets warmer. Malaria already kills more than a million people each year, mainly young children and pregnant women, with some 2.4 billion people at risk from its most deadly form.
Last year the Malaria Atlas Project produced a new map of modern-day malaria risk, giving researchers a unique opportunity to examine the effects that climate change may have had on the disease.
The new research compared this modern-day map with a historic reconstruction of malaria at its assumed peak, around 1900, and measured changes in the disease risk since that time. Although it is widely known that malaria has receded from many areas where it was previously endemic, such as the USA and much of Europe, the researchers were able to measure for the first time the extent of this recession and show that even in tropical areas the intensity of transmission has declined substantially in the last century.
The research was led by Dr Pete Gething from the Department of Zoology at the University of Oxford. He says: “The recession in malaria since 1900 is of little comfort to the billions of people still at serious risk, but it is important when thinking about the effects of climate on the future of the disease. We know that warming can boost malaria transmission but the major declines we’ve measured have happened during a century of rising temperatures, so clearly a changing climate doesn’t tell the whole story.”
The team compared the increases in malaria predicted by global warming scenarios with the actual declines of the 20th century. Importantly, they also gauged the efficacy of different disease control measures when set against the possible adverse effects of rising temperatures and concluded that interventions such as insecticide-treated bed nets or modern anti-malarial drugs can potentially outweigh the effects of global warming as much as tenfold.
Dr Simon Hay, who leads the MAP group in Oxford, explains: “When we looked at studies measuring the possible impact of bed nets or drugs, it was clear that they could massively reduce transmission and counteract the much smaller effects of rising temperatures.
“Malaria remains a huge public health problem and the international community has an unprecedented opportunity to relieve this burden with existing interventions. Any failure in meeting this challenge will be very difficult to attribute to climate change.”
Image: A child sits in a mosquito net, Kenya. Credit: Thomas Omondi/Department for International Development on Flickr
Gething PW et al. Climate change and the global malaria recession. Nature 2010;465(7296):342-5.
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Notes for editors
The Malaria Atlas Project (MAP) is funded by the Wellcome Trust (UK) to assemble medical intelligence and survey data to provide evidence-based maps on the distribution of malaria risk, human population, disease burdens, mosquito vectors, inherited blood disorders and malaria financing and control worldwide. The maps generated are the results of collaboration between malaria scientists in the UK, Kenya, Vietnam, Indonesia, Ecuador and the USA. MAP work in the Asia-Pacific region has been additionally supported by a grant from the Li Ka Shing Foundation.
The Wellcome Trust is a global charity dedicated to achieving extraordinary improvements in human and animal health. It supports the brightest minds in biomedical research and the medical humanities. The Trust’s breadth of support includes public engagement, education and the application of research to improve health. It is independent of both political and commercial interests.
The Department of Zoology, within the Mathematical, Physical and Life Sciences Division at the University of Oxford, has a long-standing reputation for world-class research and teaching. Research in the department is organised into several research themes; these span a broad spectrum of biology ranging from ecology and behaviour, through to molecular evolution, development and infectious disease biology.
The Kenya Medical Research Institute (KEMRI) is a Kenya government parastatal with the responsibility for health research to improve the health of Kenyans. It is one of the most well developed national research institutes in Africa with a network of centres across Kenya such as the Centre of Geographic Medicine Research Coast (CGMR-C) that is home to the KEMRI-Wellcome Trust Research Programme. The programme formally established in 1989, is a partnership between KEMRI, the University of Oxford and the Wellcome Trust. It conducts basic, epidemiological and clinical research in parallel, with results feeding directly into local and international health policy, and aims to expand the country’s capacity to conduct multidisciplinary research that is strong, sustainable and internationally competitive.
The University of Florida (UF), USA, is a major, public, comprehensive, land grant, research university. The state’s oldest and most comprehensive university, UF is among the USA’s most academically diverse public universities. UF has a long history of established programs in international education, research and service.
The Emerging Pathogens Institute at the University of Florida, USA, was opened in 2010 and aims to fuse key disciplines to develop outreach, education, and research capabilities designed to prevent or contain new and re-emerging diseases.