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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Imported Fire Ant and Household Insects Research » Research » Publications at this Location » Publication #81628
Title: POTENTIAL DENGUE FEVER RISK PROJECTED BY GENERAL CIRCULATION MODELS OF GLOBAL CLIMATE CHANGE

Author
item PATZ, JONATHAN - JOHN HOPKINS-MICROBIOLOGY
item MARTENS, W.J.M. - MAASTRICHT UNIVERSITY
item Focks, Dana
item JETTEN, THEO - WAGENINGEN AGRI. UNIV.

Submitted to: Journal of the American Medical Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/14/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Many if not most scientists who study the world's climate believe that global temperatures will rise between 1.0 and 3.5 degrees celsius (about 2 to 6 degrees Fahrenheit during the next century. Concern has been expressed that warming will adversely affect agriculture and probably result in rising ocean levels permanently flooding coastal areas around the eworld. More recently, however, groups like the Intergovernmental Panel on Climate Change (IPCC) and the World Health Organization (WHO) have concluded that the most serious health consequence will be an increase in diseases transmitted between people by the bite of insects, diseases like malaria, encephalitis, and yellow fever. Using mathematics and computers, scientists from the USDA-ARS Center for Medical, Agricultural and Veterinary Entomology, the Netherlands, and Johns Hopkins University have recently shown that the most important viral disease transmitted by mosquitoes, dengue hemorrhagic fever, currently found throughout the tropics, will be significantly influenced by the expected climate warming. An important conclusion of these studies was that the geographical range of dengue will expand out of the tropics and into temperate areas. Dengue is also expected to move into high-altitude cities such as Mexico City where it is currently too cool to allow transmission. The final conclusion was that a serious form of dengue involving shock and hemorrhage in children will become much more common in the tropics and sub-tropics.

Technical Abstract: This paper quantifies the expected impact of anthropogenically induced climate change on the intensity and distribution of dengue transmission throughout the world. The method uses an expression developed at the USDA-ARS Center for Medical, Agricultural and Veterinary Entomology that describes vectorial capacity modified to reflect the role of temperature on development and survival of the vector and virus. The traditional vectorial capacity expression was used to derive an estimator of the number of adult female mosquito vectors required to just maintain the virus in an endemic state. In this expression, temperature influences adult survival, the lengths of the gonotrophic cycle and the extrinsic incubation period of the virus in the vector, and vector size. The present study on the transmission potential of dengue is based on computer simulation models using weather projections from three different General Circulation Models (GCM). These models indicate an average global elevation of 1.16C by the year 2050. All 3 GCM climate projections when applied to dengue epidemic potential showed: 1) enhanced risk of seasonal transmission; 2) increased risk globally, the largest area change occurring in temperate regions; and 3) in regions already at risk from transmission, epidemic potential rose on aggregate between 31% and 47%. In conclusion, climate change will increase dengue incidence with the first occurrence in regions bordering endemic zones in latitude or altitude. Endemic locations may be at higher risk from hemorrhagic dengue if transmission intensity increases.