Social exclusion modifies climate and deforestation impacts on a vector-borne disease

• Published in: PLoS neglected tropical diseases Vol. 2; no. 1; p. e176
• Main Authors: Chaves, Luis Fernando, Cohen, Justin M, Pascual, Mercedes, Wilson, Mark L
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06-02-2008; Public Library of Science (PLoS)
• Subjects: Animals; Biodiversity; Climate; Communicable Diseases - epidemiology; Conservation of Natural Resources; Costa Rica - epidemiology; Disease; Disease Vectors; Ecology/Community Ecology and Biodiversity; Ecology/Conservation and Restoration Ecology; Ecology/Spatial and Landscape Ecology; Ecology/Theoretical Ecology; Forests; Humans; Infections; Infectious Diseases/Epidemiology and Control of Infectious Diseases; Infectious Diseases/Neglected Tropical Diseases; Infectious Diseases/Protozoal Infections; Infectious Diseases/Tropical and Travel-Associated Diseases; Leishmaniasis, Cutaneous - epidemiology; Principal components analysis; Public Health and Epidemiology/Environmental Health; Public Health and Epidemiology/Global Health; Public Health and Epidemiology/Infectious Diseases; Public Health and Epidemiology/Social and Behavioral Determinants of Health; Sand & gravel; Social Environment; Statistical methods; Studies; Tropical diseases; Costa Rica
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0000176

The emergence of American Cutaneous Leishmaniasis (ACL) has been associated with changes in the relationship between people and forests, leading to the view that forest ecosystems increase infection risk and subsequent proposal that deforestation could reduce re-emergence of this disease.
We analyzed county-level incidence rates of ACL in Costa Rica (1996-2000) as a function of social and environmental variables relevant to transmission ecology with statistical models that incorporate breakpoints. Once social marginality was taken into account, the effect of living close to a forest on infection risk was small, and diminished exponentially above a breakpoint. Forest cover was associated with the modulation of temporal effects of El Niño Southern Oscillation (ENSO) at small spatial scales, revealing an additional complex interplay of environmental forces and disease patterns.
Social factors, which previously have not been evaluated rigorously together with environmental and climatic factors, appear to play a critical role that may ultimately determine disease risk.