The arrival and rapid spread of the mosquito-borne viral disease Chikungunya across the Americas is one of the most significant public health developments of recent years, preceding and mirroring the subsequent spread of Zika. Globalization in trade and travel can lead to the importation of these vi...ruses, but climatic conditions strongly affect the efficiency of transmission in local settings. In order to direct preparedness for future outbreaks, it is necessary to anticipate global regions that could become suitable for Chikungunya transmission. Here, we present global correlative niche models for autochthonous Chikungunya transmission. These models were used as the basis for projections under the representative concentration pathway (RCP) 4.5 and 8.5 climate change scenarios. In a further step, hazard maps, which account for population densities, were produced. The baseline models successfully delineate current areas of active Chikungunya transmission. Projections under the RCP 4.5 and 8.5 scenarios suggest the likelihood of expansion of transmission-suitable areas in many parts of the world, including China, sub-Saharan Africa, South America, the United States and continental Europe. The models presented here can be used to inform public health preparedness planning in a highly interconnected world.
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Environmental Research Volume 151, November 2016, Pages 115-123
Dengue is the world’s most important arboviral disease in terms of number of people affected. Over the past 50 years, incidence increased 30-fold: there were approximately 390 million infections in 2010. Globalization, trade, travel,... demographic trends, and warming temperatures are associated with the recent spread of the primary vectors Aedes aegypti and Aedes albopictus and of dengue. Overall, models project that new geographic areas along the fringe of current geographic ranges for Aedes will become environmentally suitable for the mosquito’s lifecycle, and for dengue transmission. Many endemic countries where dengue is likely to spread further have underdeveloped health systems, increasing the substantial challenges of disease prevention and control. Control focuses on management of Aedes, although these efforts have typically had limited effectiveness in preventing outbreaks. New prevention and control efforts are needed to counter the potential consequences of climate change on the geographic range and incidence of dengue, including novel methods of vector control and dengue vaccines.
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Trypanosoma cruzi is the etiological agent of Chagas disease (CD), considered one of the most important parasitic infections in Latin America. Between 25 and 90 million humans are at infection risk via at least one of multiple infection mechanisms. Under natural conditions, the principal transmissio...n modes are transplacental or via one of more than 140 hematophagous triatomine bugs (Reduviidae: Triatominae). Triatomines acquire the parasite from mammal reservoirs due to their obligate blood-feeding (albeit triatomines can also feed on non-reservoir vertebrates such as birds and reptiles). The disease burden for CD in the Latin America and Caribbean region, based on disability-adjusted life-years (DALYs), is at least five times greater than that of malaria, and is approximately one-fifth that of HIV/AIDS. In recent decades, CD has extended to other continents outside natural reservoir or vector distributions due to human migration, with a minimum estimated 10 million individuals infected worldwide.
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Chagas disease (CD) is a neglected tropical disease, endemic in Latin America, but due to migration and environmental changes it has become a global public health issue.
Chagas disease is currently endemic and also predicted to be at increased transmission risk under future climate change scenarios. Similarly, an expansion of areas in the United States at increased risk for Chagas disease transmission is also expected over the next several decades under climate chan...ge scenarios. Of particular interest is the predicted northern shift of triatomine species to central regions of the United States with historically unsuitable climates for T. cruzi vectors. The weight of evidence regarding the influences climate change may pose on T. cruzi vector species distributions demonstrates the sensitivity of Chagas disease transmission to future climate variability. In order to advance forecasts for the impact climate change may have on Chagas disease transmission in the Americas, it is imperative to
further develop, utilize, and perhaps combine predictive species distribution modeling approaches that integrate accurate, long term data on climate variables, vector species distributions, Chagas disease incidence, as well as other socio-ecological variables.
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