Early effects of climate change: do they include changes in vector-borne disease?

Abstract

The world's climate appears now to be changing at an unprecedented rate. Shifts in the distribution and behaviour of insect and bird species indicate that biological systems are already responding to this change. It is well established that climate is an important determinant of the spatial and temporal distribution of vectors and pathogens. In theory, a change in climate would be expected to cause changes in the geographical range, seasonality (intra-annual variability), and in the incidence rate (with or without changes in geographical or seasonal patterns). The detection and then attribution of such changes to climate change is an emerging task for scientists. We discuss the evidence required to attribute changes in disease and vectors to the early effects of anthropogenic climate change. The literature to date indicates that there is a lack of strong evidence of the impact of climate change on vector-borne diseases (i.e. malaria, dengue, leishmaniasis, tick-borne diseases). New approaches to monitoring, such as frequent and long-term sampling along transects to monitor the full latitudinal and altitudinal range of specific vector species, are necessary in order to provide convincing direct evidence of climate change effects. There is a need to reassess the appropriate levels of evidence, including dealing with the uncertainties attached to detecting the health impacts of global change.

Risk Factors for the Presence of Chikungunya and Dengue Vectors (Aedes aegypti and Aedes albopictus), Their Altitudinal Distribution and Climatic Determinants of Their Abundance in Central Nepal

“…These human related factors which act as confounders should be integrated in models to predict the future impacts of climate change on DENV vectors and transmission [ 41 , 69 , 79 , 80 ]. The effects of climate and other environmental changes are location-specific and it has been projected that the impact of climate change can alter the geographic distribution of disease vectors and vector-borne diseases [ 81 – 83 ].…”

Mapping Avian Influenza Transmission Risk at the Interface of Domestic Poultry and Wild Birds

“…An increased global demand for meat products has caused rapid intensification of the domestic livestock industry ( 3 ), and improvements to transportation and market chains has brought humans and their agricultural systems closer together ( 4 – 6 ). Coupled with climate change and landscape fragmentation ( 7 – 9 ), incidence of emerging zoonoses is likely to continue to rise, with particular threat in developing regions such as China, India, and parts of Southeast Asia ( 7 – 10 ).…”

Climate Change and Spatiotemporal Distributions of Vector-Borne Diseases in Nepal – A Systematic Synthesis of Literature

“…Although no single factor can fully explain the transmission of VBDs, climate change can alter the geographical distribution of disease vectors and VBDs [ 3 ], for example, by rendering previously endemic areas unsuitable and previously non-endemic areas suitable for their existence and reproduction [ 40 , 41 , 42 ]. As higher latitudes and altitudes are more sensitive to climate change and experiencing higher warming rates [ 2 , 43 , 44 ], a shift of species distributions towards higher elevations has been predicted [ 45 ].…”