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.

Mosquitoes and Culicoides biting midges: vector range and the influence of climate change

“…Only 13 years ago, it was concluded that there was no strong evidence to show that climate change was exerting a demonstrable impact on vector-borne diseases, such as malaria, dengue, leishmaniosis and tick-borne diseases (50). In spite of the large amounts of data being gathered, we are still a long way from knowing whether insects and other organisms are responding and adapting to climate change and if such changes apply widely across taxa, space and time (51).…”

Temperature and Population Density Effects on Locomotor Activity of <I>Musca domestica</I> (Diptera: Muscidae)

“…Much theoretical and empirical work has focused on the likely effects of climate warming on disease vectors (Martens et al 1999, Githeko et al 2000, Kovats et al 2001. It has been found that vector-borne pathogens are particularly sensitive to climate warming (Rogers and Randolph 2003).…”

Parasitología veterinaria

“…Aunque el cambio climático puede afectar la distribución y el comportamiento de enfermedades de diversa etiología, se considera que las enfermedades transmitidas por artrópodos -y los vectores mismos-son altamente sensibles a cambios en las condiciones climáticas (Kovats, et al, 2001). El cambio climático puede alterar la relación de un animal con parásitos y vectores.…”

“…Adicionalmente, Kovats, et al (2001) presentan como requerimientos mínimos para aceptar una relación causal entre el cambio climático y los cambios en salud, los siguientes:…”