Temperature-derived potential for the establishment of phlebotomine sandflies and visceral leishmaniasis in Germany

Abstract

Abstract. Climate change is expected to manifest in the shift of organisms to regions where they were not present in the past, potentially entailing previously unseen biological risks. However, studies evaluating these future trends are scarce. Here, an important group of vectors (sandflies) and the pathogen transmitted (Leishmania infantum complex) causing the infectious disease visceral leishmaniasis is investigated, focussing on potential establishment in Germany during the 21 st century. As the most important habitat factor, temperature requirements of pathogen and vector were derived from the literature and compared with recent climate records -provided by worldclim -and climate change scenarios. Climate data from the Regional Climate Model REMO were obtained and averaged over the time periods 2011-2040, 2041-2070 and 2071-2100. Projected temperature changes (based on the A1B and A2 scenarios) were correlated with the constraints of vector and pathogen. Simulated potentially suitable habitat areas for vector and pathogen were merged to generate a temperature-derived risk map of visceral leishmaniasis. Temperature conditions seem to become suitable for the vector across large swaths of Germany. Nevertheless, temperature constraints for the pathogen may defer the establishment of the parasitic disease, particularly during the first half of the 21 st century. Long-lasting epidemics of visceral leishmaniasis are therefore not expected in Germany during the next few decades, although during extremely warm years an increase in autochthonous cases of leishmaniasis may occur. The southwest (Upper Rhine Valley) and west (Cologne Bight) of Germany are identified as risk areas. The time of potential establishment and corresponding rise in biological risk varies between scenarios, due to differences in the predicted rate of temperature increase.

Risk map for cutaneous leishmaniasis in Ethiopia based on environmental factors as revealed by geographical information systems and statistics

“…The observation of CL cases as high as 2,700 m above MSL and inclusion of areas above this altitude as high risk by the model requires further investigation. This could probably reflect a change in vector behaviour and ecology, possibly related to global warming leading to sand flies seeking higher altitudes as suggested by Aspock et al (2008) and others (Dereure et al, 2009;Fischer et al, 2010). We also found rainfall to be a predictor, a result supported by Ashford (1977), who documented that human cases of CL occur in areas with rainfall amounts above 800 mm.…”

Epidemiological aspects and spatial distribution of human and canine visceral leishmaniasis in an endemic area in northeastern Brazil

“…Climatic factors such as temperature, humidity and rainfall, also influences the sand flies population variance (Bhunia et al, 2010;Fischer et al, 2010). The large adaptability of L. longipalpis in urban environments, both inside and outside the home, and at different temperatures has influenced the dynamics of transmission of VL (Oliveira et al, 2008.…”

Kapitel 6: Der Einfluss des Klimawandels auf die Anthroposphäre

“…haben sich bereits ausgebreitet . Dazu benötigen die Sandmücken eine Monatsdurchschnittstemperatur in den Sommermonaten von zumindest 20 °C (Fischer et al, 2010).…”