Climate change impacts and vulnerability in Europe 2016

Climate change impacts on society
(Petersen et al., 2013). Since 2010, there have been
annual outbreaks in south‐eastern and eastern Europe,
suggesting an endemic transmission cycle and thus
a resurgent public health problem (Map 5.5) (Paz
and Semenza, 2013; Semenza et al., 2016). Positive
temperature anomalies from the monthly averages
were the most important determinants of the 2010 WNV
outbreak (Paz et al., 2013). Over the subsequent years,
other environmental drivers (besides temperature)
were also identified as important, such as the state
of vegetation, water bodies (modified normalised
difference water index) and bird migratory routes (Tran
et al., 2014; Marcantonio et al., 2015).
Past trends: sandfly-borne diseases
Leishmaniasis is the most common disease transmitted
by phlebotomine sandflies in Europe. The transmission
of the two parasites responsible for this disease that
are endemic in the EU (Leishmania infantum, causing
visceral leishmaniasis, and Leishmania tropica, causing
cutaneous leishmaniasis) is heavily influenced by
temperature. Leishmania tropica occurs sporadically in
Greece and neighbouring countries, while Leishmania
infantum is endemic in the Mediterranean region of the
EU. Sandfly vectors currently have wider distribution
ranges than the parasites. The evidence for an impact
of climate change on the distribution of the sandfly in
Europe is scarce (Ready, 2010). Climate change was
suggested as one possible reason for the observed
northwards expansion of sandfly vectors in Italy (Maroli
et al., 2008). The contemporary risk for central Europe
has been estimated to be low owing to temperature
constraints on pathogen growth (Fischer et al., 2010).
Projections: tick-borne diseases
Cold temperatures appear to determine the altitudinal
and latitudinal limits of Ixodes ricinus (Ostfeld and
Brunner, 2015). Thus, an expansion of the distribution
range of ticks to higher altitudes and latitudes is
projected, as milder winter temperatures, longer
vegetation seasons and earlier onsets of summer
appear and warmer temperatures occur, under the
condition that their natural hosts (deer) would also shift
their distribution (Jaenson and Lindgren, 2011). One
Map 5.5
Current distribution of West Nile virus infections in Europe
-30°
-20°
-10°
0°
10°
20°
30°
40°
50°
60°
70°
Distribution of West Nile
virus infections in Europe
One or more
reported cases
Outside coverage
60°
50°
50°
40°
40°
0 500 1000 1500 km
0°
10°
20°
30°
40°
Note: The map shows districts with probable and confirmed cases of West Nile virus infections, as of 20 November 2014.
Source: Adapted from Semenza et al., 2016.
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