74
Japanese encephalitis, dengue, chikungunya, lymphatic filariasis and visceral leishmaniasis towards a cooler mountainous region has been reported from Nepal
(Dhimal et al. 2014a, 2015; Ostyn et al. 2015). Altitude is often used as a proxy for
temperature changes, so one may speculate that this trend might also be true for
more northern/temperate regions.
In Europe, four exotic Aedes types of mosquitoes are currently found (partly
reviewed in Medlock et al. 2012): the Asian tiger mosquito (Ae. albopictus; Adhami
and Reiter 1998), the yellow-fever mosquito (Ae. aegypti; Goncalves et al. 2008),
the Asian bush mosquito (Ae. japonicus japonicus; Schaffner et al. 2009) and Ae.
koreicus (Versteirt et al. 2012). Particularly, the Asian tiger mosquito Ae. albopictus
with widespread European distribution is a competent vector for several VBDs and
therefore poses human public health risks. It is suspected that the Asian tiger mosquito was the main vector for dengue viruses in France in 2015 (Succo et al. 2016)
and for chikungunya virus in Italy in 2007 and 2017 (Rezza 2018) (autochthonous
cases in Europe 2007–2012 reviewed in Tomasello and Schlagenhauf 2013). These
cases show how human transport activities and temperature change facilitate the
establishment of vector species and highlight the importance of actively preventing
such establishments (Eritja et al. 2017; Ducheyne et al. 2018, Reuss et al. 2018,
Dhimal et al. 2018).
Despite temperature, climate change will lead to hydrological changes. For Ae.
albopictus in Europe, it is projected that Mediterranean locations will become more
unsuitable habitats due to climatic variables and changed water regimes, while suitability is increased in middle and northern Europe up to 55°N (Fischer et al. 2014).
Climate and photoperiod also alter the host-seeking and feeding activity in ticks as
well as the seasonal occurrence of vector stages (Altizer et al. 2013; Kurtenbach
et al. 2006).
4.2.3 Distributional Changes of Ticks in Europe
There are objective grounds that climate change influences the distribution and seasonal activity of disease-transmitting ticks (Ogden et al. 2014). The tick Ixodes ricinus is medically highly relevant as a vector for spirochaete bacteria Borrelia
burgdorferi, with Lyme disease extending its distribution northwards in Europe, in
a warmer climate (Lindgren et al. 2000). The taiga tick (Ixodes persulcatus), transmitting the ‘early summer’ meningo-enzephalitis virus, is currently spread from
Russia west-northwards to Scandinavia (Jaenson et al. 2016). Ticks of the genera
Dermacentor with a previously Mediterranean distribution, for instance the Coxiella
burnetti-transmitting sheep tick Dermacentor marginatus (Q fever,) are now established in cold-temperate Germany (Földvári et al. 2016). The Mediterranean tick
Hyalomma marginatum is the main vector for the emerging pathogen CrimeanCongo Hemorrhagic Fever in Europe. International livestock trading guarantees the
tick’s mobility, as ticks live on domestic animals, while the degradation of agricultural land favours the mass development of Hyalomma marginatum (Estrada-Pena
R. Müller et al.
Japanese encephalitis, dengue, chikungunya, lymphatic filariasis and visceral leishmaniasis towards a cooler mountainous region has been reported from Nepal
(Dhimal et al. 2014a, 2015; Ostyn et al. 2015). Altitude is often used as a proxy for
temperature changes, so one may speculate that this trend might also be true for
more northern/temperate regions.
In Europe, four exotic Aedes types of mosquitoes are currently found (partly
reviewed in Medlock et al. 2012): the Asian tiger mosquito (Ae. albopictus; Adhami
and Reiter 1998), the yellow-fever mosquito (Ae. aegypti; Goncalves et al. 2008),
the Asian bush mosquito (Ae. japonicus japonicus; Schaffner et al. 2009) and Ae.
koreicus (Versteirt et al. 2012). Particularly, the Asian tiger mosquito Ae. albopictus
with widespread European distribution is a competent vector for several VBDs and
therefore poses human public health risks. It is suspected that the Asian tiger mosquito was the main vector for dengue viruses in France in 2015 (Succo et al. 2016)
and for chikungunya virus in Italy in 2007 and 2017 (Rezza 2018) (autochthonous
cases in Europe 2007–2012 reviewed in Tomasello and Schlagenhauf 2013). These
cases show how human transport activities and temperature change facilitate the
establishment of vector species and highlight the importance of actively preventing
such establishments (Eritja et al. 2017; Ducheyne et al. 2018, Reuss et al. 2018,
Dhimal et al. 2018).
Despite temperature, climate change will lead to hydrological changes. For Ae.
albopictus in Europe, it is projected that Mediterranean locations will become more
unsuitable habitats due to climatic variables and changed water regimes, while suitability is increased in middle and northern Europe up to 55°N (Fischer et al. 2014).
Climate and photoperiod also alter the host-seeking and feeding activity in ticks as
well as the seasonal occurrence of vector stages (Altizer et al. 2013; Kurtenbach
et al. 2006).
4.2.3 Distributional Changes of Ticks in Europe
There are objective grounds that climate change influences the distribution and seasonal activity of disease-transmitting ticks (Ogden et al. 2014). The tick Ixodes ricinus is medically highly relevant as a vector for spirochaete bacteria Borrelia
burgdorferi, with Lyme disease extending its distribution northwards in Europe, in
a warmer climate (Lindgren et al. 2000). The taiga tick (Ixodes persulcatus), transmitting the ‘early summer’ meningo-enzephalitis virus, is currently spread from
Russia west-northwards to Scandinavia (Jaenson et al. 2016). Ticks of the genera
Dermacentor with a previously Mediterranean distribution, for instance the Coxiella
burnetti-transmitting sheep tick Dermacentor marginatus (Q fever,) are now established in cold-temperate Germany (Földvári et al. 2016). The Mediterranean tick
Hyalomma marginatum is the main vector for the emerging pathogen CrimeanCongo Hemorrhagic Fever in Europe. International livestock trading guarantees the
tick’s mobility, as ticks live on domestic animals, while the degradation of agricultural land favours the mass development of Hyalomma marginatum (Estrada-Pena
R. Müller et al.