Indicator Assessment

Vector-borne diseases

Indicator Assessment
Prod-ID: IND-198-en
  Also known as: CLIM 037
Published 20 Dec 2016 Last modified 04 Jan 2022
29 min read
This page was archived on 20 Oct 2021 with reason: No more updates will be done
  • The transmission cycles of vector-borne diseases are sensitive to climatic factors, but disease risks are also affected by factors such as land use, vector control, human behaviour, population movements and public health capacities.
  • Climate change is regarded as the principal factor behind the observed move of the tick species Ixodes ricinus — the vector of Lyme borreliosis and tick-borne encephalitis in Europe — to higher latitudes and altitudes. Climate change is projected to lead to further northwards and upwards shifts in the distribution of Ixodes ricinus.
  • It is generally suspected that climate change has played (and will continue to play) a role in the expansion of other disease vectors, notably the Asian tiger mosquito (Aedes albopictus), which can disseminate several diseases including dengue, chikungunya and Zika, and phlebotomus sandfly species, which transmit leishmaniasis.
  • The unprecedented upsurge in the number of human West Nile fever infections in the summer of 2010 in south-eastern Europe was preceded by extreme hot spells in this region. High temperature anomalies in July were identified as contributing factors to the recurrent outbreaks in the subsequent years.

This indicator will no longer be updated.
Relevant information can be found in the European Climate and Health Observatory

Current European distribution of Ixodus ricinus ticks

Note: The maps displays information and the prsence/absence of Ixodes ricinus RED The species is known to have been present at least in one municipality within the administrative unit. YELLOW The species has been introduced in the administrative unit without confirmed establishment. LIGHT GREY No information is available on the existence of field studies on ticks.

Data source:

Known distribution of the tiger mosquito in Europe (Aedes albopictus)

Note: The maps displays information and the presence/absence of Aedes albopictus. RED: An established population (evidence of reproduction and overwintering) of the species has been observed in at least one municipality within the administrative unit. YELLOW: The species has been introduced (but without confirmed establishment) in the administrative unit within the last 5 years of the distribution status date DARK GREEN: Field surveys or studies on mosquitoes were conducted and no introduction (during the last 5 years) or no established population of the species have been reported MEDIUM GREY: No data for the last 5 years are available to local experts LIGHT GREY: No information is available about field studies on mosquitoes during the last 5 years.

Data source:

Climatic suitability for the mosquitos Aedes aegypti and Aedes albopictus in Europe

Note: This figure shows the climatic suitability for the mosquitos Aedes aegypti (left) and Aedes albopictus (right) in Europe. Darker to lighter green indicates conditions not suitable for the vector whereas yellow to red colours indicate conditions that are increasingly suitable for the vector. Grey indicates that no prediction is possible.

Data source:

Current distribution of West Nile Virus infections

Note: Districts with probable and confirmed cases of West Nile infections

Data source:

Projected change in the climatic suitability for Chikungunya transmission

Note: The maps shows the risk for Chikungunya transmission in Europe generated by combining temperature requirements of the Chikungunya virus with the climatic suitability of the vector Aedes albopictus. Projections for different time-frames are based on projections by the regional climate model COSMO-CLM for two emission scenarios (A1B, a medium scenario and B1, a low scenario). The "current situation" refers to the 1960-1990 baseline climate.

Data source:

Projected future distribution of West Nile Virus infections


Data source:

Past trends: tick-borne diseases

Tick-borne encephalitis (TBE) and Lyme borreliosis (Lyme disease) are the two most important tick-borne diseases in Europe, both of which are transmitted primarily by Ixodes ricinus. Lyme disease is the most common vector-borne disease in the EU, with a reported incidence of approximately 65 000 cases per year. However, there is no standardised case definition or diagnosis for Lyme disease in Europe, so this number represents only a best estimate. The number of reported cases of TBE in the EU was 2 560 during 2012. The mean annual reporting of TBE cases has increased by approximately 400 % in European endemic areas over the past 30 years, although this is almost certainly the result of more robust detection methods and diagnosis [i].

A key determinant of the number of reported cases is the abundance of ticks, a factor which is sensitive to climatic variables, notably temperature and humidity. Currently,Ixodes ricinusis present across much of continental Europe (Figure 1). There have already been reports on the northerly migration of the tick species in Sweden [ii], and to higher altitudes in the Czech Republic and Austria [iii]. Range shifts have also been observed in Germany and Norway [iv].

A high incidence of tick-borne disease is correlated with mild winters and warm, humid summers in Hungary, Slovakia and Sweden, although this could be the result of climate effects on human behaviour [v]. A high risk of Lyme disease has been associated with mild winters, high summer temperatures, low seasonal variation of temperatures and high scores on vegetation indices [vi]. There are considerable differences between the distribution of ticks and the observed incidence of TBE [vii]. It is not currently possible to assess the relative importance of climatic changes and of other factors influencing disease incidence, including vaccination coverage, tourism patterns, public awareness, distribution of rodent host populations and socio-economic conditions [viii]. There is limited evidence that other tick-borne diseases may be sensitive to climate change. Some models have suggested that the Mediterranean basin has become suitable for an expansion of Crimean–Congo haemorrhagic fever [ix], but demographic factors, farming practices and land-use change may be more important drivers [x]. The distribution of Rickettsia has also expanded in recent years, but the reasons for this are not yet well understood [xi], and few if any recent studies have interrogated the links between rickettsia diseases and climate change.

Past trends: mosquito-borne diseases

Mosquito habitats are influenced by temperature, humidity and precipitation levels. The Asian tiger mosquito (Aedes albopictus) is an important vector in Europe for transmitting viral diseases, including Zika, chikungunya and dengue. The first record of its establishment was in Italy in 1990, and Aedes albopictusis now present in several EU countries and in some countries neighbouring the EU (Figure 2). It has substantially extended its range in recent years, aided by trade and travel. It is generally suspected that climate change has also played a role in this expansion, but the extent to which this is the case is unclear [xii]. The introduction and geographical expansion of the distribution of Aedes albopictus within Europe has coincided with favourable climatic suitability for the mosquito in the Balkans, Italy, France and Benelux and in western Germany, on the eastern coast of Spain and on the eastern coast of the Adriatic Sea [xiii]. Other parts of Europe are also climatically suitable for Aedes albopictus, even if they have not recorded the presence of the vector (Figure 3) [xiv].

Mosquito-borne diseases have not been a substantial concern within Europe until recently. However, locally transmitted (i.e. autochthonous) outbreaks of chikungunya, dengue and even malaria have occurred in recent years [xv]. Several disease outbreaks transmitted by Aedes. albopictus have been reported in Europe: chikungunya in Italy and in France in 2010, 2014 and 2015, as well as local transmissions of dengue in France and Croatia in 2010 [xvi]. Heavy rainfall events may have increased the risk of the autochthonous transmission of chikungunya in France in 2014 by leading to a rapid rise in vector abundance [xvii]. No autochthonous transmission of dengue has been reported in Europe since 2010.

The risk of travellers importing Zika, dengue or chikungunya coincides with the seasons and locations of active Aedes albopictusin Europe [xviii]. With continued expansion of Aedes albopictus in continental Europe, the risk of further introduction and transmission of Zika, chikungunya and dengue will continue to exist. The risk of chikungunya introductions into Europe via returning travellers has probably increased following the large-scale outbreak of chikungunya that began in the Caribbean in late 2013 and has subsequently continued in many American countries [xix].

Aedes albopictusis not the primary vector for dengue and, although some parts of Europe are currently climatically suitable to its primary vector (Aedesaegypti), the risk of significant dengue transmission in continental Europe is currently very low, providing that the vector remains unestablished and control measures are in place [xx]. Aedes aegypti has, however, been responsible for dengue outbreaks in European territories, such as the 2013 outbreak in Madeira, Portugal [xxi].

Malaria was largely eradicated in Europe in the second half of the 20th century. However, the malaria vectors (Anopheles mosquitos) are still present in much of the European Union, and a few sporadic cases of local transmission occur each year [xxii]. The risk of malaria re-establishment in a particular region depends on climatic and ecological factors, as well as human vulnerabilities to infection. During 2009–2012, Greece experienced autochthonous malaria transmission; temperature and other environmental variables were identified as determinants of environmental suitability [xxiii]. However, socio-economic development is a key mitigating factor of malaria risk [xxiv], which therefore remains very low throughout Europe.

West Nile virus (WNV) infections in humans can be quite severe, particularly among the elderly, but many other cases can go unnoticed (more than 60 % are asymptomatic) and occur through mosquito (Culexspecies) bites. Cases can also be acquired through blood transfusion or organ, tissue and cell transplantations and, although rare, such cases have been reported [xxv]. 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 (Figure 4) [xxvi]. Positive temperature anomalies from the monthly averages were the most important determinants of the 2010 WNV outbreak [xxvii]. 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 [xxviii].

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 [xxix]. Climate change was suggested as one possible reason for the observed northwards expansion of sandfly vectors in Italy [xxx]. The contemporary risk for central Europe has been estimated to be low owing to temperature constraints on pathogen growth [xxxi].

Projections: tick-borne diseases

Cold temperatures appear to determine the altitudinal and latitudinal limits of Ixodes ricinus[xxxii]. 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 [xxxiii]. One climate projection model anticipates a 3.8 % overall habitat expansion for Ixodes ricinus in Europe by 2040–2060, with expansion into higher altitudes and latitudes (notably Scandinavia and the Baltic countries) and a contraction in some areas including the Alps, the Pyrenees, the interior of Italy and north-western Poland [xxxiv]. This aligns with other models of climate change that anticipate Ixodes ricinus range expansions under climate change scenarios [xxxv], but it has been acknowledged that many uncertainties exist in these models and that extrapolating the projected habitat range of ticks to generate projections of the incidence of tick-borne disease leads to additional uncertainties.

Nonetheless, the incidence of TBE may shift to higher altitudes and latitudes along with the distribution of Ixodes ricinus, potentially increasing the risk in some parts of northern and central Europe, unless targeted vaccination programmes and TBE surveillance are introduced. Similarly, TBE risk is generally expected to decrease in southern Europe. Warmer winters may facilitate the expansion of Lyme disease to higher latitudes and altitudes, particularly in northern Europe, but it would decrease in the parts of Europe that are projected to experience increased droughts [xxxvi].

Projections: mosquito-borne diseases

Various studies have found that warm seasonal and annual temperature and sufficient rainfall provide favourable climatic conditions for Aedes albopictusin Europe [xxxvii]. The climatic suitability for Aedes albopictus is projected to increase where climate models project warmer and wetter climates, such as south-eastern United Kingdom [xxxviii], the Balkans and central Europe, while suitability generally decreases where climate becomes drier, such as in some regions of Spain and Portugal [xxxix]. This corresponds with a modelling study that demonstrated a general decline in habitat suitability in southern Europe and the Mediterranean area, and an increase in habitat suitability in northern and eastern European countries [xl].

The risk of chikungunya may increase in Europe, particularly in those regions where the seasonal activity of Aedes albopictusaligns with the seasonality of endemic chikungunya infections abroad, thereby potentially increasing the risk of importation via travellers [xli]. Models of chikungunya transmission in Europe under climate change scenarios have identified France, northern Italy and the Pannonian Basin (east-central Europe) as the areas at highest risk, with increases in the level of risk in much of western Europe, including the Benelux countries and Germany. In contrast, Mediterranean regions demonstrated a decreased risk, although the models suggested that they will mostly remain climatically suitable for chikungunya transmission (Figure 5) [xlii].

A climate-related increase in the density or active season ofAedes albopictuscould lead to a small increase in the risk of dengue in Europe. The risk could also increase if the temperature increase facilitated the re-establishment ofAedes aegypti, the primary dengue vector. Further modelling studies are required to assess whether climate change would increase or decrease the climatic suitability forAedes aegyptiin continental Europe.

Some malaria models suggest that there will be increased suitability for malaria transmission in continental Europe under future climate change, but projected malaria impacts are highly sensitive to model design [xliii]. Nevertheless, socio-economic development, land-use and public health control measures would most likely be sufficient to mitigate the risk of malaria at the fringes of its distribution, despite the likelihood of sporadic introductions of the parasite through global travel [xliv].

Climate change has previously not been expected to have a significant impact on WNV transmission in Europe [xlv]. However, climate change could influence the transmission of the virus by affecting the geographical distribution of vectors and pathogens, by changing the migratory patterns of bird populations and through changes in the life cycle of bird-associated pathogens. Temperature increases could also play a role. The WNV risk in Europe has been projected into 2025 and 2050, with July temperature projections under a medium emissions scenario (IPCC Special Report on Emissions Scenarios (SRES) A1B), keeping other variables constant (e.g. state of vegetation, water bodies and bird migratory routes) [xlvi]. The results reveal a progressive expansion of areas with an elevated probability for WNV infections, particularly at the edges of the transmission areas (Figure 6). Projections for 2025 show an increased probability of WNV infection in eastern Croatia, north-eastern Greece and north-western Turkey; high-risk areas will have expanded even more by 2050.

Projections: sandfly-borne diseases

Future climate change could have an impact on the distribution of leishmaniasis by affecting the abundance of vector species and parasite development. Recent modelling indicates that the central European climate will become increasingly suitable for Phlebotomus species of sandflies [xlvii]. One modelling study concluded that, by the end of the 2060s, France, Germany, western Poland and southern United Kingdom could be colonised by sandfly species, principally Phlebotomus ariasi and Phlebotomus pernicious, while the entire Mediterranean Basin, Balkan Peninsula and Pannonian Basin would all be potentially climatically suitable habitats for many Phlebotomus species [xlviii]. Such expansions of sandfly species would increase the risk of leishmaniasis, but may be somewhat constrained by the limited migration ability of sandflies. The risk of disease transmission may also decrease in some areas in southern Europe where climate conditions become too hot and dry for vector survival.

[i] J. M. Medlock et al., ‘Driving Forces for Changes in Geographical Distribution of Ixodes Ricinus Ticks in Europe’,Parasites and Vectors 6 (2013): 1, doi:10.1186/1756-3305-6-1; ECDC, ‘Annual Epidemiologic Report 2014: Emerging and Vector-Borne Diseases’ (Stockholm: European Centre for Disease Prevention and Control, 2014).

[ii] T. G. T. Jaenson et al., ‘Changes in the Geographical Distribution and Abundance of the Tick Ixodes Ricinus during the Past 30 Years in Sweden’,Parasites and Vectors 5, no. 1 (2012): 8, doi:10.1186/1756-3305-5-8.

[iii] M. Daniel et al., ‘Shift of the Tick Ixodes Ricinus and Tick-Borne Encephalitis to Higher Altitudes in Central Europe’,European Journal of Clinical Microbiology & Infectious Diseases 22, no. 5 (May 2003): 327–28, doi:10.1007/s10096-003-0918-2; F. X. Heinz et al., ‘Emergence of Tick-Borne Encephalitis in New Endemic Areas in Austria: 42 Years of Surveillance’,Eurosurveillance 20, no. 13 (2015): 21077, doi:/10.2807/1560-7917.ES2015.20.13.21077.

[iv] J. C Semenza and B. Menne, ‘Climate Change and Infectious Diseases in Europe’,The Lancet Infectious Diseases 9, no. 6 (June 2009): 365–75, doi:10.1016/S1473-3099(09)70104-5.

[v] R. S. Ostfeld and J. L. Brunner, ‘Climate Change and Ixodes Tick-Borne Diseases of Humans’,Philosophical Transactions of the Royal Society B: Biological Sciences 370, no. 1665 (2015): 1–11, doi:10.1098/rstb.2014.0051.

[vi] A. Estrada-Pena et al., ‘Correlation of Borrelia Burgdorferi Sensu Lato Prevalence in Questing Ixodes Ricinus Ticks with Specific Abiotic Traits in the Western Palearctic’,Applied and Environmental Microbiology 77, no. 11 (2011): 3838–45, doi:10.1128/AEM.00067-11.

[vii] Jochen Süss et al., ‘TBE Incidence versus Virus Prevalence and Increased Prevalence of the TBE Virus in Ixodes Ricinus Removed from Humans’,International Journal of Medical Microbiology 296 (2006): 63–68.

[viii] Sarah E. Randolph, ‘Tick-Borne Encephalitis Incidence in Central and Eastern Europe: Consequences of Political Transition’,Microbes and Infection 10, no. 3 (2008): 209–16.

[ix] Helena C. Maltezou and Anna Papa, ‘Crimean–Congo Hemorrhagic Fever: Risk for Emergence of New Endemic Foci in Europe?’,Travel Medicine and Infectious Disease 8, no. 3 (2010): 139–43.

[x] A. Estrada-Peña et al., ‘Unraveling the Ecological Complexities of Tick-Associated Crimean-Congo Hemorrhagic Fever Virus Transmission: A Gap Analysis for the Western Palearctic’,Vector-Borne and Zoonotic Diseases 12, no. 9 (2012): 743–52, doi:10.1089/vbz.2011.0767.

[xi] F. Gouriet, J. M. Rolain, and D. Raoult, ‘Rickettsia Slovaca Infection, France’,Emerging Infectious Diseases 12, no. 3 (2006): 521–23.

[xii] Cyril Caminade et al., ‘Suitability of European Climate for the Asian Tiger Mosquito Aedes Albopictus: Recent Trends and Future Scenarios’,Journal of The Royal Society Interface 9, no. 75 (25 April 2012): 2708–17, doi:10.1098/rsif.2012.0138.

[xiii] Caminade et al., ‘Suitability of European Climate for the Asian Tiger Mosquito Aedes Albopictus’.

[xiv] D. J. Rogers, J. E. Suk, and J. C. Semenza, ‘Using Global Maps to Predict the Risk of Dengue in Europe’,Acta Tropica 129, no. 1 (2014): 1–14, doi:10.1016/j.actatropica.2013.08.008; Y. Proestos et al., ‘Present and Future Projections of Habitat Suitability of the Asian Tiger Mosquito, a Vector of Viral Pathogens, from Global Climate Simulation’,Philosophical Transactions of the Royal Society B: Biological Sciences 370, no. 1665 (2015): 1–16, doi:10.1098/rstb.2013.0554.

[xv] ECDC, ‘Annual Epidemiologic Report 2014: Emerging and Vector-Borne Diseases’.

[xvi] G Rezza et al., ‘Infection with Chikungunya Virus in Italy: An Outbreak in a Temperate Region’,The Lancet 370, no. 9602 (December 2007): 1840–46, doi:10.1016/S0140-6736(07)61779-6; G. La Ruche et al., ‘First Two Autochthonous Dengue Virus Infections in Metropolitan France, September 2010’,Eurosurveillance 15, no. 39 (2010): pii=19676; I. Gjenero-Margan et al., ‘Autochthonous Dengue Fever in Croatia, August–September 2010’,Eurosurveillance 16, no. 9 (2011): pii=19805; Marc Grandadam et al., ‘Chikungunya Virus, Southeastern France’,Emerging Infectious Diseases 17, no. 5 (May 2011): 910–13, doi:10.3201/eid1705.101873; E. Delisle et al., ‘Chikungunya Outbreak in Montpellier, France, September to October 2014’,Eurosurveillance 20, no. 17 (2015): 21108, doi:10.2807/1560-7917.ES2015.20.17.21108.

[xvii] David Roiz et al., ‘Climatic Factors Driving Invasion of the Tiger Mosquito (Aedes Albopictus) into New Areas of Trentino, Northern Italy’,Public Library of Science ONE 6, no. 4 (15 April 2011): e14800, doi:10.1371/journal.pone.0014800; ECDC, ‘Rapid Risk Assessment: Chikungunya Case in Spain without Travel History to Endemic Areas’ (Stockholm: European Centre for Disease Prevention and Control, 2015),

[xviii] J. C. Semenza et al., ‘International Dispersal of Dengue through Air Travel: Importation Risk for Europe’,PLoS Neglected Tropical Diseases 8, no. 12 (2014): e3278, doi:10.1371/journal.pntd.0003278.

[xix] W. Van Bortel et al., ‘Chikungunya Outbreak in the Caribbean Region, December 2013 to March 2014, and the Significance for Europe’,Eurosurveillance 19, no. 13 (2014): 20759, doi:10.2807/1560-7917.ES2014.19.13.20759.

[xx] ECDC, ‘The Climatic Suitability for Dengue Transmission in Continental Europe’, ECDC Technical Report (Stockholm: European Centre for Disease Prevention and Control, 2012),

[xxi] ECDC, ‘Dengue Outbreak in Madeira, Portugal’, Mission Report (Stockholm: European Centre for Disease Prevention and Control, 2013),

[xxii] S. A. Florescu et al., ‘Plasmodium Vivax Malaria in a Romanian Traveller Returning from Greece, August 2011’,Eurosurveillance 16, no. 35 (2011): pii=19954.

[xxiii] B. Sudre et al., ‘Mapping Environmental Suitability for Malaria Transmission, Greece’,Emerging Infectious Diseases 19, no. 5 (2013): 784–86, doi:10.3201/eid1905.120811.

[xxiv] P.W. Gething et al., ‘Climate Change and the Global Malaria Recession’,Nature 465, no. 7296 (2010): 342–45.

[xxv] L. R. Petersen, A. C. Brault, and R. S. Nasci, ‘West Nile Virus: Review of the Literature’,JAMA 310, no. 3 (17 July 2013): 308–15, doi:10.1001/jama.2013.8042.

[xxvi] S. Paz and J. C. Semenza, ‘Environmental Drivers of West Nile Fever Epidemiology in Europe and Western Asia — A Review’,International Journal of Environmental Research and Public Health 10, no. 8 (August 2013): 3543–62, doi:10.3390/ijerph10083543; Jan C. Semenza et al., ‘Climate Change Projections of West Nile Virus Infections in Europe: Implications for Blood Safety Practices’,Environmental Health 15, no. 1 (2016): 125–36, doi:10.1186/s12940-016-0105-4.

[xxvii] S. Paz et al., ‘Permissive Summer Temperatures of the 2010 European West Nile Fever Upsurge’,PLoS One 8, no. 2 (2013): e56398, doi:10.1371/journal.pone.0056398.

[xxviii] A. Tran et al., ‘Environmental Predictors of West Nile Fever Risk in Europe’,International Journal of Health Geographics 13 (2014): 26, doi:10.1186/1476-072x-13-26; M. Marcantonio et al., ‘Identifying the Environmental Conditions Favouring West Nile Virus Outbreaks in Europe’,PLoS One 10, no. 3 (2015): e0121158, doi:10.1371/journal.pone.0121158.

[xxix] Paul D. Ready, ‘Leishmaniasis Emergence in Europe’,Eurosurveillance 15, no. 10 (2010): pii=19505.

[xxx] Michele Maroli et al., ‘The Northward Spread of Leishmaniasis in Italy: Evidence from Retrospective and Ongoing Studies on the Canine Reservoir and Phlebotomine Vectors’,Tropical Medicine & International Health 13, no. 2 (2008): 256–64, doi:10.1111/j.1365–3156.2007.01998.x.

[xxxi] D. Fischer, S. M. Thomas, and C. Beierkuhnlein, ‘Temperature-Derived Potential for the Establishment of Phlebotomine Sandflies and Visceral Leishmaniasis in Germany’,Geospatial Health 5, no. 1 (2010): 59–69.

[xxxii] Ostfeld and Brunner, ‘Climate Change and Ixodes Tick-Borne Diseases of Humans’.

[xxxiii] Thomas G. T. Jaenson and E. Lindgren, ‘The Range of Ixodes Ricinus and the Risk of Contracting Lyme Borreliosis Will Increase Northwards When the Vegetation Period Becomes Longer’,Ticks and Tick-Borne Diseases 2, no. 1 (2011): 44–49.

[xxxiv] M. Boeckmann and T. A. Joyner, ‘Old Health Risks in New Places? An Ecological Niche Model for I. Ricinus Tick Distribution in Europe under a Changing Climate’,Health and Place 30 (2014): 70–77, doi:10.1016/j.healthplace.2014.08.004.

[xxxv] A. Estrada-Peña, N. Ayllón, and J. de la Fuente, ‘Impact of Climate Trends on Tick-Borne Pathogen Transmission’,Frontiers in Physiology 3 (2012): 64, doi:10.3389/fphys.2012.00064; D. Porretta et al., ‘Effects of Global Changes on the Climatic Niche of the Tick Ixodes Ricinus Inferred by Species Distribution Modelling’,Parasites and Vectors 6 (2013): 271, doi:10.1186/1756-3305-6-271.

[xxxvi] Semenza and Menne, ‘Climate Change and Infectious Diseases in Europe’.

[xxxvii] Roiz et al., ‘Climatic Factors Driving Invasion of the Tiger Mosquito (Aedes Albopictus) into New Areas of Trentino, Northern Italy’.

[xxxviii] J. M. Medlock and S. A. Leach, ‘Effect of Climate Change on Vector-Borne Disease Risk in the UK’,The Lancet Infectious Diseases 15, no. 6 (2015): 721–30, doi:10.1016/S1473-3099(15)70091-5.

[xxxix] Caminade et al., ‘Suitability of European Climate for the Asian Tiger Mosquito Aedes Albopictus’.

[xl] Proestos et al., ‘Present and Future Projections of Habitat Suitability of the Asian Tiger Mosquito, a Vector of Viral Pathogens, from Global Climate Simulation’.

[xli] Rémi N. Charrel, Xavier de Lamballerie, and Didier Raoult, ‘Seasonality of Mosquitoes and Chikungunya in Italy’,The Lancet Infectious Diseases 8, no. 1 (2008): 5–6.

[xlii] D. Fischer et al., ‘Climate Change Effects on Chikungunya Transmission in Europe: Geospatial Analysis of Vector’s Climatic Suitability and Virus’ Temperature Requirements’,International Journal of Health Geographics 12 (2013): 51, doi:10.1186/1476-072X-12-51.

[xliii] C. Caminade et al., ‘Impact of Climate Change on Global Malaria Distribution’,Proceedings of the National Academy of Sciences 111, no. 9 (4 March 2014): 3286–91, doi:10.1073/pnas.1302089111.

[xliv] Semenza et al., ‘International Dispersal of Dengue through Air Travel: Importation Risk for Europe’.

[xlv] P. Gale et al., ‘Assessing the Impact of Climate Change on Vector-Borne Viruses in the EU through the Elicitation of Expert Opinion’,Epidemiology and Infection 138, no. 2 (2009): 214; E. A. Gould and S. Higgs, ‘Impact of Climate Change and Other Factors on Emerging Arbovirus Diseases’,Transactions of the Royal Society of Tropical Medicine and Hygiene 103, no. 2 (2009): 109–21.

[xlvi] Semenza et al., ‘Climate Change Projections of West Nile Virus Infections in Europe’.

[xlvii] Dominik Fischer et al., ‘Combining Climatic Projections and Dispersal Ability: A Method for Estimating the Responses of Sandfly Vector Species to Climate Change’,PLoS Neglected Tropical Diseases 5, no. 11 (2011): e1407, doi:10.1371/journal.pntd.0001407.

[xlviii] A. J. Trájer et al., ‘The Effect of Climate Change on the Potential Distribution of the European Phlebotomus Species’,Applied Ecology and Environmental Research 11, no. 2 (2013): 189–208.

Supporting information

Indicator definition

  • Current distribution of Ixodes ricinus ticks
  • Current distribution of Aedes albopictus
  • Climatic suitability for the mosquitos Aedes aegypti and Aedes albopictus
  • Current distribution of West Nile virus infections
  • Projected change in the climatic suitability for chikungunya transmission
  • Projected distribution of West Nile Virus infections


  • Presence vs. absence of various vectors and infections (unitless)
  • Climatic suitability (%)


Policy context and targets

Context description

In April 2013, the European Commission (EC) presented the EU Adaptation Strategy Package. This package consists of the EU Strategy on adaptation to climate change (COM/2013/216 final) and a number of supporting documents. The overall aim of the EU Adaptation Strategy is to contribute to a more climate-resilient Europe.

One of the objectives of the EU Adaptation Strategy is Better informed decision-making, which will be achieved by bridging the knowledge gap and further developing the European climate adaptation platform (Climate-ADAPT) as the ‘one-stop shop’ for adaptation information in Europe. Climate-ADAPT has been developed jointly by the EC and the EEA to share knowledge on (1) observed and projected climate change and its impacts on environmental and social systems and on human health, (2) relevant research, (3) EU, transnational, national and subnational adaptation strategies and plans, and (4) adaptation case studies.

Further objectives include Promoting adaptation in key vulnerable sectors through climate-proofing EU sector policies and Promoting action by Member States. Most EU Member States have already adopted national adaptation strategies and many have also prepared action plans on climate change adaptation. The EC also supports adaptation in cities through the Covenant of Mayors for Climate and Energy initiative.

In September 2016, the EC presented an indicative roadmap for the evaluation of the EU Adaptation Strategy by 2018.

In November 2013, the European Parliament and the European Council adopted the 7th EU Environment Action Programme (7th EAP) to 2020, ‘Living well, within the limits of our planet’. The 7th EAP is intended to help guide EU action on environment and climate change up to and beyond 2020. It highlights that ‘Action to mitigate and adapt to climate change will increase the resilience of the Union’s economy and society, while stimulating innovation and protecting the Union’s natural resources.’ Consequently, several priority objectives of the 7th EAP refer to climate change adaptation.


No targets have been specified.

Related policy documents

  • 7th Environment Action Programme
    DECISION No 1386/2013/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 20 November 2013 on a General Union Environment Action Programme to 2020 ‘Living well, within the limits of our planet’. In November 2013, the European Parliament and the European Council adopted the 7 th EU Environment Action Programme to 2020 ‘Living well, within the limits of our planet’. This programme is intended to help guide EU action on the environment and climate change up to and beyond 2020 based on the following vision: ‘In 2050, we live well, within the planet’s ecological limits. Our prosperity and healthy environment stem from an innovative, circular economy where nothing is wasted and where natural resources are managed sustainably, and biodiversity is protected, valued and restored in ways that enhance our society’s resilience. Our low-carbon growth has long been decoupled from resource use, setting the pace for a safe and sustainable global society.’
  • Climate-ADAPT: Adaptation in EU policy sectors
    Overview of EU sector policies in which mainstreaming of adaptation to climate change is ongoing or explored
  • Climate-ADAPT: Country profiles
    Overview of activities of EEA member countries in preparing, developing and implementing adaptation strategies
  • DG CLIMA: Adaptation to climate change
    Adaptation means anticipating the adverse effects of climate change and taking appropriate action to prevent or minimise the damage they can cause, or taking advantage of opportunities that may arise. It has been shown that well planned, early adaptation action saves money and lives in the future. This web portal provides information on all adaptation activities of the European Commission.
  • EU Adaptation Strategy Package
    In April 2013, the European Commission adopted an EU strategy on adaptation to climate change, which has been welcomed by the EU Member States. The strategy aims to make Europe more climate-resilient. By taking a coherent approach and providing for improved coordination, it enhances the preparedness and capacity of all governance levels to respond to the impacts of climate change.
  • Implementing the European Regional Framework for Action to protect health from climate change
    How far have Member States in the WHO European Region progressed in implementing the European Commitment to Act on climate change and health? This was the question addressed to members of the Working Group on Health in Climate Change (HIC) of the European Environment and Health Task Force in summer 2012. The HIC members were asked to respond to a comprehensive questionnaire to assess the current status of health-relevant climate change mitigation and adaptation actions. A total of 22 Member States answered the questions focusing on eight thematic areas or topics: governance, vulnerability, impact and adaptation assessments, national and subnational adaptation strategies, climate-change mitigation, strengthening of health systems, awareness raising and capacity building, green health services and sharing best practices. This publication describes and analyses their responses.


Methodology for indicator calculation

The maps for the distribution of ticks and of the Aedes mosquitoes are the outcome of the collaborative work of VectorNet and are based on collecting existing data by the network members. VectorNet is a joint initiative of the European Food Safety Agency (EFSA) and the European Centre for Disease Prevention and Control (ECDC) that started in May 2014. The project supports the collection of data on vectors, related to both animal and human health.

Simulations are used for the climatic suitability for the mosquitos Aedes albopictus and Aedes aegypti in Europe.

The map for the current distribution of West Nile virus infections has been produced based on reported cases on the spatial resolution of NUTS-3 regions.

The risk for Chikungunya transmission in Europe has been estimated by combining temperature requirements of the Chikungunya virus with the climatic suitability of the vector Aedes albopictus. Projections for different time-frames are based on projections by the regional climate model COSMO-CLM for two emission scenarios (A1B, a medium scenario and B1, a low scenario). The "current situation" refers to the 1960-1990 baseline climate.

The West Nile virus risk in Europe has been projected into 2025 and 2050 based on July temperature projections under a medium emissions scenario (A1B), keeping other variables constant (e.g. state of vegetation, water bodies and bird migratory routes).

Methodology for gap filling

Not applicable

Methodology references

No methodology references available.



Methodology uncertainty

Not applicable

Data sets uncertainty

The attribution of health effects to climate change is difficult owing to the complexity of interactions and the potential modifying effects of a range of other factors (such as land-use changes, public health preparedness and socio-economic conditions). Criteria for defining a climate-sensitive health impact are not always well identified, and their detection sometimes relies on complex observational or prospective studies, applying a mix of epidemiological, statistical and/or modelling methodologies. Furthermore, these criteria, as well as the completeness and reliability of observations, may differ between regions and/or institutions, and they may change over time. Data availability and quality are crucial in climate change and human health assessments, both for longer term changes in climate-sensitive health outcomes and for health impacts of extreme events. The monitoring of climate-sensitive health effects is currently fragmentary and heterogeneous. All these factors make it difficult to identify significant trends in climate-sensitive health outcomes over time, and to compare them across regions. In the absence of reliable time series, more complex approaches are often used to assess the past, current and future impacts of climate change on human health.

The links between climate change and health have been the subject of intense research in Europe in the early 2000s (e.g. the projects cCASHh, EDEN, EDENext and Climate-TRAP); more recently health has been incorporated, to a minor extent, into some cross-sectorial projects (e.g. CIRCE, PESETA II, IMPACT2C and RAMSES). Furthermore, the World Health Organization (WHO) has a policy, country support and research mandate given by its 193 Member States through the World Health Assembly on all aspects of climate change and health. The European Centre for Disease Prevention and Control (ECDC) assesses the effects of climate change on infectious diseases and has also established a pan-EU network dedicated to vector surveillance (VBORNET).

Rationale uncertainty

No uncertainty has been specified

Data sources

Other info

DPSIR: Impact
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
Indicator codes
  • CLIM 037
Frequency of updates
Updates are scheduled every 4 years
EEA Contact Info


Geographic coverage

Temporal coverage