Indicator Assessment

Water- and food-borne diseases

Indicator Assessment
Prod-ID: IND-199-en
  Also known as: CLIM 038
Published 23 Dec 2016 Last modified 20 Oct 2021
16 min read
This page was archived on 20 Oct 2021 with reason: No more updates will be done
  • It is not possible to assess whether past climate change has already affected water- and food-borne diseases in Europe, but the sensitivity of pathogens to climate factors suggest that climate change could be having effects on these diseases.
  • The number of vibriosis infections, which can be life-threatening, has increased substantially in Baltic Sea states since 1980. This increase has been linked to observed increases in sea surface temperature, which has improved environmental conditions for Vibrio species blooms in marine waters. The unprecedented number of vibriosis infections in 2014 has been attributed to the unprecedented 2014 heat wave in the Baltic region.
  • Increased temperatures could increase the risk of salmonellosis.
  • The risk of campylobacteriosis and cryptosporidiosis could increase in those regions where precipitation or extreme flooding is projected to increase.
  • Climate change can have an impact on food safety hazards throughout the food chain.

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

Time series of Baltic Sea Vibrio cases

Data sources:

Current and projected risk of vibriosis infections in the Baltic Sea region

Note: The left panel shows a risk model map during summer 2006 and the number of cases in countries reporting infections. The right panel shows a projection of the risk of infection in 2050.

Data source:

Vibrio species (non-cholera)

Brackish water and elevated ambient temperature are ideal environmental growth conditions for certainVibriospecies. These conditions can be found during the summer months in estuaries and enclosed water bodies with moderate salinity, such as the Baltic Sea. In contrast, open ocean environments do not offer appropriate growth conditions for these bacteria owing to the high salt content, lower temperature and limited nutrient content. Of the most relevance to human health are theVibriospecies that can cause vibriosis infections, includingVibrio parahaemolyticus,Vibrio vulnificusand the non-toxigenicVibrio cholerae.

Elevated levels of non-choleraVibriospecies infections have been observed during extended hot summer seasons with water temperatures above 20 °C in the Baltic Sea and the North Sea [i]. The availability of data is best for the Baltic Sea region, where a recent analysis found strong links between the temporal and spatial peaks in sea surface temperatures and the number and distribution of Vibrio infections. Figure 1 shows the observed and projected levels of Vibrio infections in the Baltic Sea region from 1982 to 2010, which was a period of unprecedented sea surface temperature warming [ii]. Increased numbers of infections can be expected based on the effects of increased temperatures under climate change scenarios. Figure 2 presents Vibrio risk maps for 2006 (left) and 2050 under elevated sea surface temperature (right). The projected increase in risk is substantial, but the absolute increase is projected to be modest owing to low current incidence rates. More recent studies in this region suggest that this warming trend has continued, with the July 2014 heat wave experienced in Sweden and Finland leading to an unprecedented number of Vibrio wound infections reported in the region, many at extremely high latitudes (e.g. >65 N) [iii]. Environmentally acquired Vibrio infections in humans associated with particularly high sea surface temperatures have also been reported along the North Sea coast of Europe in recent years [iv].

Bacterial Vibrioblooms in coastal water can be monitored on the E3 Geoportal developed by the European Centre for Disease Prevention and Control (ECDC) [v]. The tool uses daily updated remotely sensed data to examine environmentally suitable conditions forVibrio species in coastal waters internationally.


Cryptosporidiosis is an acute diarrhoeal disease caused by intracellular protozoan parasites, Cryptosporidiumspecies. Transmission is through the faecal–oral route via contaminated water, soil or food products, and the most commonly identified vehicles are contaminated drinking water and contaminated recreational water. For example, several days of heavy rain in June 2013 resulted in river flooding in eastern Germany, and activities in the dried out floodplain led to infection among children [vi]. Heavy rainfall has also been associated with the contamination of water supplies and outbreaks of cryptosporidiosis [vii], as the concentration of Cryptosporidium oocysts in river water increases significantly during rainfall events. Dry weather conditions preceding a heavy rain event have also been associated with drinking water outbreaks [viii]. Thus, heavy precipitation can result in the persistence of oocysts in the water distribution system and the infiltration of drinking water reservoirs from springs and lakes. Inadequate barriers to remove or inactivate Cryptosporidium in the public water supply have in the past resulted in a large outbreak of Cryptosporidium in Sweden [ix].


In Europe, campylobacteriosis is the most common bacterial cause of diarrhoeal disease. The association of campylobacteriosis with a number of weather-related factors, such as temperature, rainfall, humidity and sunshine is inconsistent and lacks a clear explanatory mechanism, as Campylobacterdoes not replicate outside its animal host. There is a clear seasonality to the data in a number of European countries, with more cases during the summer months, and an association with the ambient temperature that preceded the diagnosis of the cases by 10 to 14 weeks [x]. Temperature has also been found to be linked to cases in a number of studies from England and Wales [xi] but not in other countries [xii]. Rain in early spring can trigger campylobacteriosis outbreaks [xiii]. With the projected increase in heavy rainfall events in northern Europe, the risk of surface and groundwater contamination is expected to rise. Climate change might increase the use of rainwater for irrigation or drinking water during times of drought in certain locations.


Norovirus is the most common cause of viral diarrhoea in humans with a pronounced winter seasonality. Food-borne norovirus outbreaks have been linked to climate and weather events; for example, heavy rainfall and floods may lead to wastewater overflow which can contaminate shellfish farming sites. Flood water has been associated with a norovirus outbreak in Austria [xiv]. In Europe, norovirus season strength was positively associated with average rainfall in the wettest month [xv]. Water-borne transmission of the virus is probably influenced by rainfall, causing norovirus seasonality [xvi]. The magnitude of rainfall has also been related to viral contamination of the marine environment and with peaks in diarrhoea incidence [xvii]. The predicted increase of heavy rainfall events under climate change scenarios could lead to an increase in norovirus infections because floods are known to be linked to norovirus outbreaks.


Salmonellosis is the second most commonly reported gastrointestinal infection and an important cause of food-borne outbreaks in Europe. However, overall reported cases of salmonellosis have declined steadily for several years in Europe, in part because of control measures implemented in poultry production. An increase in weekly temperature has been associated with an increase in salmonellosis in different settings [xviii]. Seasonal temperatures have been linked to salmonellosis cases, but public health interventions can attenuate the effect of warmer temperature. Extreme precipitation events that result in faecal contamination events have also been associated with salmonellosis [xix]. Floods caused by heavy rainfall events may disrupt water treatment and sewage systems and contribute to increased exposure toSalmonella species and other pathogens.

Available climate change projections indicate that the average annual number of temperature-related cases of salmonellosis in Europe may increase by almost 20 000 by the 2020s, in addition to increases expected from population changes. Under a high emissions scenario, climate change could result in up to 50 % more temperature-related cases by the end of the 21st century than would be expected on the basis of population change alone. However, these estimates are associated with high uncertainty [xx]. Moreover, health promotion and food safety policies can mitigate adverse impacts on public health.

[i] C. J. Hemmer et al., ‘Global Warming: Trailblazer for Tropical Infections in Germany?’,Deutsche Medizinische Wochenschrift 132, no. 48 (2007): 2583–89; Craig Baker-Austin et al., ‘Emerging Vibrio Risk at High Latitudes in Response to Ocean Warming’,Nature Climate Change 3, no. 1 (22 July 2012): 73–77, doi:10.1038/nclimate1628; A. Sterk et al., ‘Effect of Climate Change on the Concentration and Associated Risks of Vibrio Spp. in Dutch Recreational Waters’,Risk Analysis 35, no. 9 (24 March 2015): 1717–29, doi:10.1111/risa.12365.

[ii] Baker-Austin et al., ‘Emerging Vibrio Risk at High Latitudes in Response to Ocean Warming’.

[iii] Craig Baker-Austin et al., ‘Heatwave-Associated Vibriosis, Sweden and Finland, 2014’,Emerging Infectious Diseases 22, no. 7 (2016): 1216–20, doi:10.32032/eid2207.151996.

[iv] Luigi Vezzulli et al., ‘Climate Influence on Vibrio and Associated Human Diseases during the Past Half-Century in the Coastal North Atlantic’,Proceedings of the National Academy of Sciences 113, no. 34 (23 August 2016): E5062–71, doi:10.1073/pnas.1609157113.

[v] ECDC, ‘E3 Geoportal: Vibrio Tool’, 2016,

[vi] M. Gertler et al., ‘Outbreak of Cryptosporidium Hominis Following River Flooding in the City of Halle (Saale), Germany, August 2013’,BMC Infectious Diseases 15 (2015): 88, doi:10.1186/s12879-015-0807-1.

[vii] U Aksoy et al., ‘First Reported Waterborne Outbreak of Cryptosporidiosis withCyclospora Co-Infection in Turkey’,Eurosurveillance 12, no. 7 (2007): Article 4; M. R. Hoek et al., ‘Outbreak ofCryptosporidium Parvum among Children after a School Excursion to an Adventure Farm, South West England’,Journal of Water and Health 6, no. 3 (2008): 333–38, doi:10.2166/wh.2008.060.

[viii] Gordon Nichols et al., ‘Rainfall and Outbreaks of Drinking Water Related Disease and in England and Wales’,Journal of Water and Health 7, no. 1 (March 2009): 1–8, doi:10.2166/wh.2009.143.

[ix] M. Widerstrom et al., ‘Large Outbreak of Cryptosporidium Hominis Infection Transmitted through the Public Water Supply, Sweden’,Emerging Infectious Diseases 20, no. 4 (April 2014): 581–89, doi:10.3201/eid2004.121415.

[x] G. Nylen et al., ‘The Seasonal Distribution of Campylobacter Infection in Nine European Countries and New Zealand’,Epidemiology and Infection 128, no. 3 (June 2002): 383–90.

[xi] V. R. Louis et al., ‘Temperature-Driven Campylobacter Seasonality in England and Wales’,Applied and Environmental Microbiology 71, no. 1 (January 2005): 85–92, doi:10.1128/aem.71.1.85-92.2005; C. C. Tam et al., ‘Temperature Dependence of Reported Campylobacter Infection in England, 1989-1999’,Epidemiology and Infection 134, no. 1 (February 2006): 119–25, doi:10.1017/s0950268805004899; G. L. Nichols et al., ‘Campylobacter Epidemiology: A Descriptive Study Reviewing 1 Million Cases in England and Wales between 1989 and 2011’,BMJ Open 2, no. 4 (2012): e001179, doi:10.1136/bmjopen-2012-001179.

[xii] R. S. Kovats et al., ‘Climate Variability and Campylobacter Infection: An International Study’,International Journal of Biometeorology 49, no. 4 (March 2005): 207–14, doi:10.1007/s00484-004-0241-3.

[xiii] Louis et al., ‘Temperature-Driven Campylobacter Seasonality in England and Wales’.

[xiv] Daniela Schmid et al., ‘Outbreak of Norovirus Infection Associated with Contaminated Flood Water, Salzburg, 2005’,Eurosurveillance 10, no. 24 (2005): pii=2727.

[xv] S. M. Ahmed, B. A. Lopman, and K. Levy, ‘A Systematic Review and Meta-Analysis of the Global Seasonality of Norovirus’,PLoS One 8, no. 10 (2013): e75922, doi:10.1371/journal.pone.0075922.

[xvi] J. A. Marshall and L. D. Bruggink, ‘The Dynamics of Norovirus Outbreak Epidemics: Recent Insights’,International Journal of Environmental Research and Public Health 8, no. 4 (April 2011): 1141–49, doi:10.3390/ijerph8041141.

[xvii] L Miossec et al., ‘Magnitude of rainfall on viral contamination of the marine environment during gastroenteritis epidemics in human coastal population’,Revue d’Épidémiologie et de Santé Publique 48, no. 2 (2000): S62–71.

[xviii] E. N. Naumova et al., ‘Seasonality in Six Enterically Transmitted Diseases and Ambient Temperature’,Epidemiology and Infection 135, no. 2 (19 June 2006): 281, doi:10.1017/S0950268806006698; Ying Zhang, Peng Bi, and Janet Hiller, ‘Climate Variations and Salmonellosis Transmission in Adelaide, South Australia: A Comparison between Regression Models’,International Journal of Biometeorology 52, no. 3 (11 July 2007): 179–87, doi:10.1007/s00484-007-0109-4; Nichols et al., ‘Rainfall and Outbreaks of Drinking Water Related Disease and in England and Wales’.

[xix] D. Craig, H.J. Fallowfield, and N. J. Cromar, ‘Effectiveness of Guideline Faecal Indicator Organism Values in Estimation of Exposure Risk at Recreational Coastal Sites’,Water Science and Technology 47, no. 3 (2003): 191–98; J. Martinez-Urtaza et al., ‘Influence of Environmental Factors and Human Activity on the Presence ofSalmonella Serovars in a Marine Environment’,Applied and Environmental Microbiology 70, no. 4 (2004): 2089–97, doi:10.1128/AEM.70.4.2089-2097.2004.

[xx] Paul Watkiss and Alistair Hunt, ‘Projection of Economic Impacts of Climate Change in Sectors of Europe Based on Bottom up Analysis: Human Health’,Climatic Change 112, no. 1 (2012): 101–26, doi:10.1007/s10584-011-0342-z.

Supporting information

Indicator definition

  • Time series of vibriosis infections in the Baltic Sea region
  • Current and projected risk of vibriosis infections in the Baltic Sea region


  • Number of cases per year (unitless)
  • Risk (unitless)


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

Epidemiological data for Baltic Sea Vibrio cases were collected from a variety of sources.

Associations between epidemiological data on the emergence and dynamics of Vibrio disease and sea surface temperature (SST) records were examined and extrapolated to future SST projections.

Methodology for gap filling

Not applicable

Methodology references

No methodology references available.



Methodology uncertainty

See under "Methodology".

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 038
Frequency of updates
Updates are scheduled every 4 years
EEA Contact Info


Geographic coverage

Temporal coverage


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