Climate change as a catalyst for disease proliferation

As Europe grapples with the increasingly tangible impacts of climate change, from soaring temperatures to intensifying weather extremes, a lesser-known but equally alarming consequence is emerging: the resurgence and spread of vector-borne diseases. These illnesses, transmitted by insects and ticks, were once rare or non-existent in many European countries. However, as rising temperatures expand the habitable range of these disease-carrying vectors, the threat they pose to public health grows more pressing with each passing year.

Emerging threats: The northward expansion of vector-borne diseases

The changing climate is reshaping the geographical distribution of vector-borne diseases in Europe. As Dr Jan Semenza, head of the Health Determinants Program at the European Centre for Disease Prevention and Control (ECDC), warns, "Climate change is causing an obvious northward expansion of vector-borne diseases into Europe. Mosquitoes, ticks, and other vectors are finding increasingly suitable habitats in parts of Europe where the climate used to be inhospitable for them."

This shift is primarily driven by rising temperatures. Cold-sensitive vectors like mosquitoes and ticks can survive and thrive in previously too-cool areas as the climate warms. This expansion of their habitable range brings with it the diseases they carry, exposing new populations to potentially deadly illnesses.

Recent outbreaks: A harbinger of future threats

The consequences of this climate-driven shift are already becoming apparent. In recent years, outbreaks of West Nile virus, transmitted by mosquitoes, have occurred with increasing frequency across southern and central Europe. Countries like Italy, Greece, Hungary, Romania, and Croatia have been hit particularly hard.

However, the West Nile virus is not the only concern. Tick-borne encephalitis and Lyme disease cases are also rising as ticks find more suitable habitats in a warming Europe. The sporadic appearances of tropical diseases like dengue, chikungunya, and malaria are even more worrying. These illnesses, once practically unheard of in Europe, are now emerging as rising temperatures enable their vectors to gain a foothold.

The role of rising temperatures in disease transmission

2010 marked a particularly alarming milestone, with local dengue transmission reported for the first time in France and Croatia. Small outbreaks have occurred in subsequent years, and in 2017, chikungunya spread in Italy and has since been detected in France and Spain. The Aedes aegypti and Aedes albopictus mosquitoes, which can spread these diseases, are finding increasingly large areas of southern Europe suitable habitats as summers grow hotter.

Projections and potential futures: a dramatic increase in risk

If climate change continues unabated, the future of vector-borne diseases in Europe looks even more concerning. Studies project a dramatic increase in the population at risk. One analysis estimates that the percentage of Europeans potentially exposed to mosquito-borne diseases could rise from the current 10% to a staggering 60-80% by the end of the century under the highest warming scenarios.

This expansion of risk is not uniform across Europe. Southern and eastern regions are likely to be the most affected, as they are projected to experience the greatest increases in temperature and changes in precipitation patterns. However, even areas of central and northern Europe that were previously insulated from these diseases may face new threats as vectors expand their range northward.

Policy and prevention: Necessary actions to combat an escalating threat

Combating the rising threat of vector-borne diseases in Europe will require a multi-faceted approach. Dr Giovanni Rezza, director of the Department of Infectious Diseases at the Italian National Health Institute, states, "The expanding range of invasive mosquito species is particularly concerning, as they can introduce diseases previously not seen in Europe. We need to strengthen surveillance and control measures to limit their spread."

Strengthening disease surveillance systems is crucial for early detection and rapid response to outbreaks. This involves enhancing monitoring networks, improving diagnostic capabilities, and promoting cross-border collaboration and data sharing. Based on climate and environmental data, early warning systems can help health authorities anticipate and prepare for potential outbreaks.

Vector control measures are also essential. This can include targeted insecticide spraying, elimination of mosquito breeding sites, and promotion of personal protective measures like insect repellent use and protective clothing. Public education campaigns raise awareness about the risks and prevention methods.

However, as Dr Semenza of the ECDC has emphasised, these adaptation and preparedness measures alone will not be sufficient if climate change continues unabated. He states, "Adapting to the current impacts and preparing health systems is important, but the long-term solution has to include urgent action to reduce emissions and limit climate change itself."

The crucial role of climate action

Ultimately, the resurgence of vector-borne diseases in Europe is a symptom of a much larger problem: the global climate crisis. As temperatures continue to rise due to unmitigated greenhouse gas emissions, the conditions that allow disease vectors to thrive and spread will only become more prevalent.

This means that the most effective long-term solution to this growing health threat is to address the root cause: climate change. Urgent and ambitious action to reduce emissions and limit further warming is crucial for preventing the widespread establishment of vector-borne diseases in Europe and mitigating the myriad other health risks posed by a changing climate.

This will require a concerted effort at all levels of society. Governments must enact policies to decarbonise economies and promote sustainable practices rapidly. Businesses must embrace clean technologies and reduce their carbon footprints. Individuals can contribute by adopting environmentally friendly lifestyles and advocating for change.

Hopes for COP29

The upcoming COP29 in Baku, Azerbaijan presents a crucial opportunity to address the pressing issue of climate finance. With a focus on setting a new collective quantified goal on climate finance for the post-2025 period, expectations are high for developed nations to step up their commitments and provide substantial financial resources to support developing countries in their efforts to mitigate and adapt to climate change.[3]

Achieving progress on climate finance is pivotal for the success of COP29 and the overall implementation of the Paris Agreement. Developing countries, particularly the most vulnerable nations, are in dire need of adequate and accessible funding to implement their Nationally Determined Contributions (NDCs), National Adaptation Plans (NAPs), and address loss and damage. A robust and ambitious climate finance goal, coupled with a clear roadmap for its delivery, could pave the way for enhanced global climate action and a just transition towards a low-carbon future.

Conclusion: A call for urgent and unified action

The resurgence of vector-borne diseases in Europe is a clear warning sign that the impacts of climate change on our health and well-being are already manifesting. As rising temperatures allow disease-carrying insects and ticks to expand their range, the risks to public health will only continue to grow.

Addressing this threat will require a multi-pronged approach, including strengthened disease surveillance, vector control measures, and public education. However, urgent action to tackle climate change is the most crucial element of any long-term solution.

The spread of vector-borne diseases is just one of the many ways the climate crisis impacts our world. The consequences are becoming increasingly difficult to ignore, from deadly heatwaves to devastating floods and droughts. The resurgence of these diseases in Europe is another stark reminder of the urgent need for decisive and unified action to reduce emissions and build a more sustainable future.

In the face of this growing threat, we must recognise that our planet's and our people's health are inextricably linked. By taking bold steps to address climate change, we can help prevent the spread of vector-borne diseases and create a healthier, more resilient world for future generations. The time for action is now.

References

1. "Climate change is the greatest threat to public health in Europe today, warns ECDC" https://www.ecdc.europa.eu/en/news-events/climate-change-greatest-threat-public-health-europe-today-warns-ecdc

2. "West Nile virus transmission in Europe by 2030" https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(20)30287-6/fulltext

3. "Rise in Lyme disease and other tick-borne illnesses" https://www.ecdc.europa.eu/en/news-events/rise-lyme-disease-and-other-tick-borne-illnesses 

4. "Dengue outbreak in Madeira, Portugal" https://www.who.int/csr/don/2012_10_17/en/

5. "Chikungunya – France" https://www.who.int/csr/don/23-august-2017-chikungunya-france/en/

6. "The climatic suitability for dengue transmission in Europe" https://iopscience.iop.org/article/10.1088/1748-9326/11/3/034012/meta

7. "Invasive Mosquito Populations Are Growing" https://ehp.niehs.nih.gov/doi/10.1289/EHP6186