This interview is conducted by the EU Commission Health Emergency Preparedness and Response Authority (HERA) and can be accessed here.
We interviewed Professor Rachel Lowe, ICREA Research Professor and Global Health Resilience (GHR) Group Leader at the Barcelona Supercomputing Center (BSC), to discuss the interlinkages between climate change and the outbreaks of climate-sensitive infectious diseases, and to understand why these are increasing and expanding to new parts of the world, especially in Europe. With Professor Lowe we also talked about how shifting climate patterns could have an impact on emergency preparedness and future response efforts.
While our planet heats up due to climate change, outbreaks of climate-sensitive infectious diseases are increasing and expanding to new parts of the world, especially in Europe. Could you please explain what are the main drivers of this increase?
We are seeing increasing infectious disease threats in Europe, which is in part due to climate change but also globalization and international travel and trade. More specifically, we are seeing much more movement between areas where diseases like dengue or chikungunya are endemic, and areas in Europe where we have mosquitoes that are capable of transmitting these diseases, including Aedes mosquitoes.
In Europe, climatic conditions are becoming more suitable for a whole range of disease vectors including different mosquito species, but also ticks and phlebotomine sandflies. These vectors are capable of transmitting diseases like dengue, West Nile virus, Lyme disease, or leishmaniasis. Europe is increasingly under threat from these different pathogens, as climatic conditions are changing and becoming more suitable for these vectors for longer periods of the year and over larger geographical areas.
Could you give us a rundown of the main climate-sensitive infectious diseases that may be a potential threat to the EU?
In Europe we are particularly at threat by diseases spread by Aedes mosquitoes, notably dengue, chikungunya, and Zika virus. Over the last 50 years we have seen the global expansion of dengue and over the last couple of decades Europe has experienced more and more locally transmitted cases. For example, over the last few years dengue outbreaks have been reported in Italy, Spain, and France. Given the high level of global connectivity between areas where we are seeing explosive epidemics of these diseases, particularly in Latin America and Asia, and areas with increasingly suitable climatic conditions for the disease vectors, the risk of local transmission of arboviral diseases is on the rise in Europe.
Aedes albopictus, otherwise known as the Asian tiger mosquito, is particularly concern in Europe as it is established in at least 13 European countries, but we are also at threat from Aedes aegypti, the yellow fever mosquito, which is well adapted to urban areas and responsible for much of the dengue transmission in Latin America. This invasive mosquito species has recently emerged in Cyprus, and Europe should be on the lookout for spread across the continent as temperatures become more favourable for its establishment. Moreover, we are also seeing increasing numbers of West Nile virus cases in humans, as climate condition become more suitable for the mosquito vector, Culex pipiens. Transmission is common in birds and migratory species have helped the virus spread globally. Tick activity is also sensitive to climate change. Ixodes ticks, which are responsible for the transmission of Lyme disease and tick-borne encephalitis to humans, can survive for longer periods with milder winters and warmer springs, and are spreading to higher altitudes. We are seeing more outbreaks in places like Germany and Sweden. In the north of Europe, we are witnessing an increased risk of Vibrio infections, and this is partly due to the warming sea surface temperatures in the Baltic Sea.
From a preparedness point of view, what is being done at the European level to integrate climate data and infectious disease trends to provide more accurate predictive models? Can you share some examples of how these models have influenced policy or response strategies in climate change hotspots?
Despite the sensitivity of infectious diseases to climate variability and climate change, there are few examples of climate information being used to predict trends on a routine and operational basis. The most compressive example to date is the Vibrio Map Viewer developed by the European Centre for Disease Prevention and Control (ECDC), which is hosted on the ECDC Geoportal, which provides daily updated forecasts on Vibrio suitability for European coastal areas.
We are currently working on a Europe-wide platform for climate-sensitive infectious diseases in the framework of the IDAlert project, a Horizon Europe project which is part of the wider European Climate-Health Cluster. Within that project we are co-developing a platform, called EpiOutlook, to provide subseasonal to seasonal outlooks of climatic suitability for a range of different infectious diseases including dengue, chikungunya and Zika, malaria, leishmaniasis, Lyme disease, tick-borne encephalitis, Vibrio, and other zoonotic diseases of importance in Europe. We also track the impact of climate change on these diseases in the Lancet Countdown in Europe collaboration. And we are bringing these policy-relevant indicators to a wide range of users across Europe, so that they can have some warning of changes in the climatic suitability for these pathogens from a few weeks to a few months in advance and combine these early warnings with other sources of epidemiological intelligence to guide interventions.
I am also leading a work package in another EU-funded project called E4Warning. In E4Warning, we are specifically focusing on decision support tools for mosquito-borne diseases in both endemic and epidemic settings. Following on from a UK Space Agency funded project where we set up a dengue early warning system for Vietnam, this scheme has been expanded to other countries in Asia, and we are currently developing modelling tools to connect movement of people and vectors between endemic and epidemic settings with a specific focus on Europe.
We are working in both projects in close partnership with Mosquito Alert, which is a citizen science project designed to investigate and control disease-carrying mosquitoes. Surveillance is carried out using the Mosquito Alert app. Users can upload photographs of any kind of mosquito species that they see, as well as breeding sites, and report mosquito bites, and then, using a combination of expert epidemiologists and AI technologies, the species can be rapidly identified, and published on an open-access map. This gives an overall idea of the geographical distribution and seasonality of mosquito populations, and allows the identification of emerging species. This project has quite a wide rollout in Europe, particularly in Spain. The initiative is led by our partners at the Centre for Advanced Studies in Blanes (CEAB-CSIC) and the Pompeu Fabra University in Barcelona.
Medical countermeasures are the core business of HERA. Our department, in fact, was created in the aftermath of the COVID-19 pandemic, to strengthen Europe’s ability to ensure the provision of medical countermeasures. Do you think that extreme weather events and shifting climate patterns could also have an impact on emergency preparedness and future response efforts? If so, how?
Due to climate change, extreme climatic events are becoming increasingly unpredictable. Events such as extreme heat, storms, floods and droughts, have an impact on both health systems resilience and the risk of different climate-sensitive infectious diseases. When we see a sudden increase in hospital emissions from some kind of extreme event, then we need to be sure that the hospitals have all the medical stockpiles and supplies that they need.
And that is where the early warning systems that we are currently developing can help give some early warning, to allow for anticipatory action and to make sure that the hospitals and medical services are well resourced to be able to deal with the expected health outcomes. For example, we might see an increase in cardiovascular diseases from extreme heat, or an outbreak of an infectious disease, depending on the setting, such as, for example, waterborne diseases related to flooding.
These kinds of tools can help make sure that the health services are properly stocked and prepared, while also ready for a disruption in the supply chain and in logistics, as obviously the extreme events can impact transportation and delivery of key medical supplies. This is where we need to start bringing in different partnerships, making sure that all the different agencies are well connected, and that data and information can be rapidly shared between disaster risk management agencies, transport and environment agencies, as well as medical and public health agencies.
We can expect to see more and more climate-related health outcomes increasing the demand for health services and solutions such as vaccines and other kinds of medical supplies. Moreover, climate change is going to impact the underlying health of many populations, particularly in terms of access to safe food and water, but also from deteriorating air quality, and this can impact immune systems of the population and how susceptible they are to emerging infectious diseases.
The interplay between climate change and the spread of climate-sensitive infectious diseases presents a significant challenge to global health, highlighting the urgent need for proactive measures. How can we be better prepared?
We really need to ensure that strong partnerships are in place, to foster multi-agency interdisciplinary collaborations while also making sure that we have buy-in from all the key policymakers, to have the correct memorandum of understandings and data sharing agreements in place. We need to ensure that we can very rapidly exchange information, and not only access information. Different agencies should not only be able to work with new data types, but also have all the tools they need to integrate and harmonize these multi-sources of information, with the ultimate goal of building robust decision support and early warning and response systems.
This involves a great deal of capacity sharing, technical training, and financial and human resources able to facilitate the integration of all the information, so that the different agencies can work together to be ready for these emerging threats. This has a lot to do with cross-sector collaboration, data sharing, and training. Of course, we need to make sure that we are also building stronger health systems, to ensure that health centres can be resilient to extreme events in terms of infrastructure and supplies. But we also need to boost innovation around medical countermeasures, and enhance research and development to create new vaccines and treatments. Last but not least, we also need to make a big effort to ensure that we have an equitable distribution globally of vaccines and other kinds of supplies, with a pledge to guarantee that other parts of the globe are equally protected, and that resources are not disproportionately allocated to the high-income areas of the globe.
And key to all of this is engaging with communities, as well as enhancing public awareness and education, so that people are able to protect themselves, particularly from new emerging threats they do not necessarily think about. In Europe, examples could be destroying mosquito breeding sites that could form around the home, or ensuring that people have access to proper cooling or screens to protect themselves from the heat, and different disease vectors.
All in all, to resist these emerging infection disease threats, we need to come up with an integrated perspective, in terms of One Health partnerships, focusing more on the proactive approach rather than the reactive one.
