key: cord-293365-z1h788sc
authors: Semenza, Jan C; Ebi, Kristie L
title: Climate change impact on migration, travel, travel destinations and the tourism industry
date: 2019-04-12
journal: J Travel Med
DOI: 10.1093/jtm/taz026
sha: 
doc_id: 293365
cord_uid: z1h788sc

Background: Climate change is not only increasing ambient temperature but also accelerating the frequency, duration and intensity of extreme weather and climate events, such as heavy precipitation and droughts, and causing sea level rise, which can lead to population displacement. Climate change-related reductions in land productivity and habitability and in food and water security can also interact with demographic, economic and social factors to increase migration. In addition to migration, climate change has also implications for travel and the risk of disease. This article discusses the impact of climate change on migration and travel with implications for public health practice. Methods: Literature review. Results: Migrants may be at increased risk of communicable and non-communicable diseases, due to factors in their country of origin and their country of destination or conditions that they experience during migration. Although migration has not been a significant driver of communicable disease outbreaks to date, public health authorities need to ensure that effective screening and vaccination programmes for priority communicable diseases are in place. Population growth coupled with socio-economic development is increasing travel and tourism, and advances in technology have increased global connectivity and reduced the time required to cover long distances. At the same time, as a result of climate change, many temperate regions, including high-income countries, are now suitable for vector-borne disease transmission. This is providing opportunities for importation of vectors and pathogens from endemic areas that can lead to cases or outbreaks of communicable diseases with which health professionals may be unfamiliar. Conclusion: Health systems need to be prepared for the potential population health consequences of migration, travel and tourism and the impact of climate change on these. Integrated surveillance, early detection of cases and other public health interventions are critical to protect population health and prevent and control communicabledisease outbreaks.

Travel medicine will increasingly see the health consequences of significant changes associated with global change, particularly climate change and socioeconomic development. Together these changes mean more opportunities for people to travel to pathogen-endemic countries and for pathogens to be imported to new locations, with the potential for unexpected communicable disease cases and outbreaks. Moreover, people who migrate or are displaced can also be at increased risk for chronic disease and mental health issues. Thus, travel medicine needs to take a broader perspective than just asking patients where they are going or where they have been, considering how the ongoing and projected shifts in the magnitude and pattern of disease could affect the health and well-being of individuals and populations. Modifications to the approaches used by health systems to manage adverse health outcomes are needed to ensure health care providers have the most up-to-date information.

Migration describes the movement of a person away from their usual residence whereas travel describes a person who passes from place to place, for any reason. Migration and travel have shaped the history of humanity and enriched societies economically, socially and culturally. Multiple and interacting factors drive migration in particular. Climate change, including increasing climate variability, can be one of these factors.

We discuss the potential impacts of climate change on migration and travel and the implications for travel medicine and public health practice. Following a brief review of climate change, we discuss the potential health implications of migration and travel and the way in which they are affected by climate change and provide suggestions for health systems to better manage the potential impact of climate change, migration and travel on population health.

The Intergovernmental Panel on Climate Change Special Report on warming of 1.5 • C concluded that human activities have caused ∼1.0 • C of global warming since pre-industrial times and that, if it continues to increase at the current rate, warming is likely to reach 1.5 • C between 2030 and 2052. 1 The Special Report concluded that climate change is increasing, and will continue to increase, land and ocean temperatures and the frequency, intensity and duration of heat waves in most land regions (high confidence). It also concluded that climate change will continue to increase the frequency and intensity of heavy precipitation events globally and the risk of drought in the Mediterranean region specifically (medium confidence). Climate change is a long-term process, but the extent to which individual weather events are influenced by climate change can increasingly be estimated. 2, 3 Migration The greatest human migration started 60 000 or 70 000 years ago when Homo sapiens left Africa for other parts of the world 4-7 ; a series of 'mega-droughts' may have contributed to this. [6] [7] [8] Migration has continued since and has become a defining characteristic of our times, affecting every inhabited continent. Migrants may move internally, settle in neighbouring countries or move to other continents. Currently, Europe, North America and Oceania are the main destinations for migrants although, overall, Europe and Asia have received the greatest number of migrants in recent decades. 9 Migration has political, social, economic, cultural, environmental and public health implications. Migrants generally contribute more in taxes and social contributions than they receive in benefits. [10] [11] [12] [13] But migration can also pose chal-lenges, particularly when there is a rapid influx of large numbers of people.

The international importance of migration was recognized in 2015 by the United Nations General Assembly when the 2030 Agenda for Sustainable Development was adopted; 11 of the 17 Sustainable Development Goals (SDGs) directly or indirectly relate to migration 14 (Table 1 ). In 2016, the United Nations General Assembly adopted the New York Declaration for Refugees and Migrants to support a comprehensive approach to migration. These international accords were also thematically linked to other major international agreements, including the Sendai Framework for Disaster Risk Reduction and the Paris Agreement under the United Nations Framework Convention on Climate Change. 15 ,16 The drivers of migration are complex and include political, economic, social, cultural and environmental factors (Figure 1 ). These same factors can determine whether migration is permanent or temporary. The drivers of migration can be grouped into five categories 17-19 : 1) Push factors that force people to migrate including war, unemployment, food scarcity, over-population or prosecution. 2) Pull factors that attract people to a new destination including work and educational opportunities, political or religious freedom. 3) Network drivers that facilitate the migration process such family ties, social support, kinship, safety and feasibility of transport. 4) National policies that allow or prohibit migration. 5) Personal aspirations and motivations.

These drivers are often interconnected and situation specific ( Figure 1 ). They can also interact with climate change, which can itself be a trigger for migration ( Figure 2 ). 20, 21 Although environmental drivers do not appear to have been the most significant contributor to international migration to date, 22, 23 migration in response to the consequences of climate change can be a pragmatic adaption strategy that balances the risks of staying and the risks of moving. 20, [24] [25] [26] [27] For example, for the Tonga-speaking people in Southern Zambia, migration is an adaptation strategy to climate variability when the availability of water affects both agricultural production and livestock survival. 28 Additional warming of 0.5 • C is projected to further exacerbate climate-related drivers of migration; studies suggest that an increase in extreme weather and climate events and disasters associated with climate change could trigger an increase in migration. [29] [30] [31] [32] Climate change impacts on migration and health. The complex and multiple drivers of migration mean that it is difficult to attribute specific migrations to climate change (Figures 1 and  2) . As a result, projections of migration associated with climate change vary widely, ranging from 50 million to 200 million, with these numbers based on extrapolations. 27, 33 In 2018, a World Bank report on the impact of climate change on migration estimated that by 2050-in just three regions-climate change could force more than 143 million people to move within their countries. 34 Table 2 summarizes the World Bank findings from three case studies in sub-Saharan Africa (Ethiopia), South Asia (Bangladesh) and Latin America (Mexico).

Evidence for the possible role of climate change on migration comes from different sources (Figure 1 and 2) . These include studies of the extent to which 'temperature and precipitation' are associated with out-migration. For example, in recent decades, temperature had a statistically significant effect on out-migration from agriculture-dependent countries. 35 There is a nexus between climate change and migration in that temperature and precipitation are positively associated with migration: a 1 • C increase in average temperature in the sending country is associated with a 1.9% increase in bilateral migration flows; an additional millimeter of average annual precipitation is associated with an increase in migration of 0.5%. 36 Another study suggests that an increase in precipitation anomalies from the long-term mean may also be associated with an increase in out-migration. 37 Under a moderate climate change scenario, if global mean temperature rises by 2 • C, tropical populations would have to move considerable distances in order find places where temperatures are similar to those in places they currently live in and to preserve their annual mean temperatures. 38 'Extreme weather events' linked to climate change, such as heat waves, droughts, storms, floods and wildfires, cause shortterm population displacement ( Figure 2 ). In 2017, disastersmost of which were related to extreme weather-displaced 18.8 million people in 135 countries ( Figure 3 ). 9 In 2018, California Only low-income countries show marked increases in population under SPP4. b The higher number of climate migrants under the more climate-friendly scenario in Ethiopia is in part driven by the regional climate models, which project lower water availability by 2050 in general compared with the other two scenarios (pessimistic reference and more inclusive development scenarios), which are coupled with higher emissions. experienced the most destructive wildfire season on record with more than 81,000 people being evacuated from their homes. 39 A number of factors led to these fires, including accumulated natural fuel and compounding atmospheric conditions that were linked to climate change. 40 Based on the experience of other events in the USA, some people will eventually return to their communities, but others will permanently relocate. For example, following Hurricane Katrina, it was estimated that between 37% and 54% of the population returned, 41 with young adults being more likely to have moved further away. 41 ,42 In 1992, after Hurricane Andrew in Florida, 76% of displaced residents relocated within the same county, 18% moved within the state and 6% moved out of state. 43 In some cases, extreme weather events can cause longerterm migration. For example, an increase in the frequency and intensity of droughts in Tanzania has killed livestock and forced the Maasai people to migrate from rural to urban settings, with documented implications for their mental health. 44 Similarly, prior to the Syrian migrant crisis in 2015, the Fertile Crescent was affected by a severe and sustained drought associated with anthropogenic increases in greenhouse gas emissions 45 and this, combined with unsustainable agricultural and environmental practices, contributed to internal migration, political instability and conflict and eventually to an exodus of one million migrants to Europe. 46 'River flooding and erosion' has adversely affected agriculture in Bangladesh and resulted in population migration to India ( Figure 2 ). 47 Climate change models project an increased frequency and likelihood of severe storms, with implications for sea level and flooding, in the Ganges-Brahmaputra-Meghna delta, and this is likely to displace a large number of people. 48 In Pakistan, the adverse economic impact of heat waves on agricultural and non-agricultural activity has increased outmigration. 49 In contrast, flooding in Pakistan was not associated with significantly increased migration, possibly due to the larger scale of the response by relief agencies to floods compared with heat waves. 49 In other regions, food scarcity due to flooding has contributed to internal migration. In 2018 in Mali, flooding destroyed fields, damaged grain stores and impeded livestock production and, as a result, an estimated 4.6 million people are food insecure and 77 000 internally displaced.

'Gradual changes' due to climate change, such as changing rainfall patterns, rise in sea level, increased salinization and decreased soil fertility, can also be a driver for migration ( Figure 2 ).

practice. Migration has implications for health and public health practice. 50, 51 Migrants can be exposed to health risks in their country of origin and country of destination (Figure 2) 52 ; they may be particularly at risk during their journey, due to lack of shelter, exposure to harsh climatic conditions, heat and overcrowded, inadequate transit and detention centres. 53 Public health interventions need to target migrants in all of these settings, and especially during migration, in order to minimize associated health risks (Figure 2) .

Sudden displacement because of a disaster or other event can be very stressful and manifest in post-traumatic stress disorders, depression or anxiety that can continue for months or even years. 54 Other factors that can affect the mental health of migrants include family separation, acculturation, job insecurity, restricted mobility, dangerous border crossings, stigmatization and marginalization. 55 Stress is associated with higher rates of depression and anxiety disorders in the short term and with cardiovascular disease in the longer term. [56] [57] [58] Epidemic intelligence data from the European Centre for Disease Prevention and Control (ECDC) suggests that migration is a relatively infrequent driver of communicable disease threat events in Europe, compared with travel and tourism. 59, 60 There was no evidence during the 2015 migrant crisis in Europe that migrants posed a risk to European Union citizens from communicable diseases, 61 and despite the barriers to accessing immunization that migrants experience, the contribution of migrants to the current measles outbreaks in Europe is minimal. 62 However, migrants may be at increased risk of communicable disease due to exposure or conditions during migration and in the country of destination (Table 3) . 29, 61, 63, [64] [65] [66] [67] For example, there is evidence that tuberculosis transmission occurs on migration routes to Europe, including during long-term stays in refugee camps. 68 Overcrowded and inadequate refugee camps, detention centres and housing can spread vectors (e.g. lice and fleas) that transmit diseases such as relapsing fever, trench fever and epidemic or murine typhus. 61 Poor and overcrowded living conditions can also increase the risk of respiratory diseases, such as seasonal influenza. 69 Migrants living in overcrowded conditions with poor sanitation may also be at risk of cholera outbreaks. 70 Overcrowding, poor sanitation and limited access to health services can also facilitate the emergence of antimicrobial resistance (AMR) among migrants, particularly refugees and asylum seekers. 71 Migrants may be at increased risk of communicable disease in their country of destination due to factors including lack of vaccination, low socioeconomic status and poor living conditions and limited access to health care (Table 3) . 69 Recent evidence from the European Union (EU) and the European Economic Area (EEA), based on CD4 cell counts and HIV-RNA trajectories from seroconversion also suggests that migrants may be at risk of HIV transmission in their country of destination; two-thirds of a sample of HIV-positive migrants from sub-Saharan Africa, Latin America and the Caribbean acquired their HIV infection in the country of destination. 72 Essential public health measures include ensuring adequate living conditions, access to health care in refugee camps, detention centres, screening for communicable diseases and assessment Offer serological screening and treatment (for those found to be positive) to all migrants from countries of high endemicity in sub-Saharan Africa and focal areas of transmission in Asia, South America and North Africa.

Offer serological screening and treatment (for those found to be positive) for strongyloidiasis to all migrants from countries of high endemicity in Asia, Africa, the Middle East, Oceania and Latin America.

Offer vaccination against MMR to all migrant children and adolescents without immunization records as a priority. Offer vaccination to all migrant adults without immunization records with either one dose of MMR or in accordance with the MMR immunization schedule of the host country. Offer vaccination against diphtheria, tetanus, pertussis, polio and HiB a (DTaP-IPV-Hib) to all migrant children and adolescents without immunization records as a priority. Offer vaccination to all adult migrants without immunization records in accordance with the immunization schedule of the host country. If this is not possible, adult migrants should be given a primary series of diphtheria, tetanus and polio vaccines. See Table 5 for details. CXR means chest X-ray; LTBI, latent TB infection; TST, tuberculin skin test; IGRA, interferon-gamma release assay; MMR, measles/mumps/rubella. Source: ECDC. Public health guidance on screening and vaccination for infectious diseases in newly arrived migrants within the EU/EEA. https://ecdc.europa.eu/sites/portal/files/documents/Public%20health%20guidance %20on%20screening%20and%20vaccination%20of%20migrants%20in%20the%20EU%20EEA.pdf.

Vaccination against Hib is only recommended to children up to five years of age. of vaccination status on arrival in countries of destination (Table 4 ). Available evidence shows that it is cost-effective to screen child, adolescent and adult migrants for active and latent tuberculosis, HIV, hepatitis C, hepatitis B, strongyloidiasis and schistosomiasis (Table 3) . 73 Targeted HIV prevention, testing and treatment programmes are also required in countries where migrants are at risk of HIV acquisition after arrival. There is also a clear benefit from ensuring that migrants are included in vaccination programmes and providing catch-up vaccinations where needed (Table 5) . Particular attention should be given to vulnerable children, women and the elderly, who might also suffer from non-communicable diseases, such as cardiovascular diseases, diabetes, cancer, chronic lung diseases, mental health 74 and trauma. Sudden migration can result in complications from noncommunicable diseases if treatment and care are discontinued or if access to medications is interrupted. These conditions can cause a life-threatening deterioration and acutely exacerbate preexisting conditions in the event of sudden migration (Table 6 ).

Travel, including for business and tourism, has increased dramatically in recent decades. Globally, in 2017, commercial airlines carried more than 4 billion passengers; this is projected to have risen to 4.4 billion in 2018 and to continue to increase in the coming years. 75 Air travel contributes to greenhouse gas emissions and, hence, to climate change.

At the same time, the effects of climate change on tourism assets, such as biodiversity, coral reefs, glaciers and cultural heritage, are leading to an increase in 'last chance' travel to destinations before they are further degraded. [76] [77] [78] For example, in the southern hemisphere, sea level is projected to rise by 30-150 cm by the end of this century, submerging much of the Maldives. 79 In northern latitudes, climate change is already having an adverse impact on the winter tourism industry in Lapland and may make it impossible to maintain its snowcovered winter wonderland in future. 80 In many ski resorts, artificial snowmaking, which has high energy costs, is increasingly being used to supplement natural snow, to improve reliability and to extend the season.

Climate change can be a factor in creating conditions suitable for vector-borne disease transmission. Importation of pathogens from endemic areas can then result in the subsequent spread of these diseases under suitable climatic conditions. Extended seasonal transmission seasons due to climate change can also increase the window of opportunity of pathogen importation.

Climatic suitability, including lower and upper temperature thresholds, affects the growth, abundance and survival of mosquito vectors such as Aedes aegypti and Aedes albopictus that can transmit dengue, Zika and chikungunya. In Europe, a warmer climate appears to be associated with more frequent outbreaks of dengue and chikungunya 81 are projected to become more suitable for onward transmission of the chikungunya pathogen. 82 Climate change may have contributed to the explosive spread of Zika in Brazil. 83 The epidemic was preceded by 'record warmest' climatic conditions, accompanied by a severe drought. 84 The utilization of home water storage containers during the drought might have provided breeding sites for Aedes mosquitoes and increased exposure to mosquitoes. Virus importation into a susceptible population could then have triggered the epidemic. 83 Precipitation, another important environmental factor affected by climate change, also influences the availability of conditions suitable for mosquito vectors. For example, heavy rainfall increases the abundance of A. albopictus and, hence, the risk of transmission of dengue and chikungunya. 85 Climate change can increase the risk of other vector-borne diseases, including tick-borne and rodent-borne infections, 85 and can also influence the range, seasonality and incidence of water-borne diseases such as cholera. 86, 87 Global air travel may facilitate the spread of 'resistant pathogens'. For example, it is thought to have facilitated the rapid dissemination of methicillin-resistant Staphylococcus aureus from the UK and North America across Europe and then to Asia. 88 Vancomycin-resistant enterococci and Klebsiella pneumoniae carbapenemase-producing K. pneumoniae followed a similar trajectory. 88 The burden of antibiotic resistance in destination countries can also be exacerbated by climate change, because an increase in ambient temperature is associated with a significant increase in antibiotic resistance for common pathogens, including K. pneumoniae and S. aureus. 89 It is hypothesized that temperature accelerates horizontal transfer of resistance genes or the uptake of genetic material. Ambient temperature may also facilitate environmental growth of resistant strains and enhance transmission from food, agriculture and environmental sources. 89 Climate change impacts on travel: implications for public health practice. Air travel can facilitate the spread of communicable diseases around the globe. Passenger volume has been identified as a significant driver of the importation of viremic passengers. 90, 91 Flights directly connect millions of passengers between Europe and Asia, Africa, North America and South America, with many of these locations 'hot spots' for the emergence of communicable diseases. 92 A disease outbreak in one part of the world can quickly spread to another part via air travel. 59, 60 For example, in-flight transmission of severe acute respiratory syndrome (SARS) in 2003 resulted in the rapid spread of SARS-associated coronavirus (SARS-CoV) around the world. 93 International air travellers departing from Mexico in 2009 unknowingly carried and disseminated the novel influenza virus A(H1N1)v around the world. 94 Similarly, air transport networks contributed to the spread of Middle East Respiratory Syndrome from Saudi Arabia in 2012, chikungunya dispersion in the Americas in 2013, Ebola from West Africa in 2014 and Zika spread in the Americas in 2015. [95] [96] [97] [98] More specifically, air travel can increase the risk of importation of pathogens from endemic areas into regions with competent mosquito vectors and suitable climatic and environmental conditions for vector-borne diseases. 90 Dengue, a mosquito-borne viral disease, is a significant public health concern, threatening almost half of the world's population. 99 Table 5 . Vaccinations to be offered to migrants in the absence of documented evidence of prior vaccination within the EU/EEA 64

Priority vaccinations MMR Administer to individuals ≥9 months of age. Two doses of MMR a should be administered at least 1 month apart but preferably longer according to national guidelines. Measles vaccine provided before 12 months of age does not induce protection in all and should be repeated after 12 months of age. Loss of access to medication or devices, loss of prescriptions, lack of access to health care services leading to prolongation of disruption of treatment Degradation of living conditions Loss of shelter, shortages of water and regular food supplies and lack of income add to physical and psychological strain Interruption of care Due to destruction of health infrastructure, disruption of medical supplies and the absence of health care providers who have been killed, injured or are unable to return to work Interruption of power supplies or safe water Life-threatening consequences, especially for people with end-stage renal failure who require dialysis Source: http://www.euro.who.int/en/health-topics/health-determinants/migration-and-health/migrant-health-in-the-european-region/migration-and-health-key-issues#292932 Transmission occurs largely in tropical and sub-tropical regions, but outbreaks have occurred in Europe around the Mediterranean where A. albopictus is present. 100 Infected air passengers from endemic areas can arrive in Europe during their viremic period, be bitten by local mosquito vectors and transmit the dengue virus locally and trigger an outbreak due to a warming climate. 81 Other means of transport are also implicated in the spread of disease-causing pathogens. For example, ballast from cargo ships played a role in moving pathogenic Vibrios to new locations that were environmentally and climatically suitable, even in northern latitudes. 101 Travel and tourism can also facilitate the importation of pathogens from developed countries with low vaccination coverage, to developing countries with high rates of susceptible individuals due to lack of health care access. 102, 103 Responding to the public health challenges associated with travel and climate change requires robust national surveillance systems, including effective tracking of vector location and disease importation. 104 Integrated surveillance of invasive and endemic mosquito species is crucial for effective prevention and control of vector-borne diseases. 104 Early detection of outbreaks can be aided by seasonal surveillance in areas where competent vectors are active and in close proximity to airports with a large influx of passengers from endemic areas. 90 For example, the risk of dengue importation can be described by a model that relates air travellers from dengue-affected areas to dengue importation. 90 This approach can delineate in space and time where the risk is the highest, and target seasonal surveillance to high-risk areas, for early case detection and intervention.

An important consideration when projecting risk of disease transmission associated with climate change and travel is that the timing of risks may be under-estimated, i.e. transmission may occur sooner than models suggest. For example, the modelled future environmental suitability of A. aegypti in the contiguous USA in the period 2061-2080 projects potential suitability in southern areas of mid-western states, such as Illinois, Indiana and Ohio. 105 However, breeding colonies of A. aegypti were found in Ontario in southern Canada in 2017, indicating that the risk of transmission of diseases such as dengue fever and Zika may occur earlier than the projections suggest. 106 The importation and spread of tropical pathogens in temperate regions due to climate change is another aspect to consider for public health practice. It is a potential threat to the safety of the blood supply and, hence, of blood transfusions, particularly with respect to pathogens for which there are no diagnostic tests. [107] [108] [109] [110] [111] Expansion of areas with an increased risk of communicable diseases due to climate change also increases the risk of blood bank contamination with communicable pathogens as a higher number of prospective blood donors are exposed to potential infections for a longer period, e.g. if climate change alters the length of the annual mosquito activity season. 107 Moreover, the asymptomatic phase of many infections, even if it is relatively short, increases the potential for transmission by transfusion. 112 Climate change projections of the probability of infection should therefore be used for preparedness activities. In addition, certain pathogens, such as the West Nile virus, can persist in stored blood components and subsequently cause infection through intravenous application. Pathogen reduction technology that inactivates pathogens in donated blood is a strategy that could be used for pre-emptive risk reduction. 108

The world is warmer today than in pre-industrial times, and warming is projected to continue. The frequency, duration and intensity of extreme weather events have increased, with implications for migration in particular. Global warming is associated with migration from farming communities and from small islands and coastal areas. Evidence of climate change impacts on migration in other settings is less clear. The combined impact of travel and climate change can favour the importation, establishment and spread of tropical diseases in temperate regions.

These developments require public health action, including targeted and culturally appropriate interventions and novel technologies, to prevent and control emerging health threats associated with the interaction between climate change, migration and travel. It calls for training of health care professionals to provide appropriate health care (prevention, screening, and treatment) for migrants and for risk assessment of diseases among travellers/ tourists. Adequate living conditions, screening and vaccination programmes, and medical interventions for migrants can prevent outbreaks of communicable diseases and the spread of resistant pathogens. Assessment and interventions also need to encompass chronic conditions, mental health and trauma due to migration. Targeted HIV prevention, testing and treatment programmes are also required in countries where migrants are at risk of HIV acquisition after arrival.

Effective national surveillance systems that include tracking of vector location and disease importation can inform targeted prevention and control interventions. Novel approaches including modelling the arrival of air passengers into environmentally and climatically receptive areas, to improve assessment of the risk of importation of pathogens from endemic areas, and assessment of climatic suitability, can inform seasonal surveillance or active case finding. Specific measures may be required to ensure blood safety, including pathogen reduction technology, where there is a risk of the importation and spread of tropical pathogens in temperate regions.

The authors report no financial interests or connections, direct or indirect or other situations that might raise the question of bias in the work reported or the conclusions, implications or opinions stated-including pertinent commercial or other sources of funding for the individual author(s) or for the associated department(s) or organization(s), personal relationships or direct academic competition.

J.C.S. wrote the first draft of the paper. Both authors approved the final paper.

herein are the authors' own and do not necessarily state or reflect those of ECDC. ECDC is not responsible for the data and information collation and analysis and cannot be held liable for conclusions or opinions drawn. We should like to thank Wei-Yee Leong from the Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore for her help with the figures.

None declared.

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Current perspectives in transfusion-transmitted infectious diseases: emerging and re-emerging infections

Emerging infectious disease agents and their potential threat to transfusion safety

We would like to thank the editor and the three anonymous reviewers for detailed and constructive feedback on the manuscript. We also appreciated the insightful comments and suggestions from Teymur Noori, Pontus Naucler and Senia Rosales-Klintz at ECDC. The views and opinions expressed