umu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Liu-Helmersson, Jing
Alternative names
Publications (10 of 16) Show all publications
Liu-Helmersson, J., Rocklöv, J., Sewe, M. & Brännström, Å. (2019). Climate change may enable Aedes aegypti infestation in major European cities by 2100. Environmental Research, 172, 693-699
Open this publication in new window or tab >>Climate change may enable Aedes aegypti infestation in major European cities by 2100
2019 (English)In: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 172, p. 693-699Article in journal (Refereed) Published
Abstract [en]

Background: Climate change allows Aedes aegyptito infest new areas. Consequently, it enables the arboviruses the mosquito transmits - e.g., dengue, chikungunya, Zika and yellow fever – to emerge in previously uninfected areas. An example is the Portuguese island of Madeira during 2012–13.

Objective: We aim to understand how climate change will affect the future spread of this potent vector, as an aidin assessing the risk of disease outbreaks and effectively allocating resources for vector control.

Methods: We used an empirically-informed, process-based mathematical model to study the feasibility of Aedes aegypti infestation into continental Europe. Based on established global climate-change scenario data, we assess the potential of Aedes aegypti to establish in Europe over the 21st century by estimating the vector population growth rate for five climate models (GCM5).

Results: In a low carbon emission future (RCP2.6), we find minimal change to the current situation throughout the whole of the 21st century. In a high carbon future (RCP8.5), a large parts of southern Europe risks being invaded by Aedes aegypti.

Conclusion: Our results show that successfully enforcing the Paris Agreement by limiting global warming to below 2 °C significantly lowers the risk for infestation of Aedes aegypti and consequently of potential large-scale arboviral disease outbreaks in Europe within the 21st century.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Aedes aegypti, Vector invasion, Europe, Climate change
National Category
Public Health, Global Health, Social Medicine and Epidemiology Climate Research
Identifiers
urn:nbn:se:umu:diva-143763 (URN)10.1016/j.envres.2019.02.026 (DOI)000468377500079 ()30884421 (PubMedID)
Funder
Swedish Research Council, 2015-03917Swedish Research Council Formas, 2017-01300
Note

Originally included in thesis in manuscript form with title "Climate change may enable Aedes aegypti mosquitoes infestation in major European cities by 2100"

Available from: 2018-01-09 Created: 2018-01-09 Last updated: 2019-06-20Bibliographically approved
Liu-Helmersson, J., Brännström, Å., Sewe, M. & Rocklöv, J. (2019). Estimating past, present and future trends in the global distribution and abundance of the arbovirus vector Aedes aegypti. Frontiers In Public Health, 7, Article ID 148.
Open this publication in new window or tab >>Estimating past, present and future trends in the global distribution and abundance of the arbovirus vector Aedes aegypti
2019 (English)In: Frontiers In Public Health, ISSN 2296-2565, Vol. 7, article id 148Article in journal (Other academic) Published
Abstract [en]

Background: Aedes aegypti is the principal vector for several important arbovirus diseases, including dengue, chikungunya, yellow fever, and Zika. While recent empirical research has attempted to identify the current global distribution of the vector, the seasonal, and longer-term dynamics of the mosquito in response to trends in climate, population, and economic development over the twentieth and the twenty-first century remains to be elucidated.

Methods: In this study, we use a process-based mathematical model to estimate global vector distribution and abundance. The model is based on the lifecycle of the vector and its dependence on climate, and the model sensitivity to socio-economic development is tested. Model parameters were generally empirically based, and the model was calibrated to global databases and time series of occurrence and abundance records. Climate data on temperature and rainfall were taken from CRU TS3.25 (1901–2015) and five global circulation models (CMIP5; 2006–2099) forced by a high-end (RCP8.5) and a low-end (RCP2.6) emission scenario. Socio-economic data on global GDP and human population density were from ISIMIP (1950–2099).

Findings: The change in the potential of global abundance in A. aegypti over the last century up to today is estimated to be an increase of 9.5% globally and a further increase of 20 or 30% by the end of this century under a low compared to a high carbon emission future, respectively. The largest increase has occurred in the last two decades, indicating a tipping point in climate-driven global abundance which will be stabilized at the earliest in the mid-twenty-first century. The realized abundance is estimated to be sensitive to socioeconomic development.

Interpretation: Our data indicate that climate change mitigation, i.e., following the Paris Agreement, could considerably help in suppressing risks of increased abundance and emergence of A. aegypti globally in the second half of the twenty-first century.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2019
Keywords
Aedes aegypti, mathematical model, vector abundance, temperature, precipitation, climate change, socioeconomic factors, global vector abundance
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-143762 (URN)10.3389/fpubh.2019.00148 (DOI)000472667800001 ()31249824 (PubMedID)
Funder
EU, Horizon 2020, 734584Swedish Research Council, 2015-03917Swedish Research Council Formas, 2017-01300
Note

Originally included in thesis in manuscript form.

Available from: 2018-01-09 Created: 2018-01-09 Last updated: 2019-07-22Bibliographically approved
Lillepold, K., Rocklöv, J., Liu-Helmersson, J., Sewe, M. & Semenza, J. C. (2019). More arboviral disease outbreaks in continental Europe due to the warming climate?. Journal of Travel Medicine
Open this publication in new window or tab >>More arboviral disease outbreaks in continental Europe due to the warming climate?
Show others...
2019 (English)In: Journal of Travel Medicine, ISSN 1195-1982, E-ISSN 1708-8305Article in journal (Refereed) Epub ahead of print
Place, publisher, year, edition, pages
Cary: Oxford University Press, 2019
Keywords
arbovirus infections, climate, disease outbreaks
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-158033 (URN)10.1093/jtm/taz017 (DOI)30850834 (PubMedID)
Available from: 2019-04-11 Created: 2019-04-11 Last updated: 2019-04-26
Sang, S., Liu-Helmersson, J., Quam, M. B. M., Zhou, H., Guo, X., Wu, H. & Liu, Q. (2019). The evolutionary dynamics of DENV 4 genotype I over a 60-year period. PLoS Neglected Tropical Diseases, 13(7), Article ID e0007592.
Open this publication in new window or tab >>The evolutionary dynamics of DENV 4 genotype I over a 60-year period
Show others...
2019 (English)In: PLoS Neglected Tropical Diseases, ISSN 1935-2727, E-ISSN 1935-2735, Vol. 13, no 7, article id e0007592Article in journal (Refereed) Published
Abstract [en]

Dengue virus serotype 4 (DENV 4) has had a relatively low prevalence worldwide for decades; however, likely due to data paucity, no study has investigated the epidemiology and evolutionary dynamics of DENV 4 genotype I (DENV 4-I). This study aims to understand the diversity, epidemiology and dynamics of DENV 4-I. We collected 404 full length DENV4-1 envelope (E) gene sequences from 14 countries using two sources: Yunnan Province in China (15 strains during 2013-2016) and GenBank (489 strains up to 2018-01-11). Conducting phylogenetic and phylogeographical analyses, we estimated the virus spread, population dynamics, and selection pressures using different statistical analysis methods (substitution saturation, likelihood mapping, Bayesian coalescent inference, and maximum likelihood estimation). Our results show that during the last 60 years (1956-2016), DENV 4-I was present in mainland and maritime Southeast Asia, the Indian subcontinent, the southern provinces of China, parts of Brazil and Australia. The recent spread of DENV 4-I likely originated in the Philippines and later spread to Thailand. From Thailand, it spread to adjacent countries and eventually the Indian subcontinent. Apparently diverging around years 1957, 1963, 1976 and 1990, the different Clades (Clade I-V) were defined. The mean overall evolution rate of DENV 4-I was 9.74 (95% HPD: 8.68-10.82) x 10(-4) nucleotide substitutions/site/year. The most recent common ancestor for DENV 4-I traces back to 1956. While the demographic history of DENV 4-I fluctuated, peaks appeared around 1982 and 2006. While purifying selection dominated the majority of E-gene evolution of DENV 4-I, positive selection characterized Clade III (Vietnam). DENV 4-I evolved in situ in Southeast Asia and the Indian subcontinent. Thailand and Indian acted as the main and secondary virus distribution hubs globally and regionally. Our phylogenetic analysis highlights the need for strengthened regional cooperation on surveillance and sharing of sample sequences to improve global dengue control and cross-border transmission prevention efforts. Author summary Dengue virus (DENV) can be classified into four serotypes, DENV 1, 2, 3 and 4. Although DENV 4 is the first dengue serotype to diverge in phylogenetic analyses of the genus Flavivirus, this serotype occurs at a low prevalence worldwide and spreads the least rapidly. Similar to other serotypes, DENV 4 can also cause severe dengue (SD) disease manifestations, such as dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). To date, no study has investigated the epidemiology and dynamics of DENV 4 genotype I comprehensively. In this study, we seek to address this gap. Our study shows that the distribution of DENV 4-I is mainly restricted to Southeast Asia and the Indian subcontinent. The most recent spread of DENV 4-I likely originated from Southeast Asia-initially circulating in the Philippines, then Thailand and later on the Indian subcontinent. Viruses evolved in situ in Southeast Asia and the Indian subcontinent, respectively. Although DENV 4-I occasionally spread elsewhere, this genotype did not become widely established. The overall evolution rate of DENV 4-I was comparable with that of DENV 2-4. The nucleotide sequences indicates that the demographic history of DENV 4-I fluctuated with peaks apparent during parts of the 1980s and 2000s. Although a weak positive selection existed in Clade III -predominately in Vietnam, purifying selection dominated the E-gene evolution of DENV 4-I.

Place, publisher, year, edition, pages
Public Library of Science, 2019
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-162684 (URN)10.1371/journal.pntd.0007592 (DOI)000478662500066 ()31356608 (PubMedID)
Available from: 2019-08-29 Created: 2019-08-29 Last updated: 2019-08-29Bibliographically approved
Liu-Helmersson, J. (2018). Climate Change, Dengue and Aedes Mosquitoes: Past Trends and Future Scenarios. (Doctoral dissertation). Umeå: Umeå universitet
Open this publication in new window or tab >>Climate Change, Dengue and Aedes Mosquitoes: Past Trends and Future Scenarios
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Background Climate change, global travel and trade have facilitated the spread of Aedes mosquitoes and have consequently enabled the diseases they transmit (dengue fever, Chikungunya, Zika and yellow fever) to emerge and re-emerge in uninfected areas. Large dengue outbreaks occurred in Athens in 1927 and in Portuguese island, Madeira in 2012, but there are almost no recent reports of Aedes aegypti, the principal vector, in Europe. A dengue outbreak needs four conditions: sufficient susceptible humans, abundant Aedes vector, dengue virus introduction, and conducive climate. Can Aedes aegypti establish themselves again in Europe in the near future if they are introduced? How do the current and future climate affect dengue transmission globally, and regionally as in Europe? This thesis tries to answer these questions.

Methods Two process-based mathematical models were developed in this thesis. Model 1 describes a vector’s ability to transmit dengue – vectorial capacity – based on temperature and diurnal temperature range (DTR). Model 2 describes vector population dynamics based on the lifecycle of Aedes aegypti. From this model, vector abundance was estimated using both climate as a single driver, and climate together with human population and GDP as multiple drivers; vector population growth rate was derived as a threshold condition to estimate the vector’s invasion to a new place.

Results Using vectorial capacity, we estimate dengue epidemic potential globally for Aedes aegypti and in Europe for Aedes aegypti and Aedes albopictus. We show that mean temperature and DTR are both important in modelling dengue transmission, especially in a temperate climate zone like Europe. Currently, South Europe is over the threshold for dengue epidemics if sufficient dengue vectors are present. Aedes aegypti is on the borderline of invasion into the southern tip of Europe. However, by end of this century, the invasion of Aedes aegypti may reach as far north as the middle of Europe under the business-as-usual climate scenario. Or it may be restricted to the south Europe from the middle of the century if the low carbon emission – Paris Agreement – is implemented to limit global warming to below 2°C.

Conclusion Climate change will increase the area and time window for Aedes aegypti’s invasion and consequently the dengue epidemic potential globally, and in Europe in particular. Successfully achieving the Paris Agreement would considerably change the future risk scenario of a highly competent vector – Aedes aegypti’s – invasion into Europe. Therefore, the risk of transmission of dengue and other infectious diseases to the mainland of Europe depends largely on human efforts to mitigate climate change.

Abstract [sv]

Bakgrund Klimatförändringar tillsammans med en ökad frekvens av globala resor och handel har gynnat spridningen av Aedes-myggor och möjliggjort att de sjukdomar som de överför (dengue feber, Chikungunya, Zika och gul feber) etablerar sig i tidigare oinfekterade områden. Det två största utbrotten av dengue i Europa inträffade i Aten 1927 och på den portugisiska ön Madeira 2012 orsakades av Aedes aegypti, men i de allra flesta delar i Europa finns inga rapporter om Aedes aegypti. Ett utbrott av dengue kräver att fyra villkor uppfylls: tillräckligt mottagliga människor, rikligt med Aedes-vektorer, introduktion av dengue-virus, och ett gynnsamt klimat. En stor fråga idag är om Aedes aegypti kan etableras igen i Europa i ett förändrat klimat, och hur nuvarande och framtida klimatförhållanden möjligör dengue smittspridning globalt och regionalt i Europa. Denna avhandling försöker svara på dessa frågor.

Metoder Två processbaserade matematiska modeller utvecklades i arbetet med denna avhandling. En av modellerna beskriver vektorns förmåga att överföra dengue – vektorkapaciteten – baserat på temperatur och dyngstemperaturens varation (DTR). Den andra modellen beskriver vektorpopulationens dynamik baserat på myggans livscykel. Myggornas populationsdynamik och populationstäthet uppskattades med en modell baserat på enbart klimat, samt en modell baserat på klimat, mänsklig befolkning och BNP. Vektorgruppens tillväxthastighet härleddes som ett tröskelvärde för att uppskatta vektorernas invasionsbenägenhet till nya områden i takt med att klimatet förändras.

Resultat Med hjälp av vektorkapacitetmodellen uppskattade vi den epidemiska potentialen av dengue smittad av Aedes aegypti globalt och i Europa av Aedes aegypti och Aedes albopictus. Vi visar att den genomsnittliga temperaturen och DTR båda är viktiga för dengue myggornas kapacitet att starta epidemier, särskilt i tempererade klimatzoner, så som Europa. För närvarande är Syd-Europa tillräckligt gynnsamt för dengueepidemier vissa tider på året om myggpopulationerna är tillräckligt stora. Vi visat att Aedes aegypti möjligen kan etablera sig längs Europas södra utkanter idag. I slutet av detta århundrade kan invasionen av Aedes aegypti nå så långt norrut till mitten av Europa om vi inte begränsar klimatutsläppen mer än vad vi gör idag. Om vi följer klimatavtalet från Paris 2015 där den globala uppvärmningen begränsar till under 2 grader kan invasionen troligtvis förhindras, eller i vilket fall kraftigt begränsas i Europa.

Slutsats Ett varmare klimat kommer att öka antalet geografiska områdena i Europa som är gynnsamt för Aedes aegypti. Det kommer även öka tidsfönstret för vektorernas epidemiska potential globalt, och i synnerhet för Europa. En framgångsrik implementering av klimatavtalet från 2015, som riktar sig mot att begränsa uppvärmingen till under 2 grader, skulle väsentligt minska risken för en framtida invasion av dengue, zika och chikungunya i Europa. Därför beror risken för dengueöverföring och andra infektionssjukdomar i södra Europa till stor del på mänskliga ansträngningar för att med utsläppsminskningar av växthusgaser kontrollera klimatförändringen.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2018. p. 100
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1931
Keywords
dengue, mathematical modelling, vectorial capacity, DTR, Aedes aegypti, Aedes albopictus, climate change, Europe, vector invasion, abundance, dengue, matematisk modellering, vektorkapacitet, DTR, Aedes aegypti, Aedes albopictus, klimatförändring, Europa, vektor invasion
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Research subject
Epidemiology
Identifiers
urn:nbn:se:umu:diva-143764 (URN)978-91-7601-798-2 (ISBN)
Public defence
2018-02-02, Hörsal D, Tandläkarhögskolan, By1D, 9 tr, Norrlands universitetssjukhus, Umeå, 09:00 (English)
Opponent
Supervisors
Available from: 2018-01-12 Created: 2018-01-09 Last updated: 2018-06-09Bibliographically approved
Massad, E., Amaku, M., Coutinho, F. A., Struchiner, C. J., Burattini, M. N., Khan, K., . . . Wilder-Smith, A. (2018). Estimating the probability of dengue virus introduction and secondary autochthonous cases in Europe. Scientific Reports, 8(1), Article ID 4629.
Open this publication in new window or tab >>Estimating the probability of dengue virus introduction and secondary autochthonous cases in Europe
Show others...
2018 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, no 1, article id 4629Article in journal (Refereed) Published
Abstract [en]

Given the speed of air travel, diseases even with a short viremia such as dengue can be easily exported to dengue naïve areas within 24 hours. We set out to estimate the risk of dengue virus introductions via travelers into Europe and number of secondary autochthonous cases as a result of the introduction. We applied mathematical modeling to estimate the number of dengue-viremic air passengers from 16 dengue-endemic countries to 27 European countries, taking into account the incidence of dengue in the exporting countries, travel volume and the probability of being viremic at the time of travel. Our models estimate a range from zero to 167 air passengers who are dengue-viremic at the time of travel from dengue endemic countries to each of the 27 receiving countries in one year. Germany receives the highest number of imported dengue-viremic air passengers followed by France and the United Kingdom. Our findings estimate 10 autochthonous secondary asymptomatic and symptomatic dengue infections, caused by the expected 124 infected travelers who arrived in Italy in 2012. The risk of onward transmission in Europe is reassuringly low, except where Aedes aegypti is present.

National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-147390 (URN)10.1038/s41598-018-22590-5 (DOI)000427465800009 ()29545610 (PubMedID)
Available from: 2018-05-02 Created: 2018-05-02 Last updated: 2018-06-09Bibliographically approved
Zhang, X., Wang, Y., Qu, P., Liu-Helmersson, J., Zhao, L., Zhang, L. & Sang, S. (2018). The Prognostic Value of Tumor Length for Cause-Specific Mortality in Resectable Esophageal Cancer.. Annals of Thoracic Surgery, 106(4), 1038-1046
Open this publication in new window or tab >>The Prognostic Value of Tumor Length for Cause-Specific Mortality in Resectable Esophageal Cancer.
Show others...
2018 (English)In: Annals of Thoracic Surgery, ISSN 0003-4975, E-ISSN 1552-6259, Vol. 106, no 4, p. 1038-1046Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: The current esophageal cancer AJCC-TNM staging system may not capture the full prognostic implications of the primary tumor. A study is needed to explore the prognostic value of tumor size on esophageal cancer-specific mortality.

METHODS: Patients who underwent surgical resection for non-metastatic esophageal cancer were selected from the Surveillance, Epidemiology and End Results Program database (United States, 1988 - 2014). Using statistics methods - maximally selected rank and two hazard models (Cox model and Fine-Gray model) - the optimum cutoff point for tumor length in each T classification was estimated and the prognostic value of tumor size on esophageal cancer-specific mortality was analyzed.

RESULTS: 4,447 patients were identified. The median tumor size was significantly correlated with T classification, with the correlation coefficient of 0.43 (p < 0.001). Patients in the T1-T3 classifications who had larger tumor size showed a larger probability of cancer-specific mortality. The multivariate Cox model showed that tumor size was significantly associated with an increase in cancer-specific mortality in T1 (2.15, 95% CI [1.72, 2.69]) and T2 (1.31, 95% CI [1.06, 1.62]), but marginally significantly in T3 (1.12, 95% CI [1.00, 1.27]) and insignificantly in T4 classification (p > 0.1). Similar results were found using the multivariate Fine-Gray model.

CONCLUSIONS: We have found that combining T classification with tumor size can increase the precision in identifying the high-risk groups in T1-T2 classification. Based on esophageal cancer-specific mortality our study is the first to explore the prognostic cutoff point of tumor size by T classification.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-150579 (URN)10.1016/j.athoracsur.2018.05.018 (DOI)000445116100033 ()29883640 (PubMedID)
Available from: 2018-08-13 Created: 2018-08-13 Last updated: 2018-10-05Bibliographically approved
Zhang, X., Wang, Y., Li, C., Helmersson, J., Jiang, Y., Ma, G., . . . Du, J. (2017). The prognostic value of tumor length to resectable esophageal squamous cell carcinoma: a retrospective study. PeerJ, 5, Article ID e2943.
Open this publication in new window or tab >>The prognostic value of tumor length to resectable esophageal squamous cell carcinoma: a retrospective study
Show others...
2017 (English)In: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 5, article id e2943Article in journal (Refereed) Published
Abstract [en]

Background: The current TNM classification system does not consider tumor length for patients with esophageal carcinoma (EC). This study explored the effect of tumor length, in addition to tumor depth and lymph node involvement, on survival in patients with esophageal squamous cell carcinoma (ESCC).

Methods: A total of 498 ESCC patients who underwent surgical resection as the primary treatment were selected in the retrospective study. Pathological details were collected, which included tumor type, TNM stage, differentiation. Other collected information were: the types of esophageal resection, ABO blood group, family history and demographic and lifestyle factors. A time-dependent receiver operating characteristic (ROC) curve and a regression tree for survival were used to identify the cut-off point of tumor length, which was 3 cm. Univariate and multivariate Cox proportional hazard regression models were used to identify the prognostic factors to ESCC.

Results & Discussion: The 1-, 3-, 5-year overall survival rates were found to be 82.5%, 55.6%, and 35.1%, respectively. Patients who had larger tumor length (>3 cm) had a higher risk for death than the rest patients. From the univariate Cox proportional hazards regression model, the overall survival rate was significantly influenced by the depth of the tumor and lymph node involvement (either as dummy or continuous variables), Sex, and tumor length. Using these four variables in the multivariate Cox proportional hazard regression model, we found that the overall survival was significantly influenced by all variables except Sex. Therefore, in addition to the depth of the tumor and lymph node involvement (as either dummy or continuous variables), the tumor length is also an independent prognostic factor for ESCC. The overall survival rate was higher in a group with smaller tumor length (≤3 cm) than those patients with larger tumor length (>3 cm), no matter what the tumor stage was.

Conclusion: The tumor length was found to be an important prognostic factor for ESCC patients without receiving neoadjuvant therapy. The modification of EC staging system may consider tumor length to better predict ESCC survival and identify higher risk patients for postoperative therapy.

Keywords
Esophageal squamous cell carcinoma, Prognostic factor, Long-term survival
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-133211 (URN)10.7717/peerj.2943 (DOI)000394708800006 ()28168111 (PubMedID)
Available from: 2017-04-13 Created: 2017-04-13 Last updated: 2018-06-09Bibliographically approved
Rocklöv, J., Quam, M. B., Sudre, B., German, M., Kraemer, M. U. .., Brady, O., . . . Khan, K. (2016). Assessing Seasonal Risks for the Introduction and Mosquito-borne Spread of Zika Virus in Europe. EBioMedicine, 9, 250-256
Open this publication in new window or tab >>Assessing Seasonal Risks for the Introduction and Mosquito-borne Spread of Zika Virus in Europe
Show others...
2016 (English)In: EBioMedicine, ISSN 0360-0637, E-ISSN 2352-3964, Vol. 9, p. 250-256Article in journal (Refereed) Published
Abstract [en]

The explosive Zika virus epidemic in the Americas is amplifying spread of this emerging pathogen into previously unaffected regions of the world, including Europe (Gulland, 2016), where local populations are immunologically naïve. As summertime approaches in the northern hemisphere, Aedes mosquitoes in Europe may find suitable climatic conditions to acquire and subsequently transmit Zika virus from viremic travellers to local populations. While Aedes albopictus has proven to be a vector for the transmission of dengue and chikungunya viruses in Europe (Delisle et al., 2015; ECDC, n.d.) there is growing experimental and ecological evidence to suggest that it may also be competent for Zika virus(Chouin-Carneiro et al., 2016; Grard et al., 2014; Li et al., 2012; Wong et al., 2013). Here we analyze and overlay the monthly flows of airline travellers arriving into European cities from Zika affected areas across the Americas, the predicted monthly estimates of the basic reproduction number of Zika virus in areas where Aedes mosquito populations reside in Europe (Aedes aegypti in Madeira, Portugal and Ae. albopictus in continental Europe), and human populations living within areas where mosquito-borne transmission of Zika virus may be possible. We highlight specific geographic areas and timing of risk for Zika virus introduction and possible spread within Europe to inform the efficient use of human disease surveillance, vector surveillance and control, and public education resources.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
ZIKV, Zika, Air travel, Globalization, mosquito, Climate, Aedes
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-122748 (URN)10.1016/j.ebiom.2016.06.009 (DOI)000381622500036 ()
Available from: 2016-06-21 Created: 2016-06-21 Last updated: 2018-06-07Bibliographically approved
Liu-Helmersson, J., Quam, M., Wilder-Smith, A., Stenlund, H., Ebi, K., Massad, E. & Rocklöv, J. (2016). Climate change and Aedes vectors: 21st century projections for dengue transmission in Europe. EBioMedicine, 7, 267-277
Open this publication in new window or tab >>Climate change and Aedes vectors: 21st century projections for dengue transmission in Europe
Show others...
2016 (English)In: EBioMedicine, ISSN 0360-0637, E-ISSN 2352-3964, Vol. 7, p. 267-277Article in journal (Refereed) Published
Abstract [en]

Warming temperatures may increase the geographic spread of vector-borne diseases into temperate areas. Although a tropical mosquito-borne viral disease, a dengue outbreak occurred in Madeira, Portugal, in 2012; the first in Europe since 1920s. This outbreak emphasizes the potential for dengue re-emergence in Europe given changing climates. We present estimates of dengue epidemic potential using vectorial capacity (VC) based on historic and projected temperature (1901–2099). VC indicates the vectors' ability to spread disease among humans. We calculated temperature-dependent VC for Europe, highlighting 10 European cities and three non-European reference cities. Compared with the tropics, Europe shows pronounced seasonality and geographical heterogeneity. Although low, VC during summer is currently sufficient for dengue outbreaks in Southern Europe to commence–if sufficient vector populations (either Ae. aegypti and Ae. albopictus) were active and virus were introduced. Under various climate change scenarios, the seasonal peak and time window for dengue epidemic potential increases during the 21st century. Our study maps dengue epidemic potential in Europe and identifies seasonal time windows when major cities are most conducive for dengue transmission from 1901 to 2099. Our findings illustrate, that besides vector control, mitigating greenhouse gas emissions crucially reduces the future epidemic potential of dengue in Europe.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Dengue, Vectorial capacity, Aedes aegypti, Aedes albopictus, Temperature, Climate change
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-118643 (URN)10.1016/j.ebiom.2016.03.046 (DOI)000377459700039 ()27322480 (PubMedID)
Funder
EU, FP7, Seventh Framework Programme, 282589
Note

This study is part of the DengueTools project funded by the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement no. 282589.

Originally included in thesis 1 as submitted manuscript.

Available from: 2016-03-28 Created: 2016-03-28 Last updated: 2018-06-07Bibliographically approved
Organisations

Search in DiVA

Show all publications