Limits...
International dispersal of dengue through air travel: importation risk for Europe.

Semenza JC, Sudre B, Miniota J, Rossi M, Hu W, Kossowsky D, Suk JE, Van Bortel W, Khan K - PLoS Negl Trop Dis (2014)

Bottom Line: In fact, 38% more travellers arrived in 2013 into those parts of Europe where Ae. albopictus has recently been introduced, compared to 2010.The presence of the vector is a necessary, but not sufficient, prerequisite for DENV onward transmission, which depends on a number of additional factors.However, our empirical model can provide spatio-temporal elements to public health interventions.

View Article: PubMed Central - PubMed

Affiliation: European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.

ABSTRACT

Background: The worldwide distribution of dengue is expanding, in part due to globalized traffic and trade. Aedes albopictus is a competent vector for dengue viruses (DENV) and is now established in numerous regions of Europe. Viremic travellers arriving in Europe from dengue-affected areas of the world can become catalysts of local outbreaks in Europe. Local dengue transmission in Europe is extremely rare, and the last outbreak occurred in 1927-28 in Greece. However, autochthonous transmission was reported from France in September 2010, and from Croatia between August and October 2010.

Methodology: We compiled data on areas affected by dengue in 2010 from web resources and surveillance reports, and collected national dengue importation data. We developed a hierarchical regression model to quantify the relationship between the number of reported dengue cases imported into Europe and the volume of airline travellers arriving from dengue-affected areas internationally.

Principal findings: In 2010, over 5.8 million airline travellers entered Europe from dengue-affected areas worldwide, of which 703,396 arrived at 36 airports situated in areas where Ae. albopictus has been recorded. The adjusted incidence rate ratio for imported dengue into European countries was 1.09 (95% CI: 1.01-1.17) for every increase of 10,000 travellers; in August, September, and October the rate ratios were 1.70 (95%CI: 1.23-2.35), 1.46 (95%CI: 1.02-2.10), and 1.35 (95%CI: 1.01-1.81), respectively. Two Italian cities where the vector is present received over 50% of all travellers from dengue-affected areas, yet with the continuing vector expansion more cities will be implicated in the future. In fact, 38% more travellers arrived in 2013 into those parts of Europe where Ae. albopictus has recently been introduced, compared to 2010.

Conclusions: The highest risk of dengue importation in 2010 was restricted to three months and can be ranked according to arriving traveller volume from dengue-affected areas into cities where the vector is present. The presence of the vector is a necessary, but not sufficient, prerequisite for DENV onward transmission, which depends on a number of additional factors. However, our empirical model can provide spatio-temporal elements to public health interventions.

No MeSH data available.


Related in: MedlinePlus

Passenger volume of outbound flights to Europe from dengue active areas (endemic and epidemic) at the city level by quarter, 2010.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4256202&req=5

pntd-0003278-g002: Passenger volume of outbound flights to Europe from dengue active areas (endemic and epidemic) at the city level by quarter, 2010.

Mentions: More than 5.8 million travellers entered Europe from dengue-affected areas in 2010 (figure 2 and 3); country-level arrival by month is shown in figure 4. Of the total number of travellers from dengue-affected areas, 30.7% originated from East Asia, 13.8% from South Asia, 9.5% from North Africa and West Asia, 16.7% from Sub-Saharan Africa, 0.9% from Eastern Europe and Central Asia, 14.2% from South America, 14.1% from Mexico, Central America and the Caribbean, and 0.2% from Australia and the Pacific Islands. The monthly average volume of international arrivals from dengue-affected areas for the third quarter was 228,000 for the UK; 213,000 for France; 110,000 for Germany; 80,000 for Italy; 42,000 for the Netherlands; 43,000 for Spain, and 19,000 for Sweden. At the peak of the Ae. albopictus mosquito season for Southern Europe, which are the summer months [12]–[14], traveller arrivals from dengue-affected areas remained high (figure 4), representing around 10% of the overall number of air travellers coming into Europe. We mapped the final European destinations and corresponding volumes of global air travellers arriving from areas with dengue activity during 2010 along with the European spatial extent of Ae. albopictus (figure 5). The biggest increase in traveller volume was seen in the third quarter when vector populations are at the peak. Of the 442 airports in Europe, 42 were within the area of Ae. albopictus activity in 2010, and 36 of these airports received travellers from dengue-affected areas. The maps also display areas where Ae. albopictus is present and thus DENV transmission could occur. Accordingly, southern European areas are at greatest risk for autochthonous dengue outbreaks. While the presence of the vector is a necessary but not sufficient prerequisite for DENV onward transmission, a number of factors such as vector density, human exposure, access to care, etc. are also important in determining the risk of autochthonous transmission.


International dispersal of dengue through air travel: importation risk for Europe.

Semenza JC, Sudre B, Miniota J, Rossi M, Hu W, Kossowsky D, Suk JE, Van Bortel W, Khan K - PLoS Negl Trop Dis (2014)

Passenger volume of outbound flights to Europe from dengue active areas (endemic and epidemic) at the city level by quarter, 2010.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4256202&req=5

pntd-0003278-g002: Passenger volume of outbound flights to Europe from dengue active areas (endemic and epidemic) at the city level by quarter, 2010.
Mentions: More than 5.8 million travellers entered Europe from dengue-affected areas in 2010 (figure 2 and 3); country-level arrival by month is shown in figure 4. Of the total number of travellers from dengue-affected areas, 30.7% originated from East Asia, 13.8% from South Asia, 9.5% from North Africa and West Asia, 16.7% from Sub-Saharan Africa, 0.9% from Eastern Europe and Central Asia, 14.2% from South America, 14.1% from Mexico, Central America and the Caribbean, and 0.2% from Australia and the Pacific Islands. The monthly average volume of international arrivals from dengue-affected areas for the third quarter was 228,000 for the UK; 213,000 for France; 110,000 for Germany; 80,000 for Italy; 42,000 for the Netherlands; 43,000 for Spain, and 19,000 for Sweden. At the peak of the Ae. albopictus mosquito season for Southern Europe, which are the summer months [12]–[14], traveller arrivals from dengue-affected areas remained high (figure 4), representing around 10% of the overall number of air travellers coming into Europe. We mapped the final European destinations and corresponding volumes of global air travellers arriving from areas with dengue activity during 2010 along with the European spatial extent of Ae. albopictus (figure 5). The biggest increase in traveller volume was seen in the third quarter when vector populations are at the peak. Of the 442 airports in Europe, 42 were within the area of Ae. albopictus activity in 2010, and 36 of these airports received travellers from dengue-affected areas. The maps also display areas where Ae. albopictus is present and thus DENV transmission could occur. Accordingly, southern European areas are at greatest risk for autochthonous dengue outbreaks. While the presence of the vector is a necessary but not sufficient prerequisite for DENV onward transmission, a number of factors such as vector density, human exposure, access to care, etc. are also important in determining the risk of autochthonous transmission.

Bottom Line: In fact, 38% more travellers arrived in 2013 into those parts of Europe where Ae. albopictus has recently been introduced, compared to 2010.The presence of the vector is a necessary, but not sufficient, prerequisite for DENV onward transmission, which depends on a number of additional factors.However, our empirical model can provide spatio-temporal elements to public health interventions.

View Article: PubMed Central - PubMed

Affiliation: European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.

ABSTRACT

Background: The worldwide distribution of dengue is expanding, in part due to globalized traffic and trade. Aedes albopictus is a competent vector for dengue viruses (DENV) and is now established in numerous regions of Europe. Viremic travellers arriving in Europe from dengue-affected areas of the world can become catalysts of local outbreaks in Europe. Local dengue transmission in Europe is extremely rare, and the last outbreak occurred in 1927-28 in Greece. However, autochthonous transmission was reported from France in September 2010, and from Croatia between August and October 2010.

Methodology: We compiled data on areas affected by dengue in 2010 from web resources and surveillance reports, and collected national dengue importation data. We developed a hierarchical regression model to quantify the relationship between the number of reported dengue cases imported into Europe and the volume of airline travellers arriving from dengue-affected areas internationally.

Principal findings: In 2010, over 5.8 million airline travellers entered Europe from dengue-affected areas worldwide, of which 703,396 arrived at 36 airports situated in areas where Ae. albopictus has been recorded. The adjusted incidence rate ratio for imported dengue into European countries was 1.09 (95% CI: 1.01-1.17) for every increase of 10,000 travellers; in August, September, and October the rate ratios were 1.70 (95%CI: 1.23-2.35), 1.46 (95%CI: 1.02-2.10), and 1.35 (95%CI: 1.01-1.81), respectively. Two Italian cities where the vector is present received over 50% of all travellers from dengue-affected areas, yet with the continuing vector expansion more cities will be implicated in the future. In fact, 38% more travellers arrived in 2013 into those parts of Europe where Ae. albopictus has recently been introduced, compared to 2010.

Conclusions: The highest risk of dengue importation in 2010 was restricted to three months and can be ranked according to arriving traveller volume from dengue-affected areas into cities where the vector is present. The presence of the vector is a necessary, but not sufficient, prerequisite for DENV onward transmission, which depends on a number of additional factors. However, our empirical model can provide spatio-temporal elements to public health interventions.

No MeSH data available.


Related in: MedlinePlus