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. 2018 Nov 9;12(11):e0006743.
doi: 10.1371/journal.pntd.0006743. eCollection 2018 Nov.

Seasonal and interannual risks of dengue introduction from South-East Asia into China, 2005-2015

Affiliations

Seasonal and interannual risks of dengue introduction from South-East Asia into China, 2005-2015

Shengjie Lai et al. PLoS Negl Trop Dis. .

Abstract

Due to worldwide increased human mobility, air-transportation data and mathematical models have been widely used to measure risks of global dispersal of pathogens. However, the seasonal and interannual risks of pathogens importation and onward transmission from endemic countries have rarely been quantified and validated. We constructed a modelling framework, integrating air travel, epidemiological, demographical, entomological and meteorological data, to measure the seasonal probability of dengue introduction from endemic countries. This framework has been applied retrospectively to elucidate spatiotemporal patterns and increasing seasonal risk of dengue importation from South-East Asia into China via air travel in multiple populations, Chinese travelers and local residents, over a decade of 2005-15. We found that the volume of airline travelers from South-East Asia into China has quadrupled from 2005 to 2015 with Chinese travelers increased rapidly. Following the growth of air traffic, the probability of dengue importation from South-East Asia into China has increased dramatically from 2005 to 2015. This study also revealed seasonal asymmetries of transmission routes: Sri Lanka and Maldives have emerged as origins; neglected cities at central and coastal China have been increasingly vulnerable to dengue importation and onward transmission. Compared to the monthly occurrence of dengue reported in China, our model performed robustly for importation and onward transmission risk estimates. The approach and evidence could facilitate to understand and mitigate the changing seasonal threat of arbovirus from endemic regions.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Airline travelers and dengue importation from South-East Asia into China, 2005–2015.
(A) Yearly volume of airline travelers vs number of dengue cases imported from SEA into China. (B) Airline travelers vs dengue cases imported from SEA into China, aggregated by country.
Fig 2
Fig 2. Relative seasonal variation in monthly dengue incidence for SEA countries and China, sorted by latitude, 2005–2015.
(A) Time series of monthly dengue cases, standardized by the total number of cases reported in each year and country. (B) Average seasonal distribution of dengue by country, plotted as the proportion of cases reported in each week of the year from 2005 to 2015. The data of "China–import" represents the cases imported from nine SEA countries (Cambodia, Laos, Malaysia, Maldives, Philippines, Singapore, Sri Lanka, Thailand, and Vietnam) into China. The data of "China–local" represents the autochthonous cases reported in China.
Fig 3
Fig 3. Dengue importation and introduced transmission risks from South-East Asia into provinces of mainland China, 2005–2015.
(A) Importation risk by year. (B) Importation risk by month. (C) Introduced transmission risk by year. (D) Introduced transmission risk by month. The probabilistic risk presented here is the likelihood of occurrence of at least one DENV infection at provincial level. Nine countries (Cambodia, Laos, Malaysia, Maldives, Philippines, Singapore, Sri Lanka, Thailand, Vietnam) in SEA with available data of monthly DENV incidence were included here.
Fig 4
Fig 4. Geographic risks of dengue importation and introduced transmission from South-East Asia into cities of mainland China in 2005 and 2015.
The probabilistic risks (0–1) were estimates for travelers from nine SEA countries (Cambodia, Laos, Malaysia, Maldives, Philippines, Singapore, Sri Lanka, Thailand, and Vietnam) into 165 cities in China.
Fig 5
Fig 5. Origin-destination routes of dengue importation from SEA into top 20 high-risk cities of China in 2005 and 2015.
For 2005 (A) and 2015 (B), the lines indicate the most likely routes of DENV importation with thickness scaled to the estimate importation risk from the lowest (thinnest) to highest (thickest) for each panel. The numbers on the left indicate the average monthly probability of exporting at least one infected case from each origin to any of the cities of China and the numbers on the right, the average monthly probability of importation to each destination.
Fig 6
Fig 6. Estimates of imported DENV infections from nine SEA countries into China, 2005–2015.
(A) Time series of estimated infections in airline travelers, with 95% UI of estimates, and the reported cases imported from SEA. (B) Estimated infections vs reported cases by year. (C) Estimated infections vs reported cases by country. We estimated all symptomatic and asymptomatic infections that can possibly introduce transmission. In (B) and (C), symbol size is proportional to the volume of travelers from SEA into China, and blue solid lines represent linear regression fit, with p values and adjusted R-square values on the graphs.

References

    1. Tatem AJ, Hay SI, Rogers DJ. Global traffic and disease vector dispersal. Proc Natl Acad Sci U S A. 2006;103(16):6242–7. 10.1073/pnas.0508391103 . - DOI - PMC - PubMed
    1. Wang L, Wu JT. Characterizing the dynamics underlying global spread of epidemics. Nat Commun. 2018;9(1):218 10.1038/s41467-017-02344-z . - DOI - PMC - PubMed
    1. Morse SS. Factors in the emergence of infectious diseases. Emerg Infect Dis. 1995;1(1):7–15. 10.3201/eid0101.950102 . - DOI - PMC - PubMed
    1. Fidler DP. Globalization, international law, and emerging infectious diseases. Emerg Infect Dis. 1996;2(2):77–84. 10.3201/eid0202.960201 . - DOI - PMC - PubMed
    1. Stoddard ST, Morrison AC, Vazquez-Prokopec GM, Paz Soldan V, Kochel TJ, Kitron U, et al. The role of human movement in the transmission of vector-borne pathogens. PLoS Negl Trop Dis. 2009;3(7):e481 10.1371/journal.pntd.0000481 . - DOI - PMC - PubMed

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