UMMS Affiliation

Center for Infectious Disease and Vaccine Research; Department of Medicine, Division of Infectious Diseases and Immunology

Publication Date

9-11-2014

Document Type

Article

Disciplines

Epidemiology | Immunology of Infectious Disease | International Public Health | Virus Diseases | Viruses

Abstract

BACKGROUND: Dengue is endemic to the rural province of Kamphaeng Phet, Northern Thailand. A decade of prospective cohort studies has provided important insights into the dengue viruses and their generated disease. However, as elsewhere, spatial dynamics of the pathogen remain poorly understood. In particular, the spatial scale of transmission and the scale of clustering are poorly characterized. This information is critical for effective deployment of spatially targeted interventions and for understanding the mechanisms that drive the dispersal of the virus.

METHODOLOGY/PRINCIPAL FINDINGS: We geocoded the home locations of 4,768 confirmed dengue cases admitted to the main hospital in Kamphaeng Phet province between 1994 and 2008. We used the phi clustering statistic to characterize short-term spatial dependence between cases. Further, to see if clustering of cases led to similar temporal patterns of disease across villages, we calculated the correlation in the long-term epidemic curves between communities. We found that cases were 2.9 times (95% confidence interval 2.7-3.2) more likely to live in the same village and be infected within the same month than expected given the underlying spatial and temporal distribution of cases. This fell to 1.4 times (1.2-1.7) for individuals living in villages 1 km apart. Significant clustering was observed up to 5 km. We found a steadily decreasing trend in the correlation in epidemics curves by distance: communities separated by up to 5 km had a mean correlation of 0.28 falling to 0.16 for communities separated between 20 km and 25 km. A potential explanation for these patterns is a role for human movement in spreading the pathogen between communities. Gravity style models, which attempt to capture population movement, outperformed competing models in describing the observed correlations.

CONCLUSIONS: There exists significant short-term clustering of cases within individual villages. Effective spatially and temporally targeted interventions deployed within villages may target ongoing transmission and reduce infection risk.

Rights and Permissions

Citation: PLoS Negl Trop Dis. 2014 Sep 11;8(9):e3138. doi: 10.1371/journal.pntd.0003138. eCollection 2014. Link to article on publisher's site

DOI of Published Version

10.1371/journal.pntd.0003138

Comments

This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

PLoS neglected tropical diseases

PubMed ID

25211127

 
 

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