Fine Scale Spatiotemporal Clustering of Dengue Virus Transmission in Children and Aedes aegypti in Rural Thai Villages

Authors

In-Kyu Yoon
Arthur Getis
Jared Aldstadt
Alan L. Rothman, University of Rhode IslandFollow
Darunee Tannitisupawong
Constantianus J.M. Koenraadt
Thanyalak Fansiri
James W. Jones
Amy C. Morrison
Richard G. Jarmen
Ananda Nisalak
Mammen P. Mammen Jr.
Suwich Thammapalo
Anon Srikiatkhachorn
Sharone Green
Daniel H. Libraty
Robert V. Gibbons
Timothy Endy
Chusak Pimgate
Thomas W. Scott

Document Type

Article

Date of Original Version

7-17-2012

Abstract

Background: Based on spatiotemporal clustering of human dengue virus (DENV) infections, transmission is thought to occur at fine spatiotemporal scales by horizontal transfer of virus between humans and mosquito vectors. To define the dimensions of local transmission and quantify the factors that support it, we examined relationships between infected humans and Aedes aegypti in Thai villages.

Methodology/Principal Findings: Geographic cluster investigations of 100-meter radius were conducted around DENV-positive and DENV-negative febrile ‘‘index’’ cases (positive and negative clusters, respectively) from a longitudinal cohort study in rural Thailand. Child contacts and Ae. aegypti from cluster houses were assessed for DENV infection. Spatiotemporal, demographic, and entomological parameters were evaluated. In positive clusters, the DENV infection rate among child contacts was 35.3% in index houses, 29.9% in houses within 20 meters, and decreased with distance from the index house to 6.2% in houses 80–100 meters away (pAe. aegypti were DENV-infectious (i.e., DENV-positive in head/thorax) in positive clusters (23/1755; 1.3%) than negative clusters (1/1548; 0.1%). In positive clusters, 8.2% of mosquitoes were DENV-infectious in index houses, 4.2% in other houses with DENV-infected children, and 0.4% in houses without infected children (pAe. aegypti pupae and adult females were more numerous only in houses containing infectious mosquitoes.

Conclusions/Significance: Human and mosquito infections are positively associated at the level of individual houses and neighboring residences. Certain houses with high transmission risk contribute disproportionately to DENV spread to neighboring houses. Small groups of houses with elevated transmission risk are consistent with over-dispersion of transmission (i.e., at a given point in time, people/mosquitoes from a small portion of houses are responsible for the majority of transmission).

Citation/Publisher Attribution

Yoon, I-K., Getis, A., Aldstadt, J., Rothman, A. L., Tannitisupawong, D., et al. (2012). Fine Scale Spatiotemporal Clustering of Dengue Virus Transmission in Children and Aedes aegypti in Rural Thai Villages. PLoS Neglected Tropical Diseases, 6(7): e1730.

Available at: http://dx.doi.org/10.1371/journal.pntd.0001730

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