Can human movements explain heterogeneous propagation of dengue fever in Cambodia?

• Published in: PLoS Neglected Tropical Diseases
• Main Authors: Magali Teurlai, Rekol Huy, Bernard Cazelles, Raphaël Duboz, Christophe Baehr, Sirenda Vong
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2012
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic
• Online Access: https://doi.org/10.1371/journal.pntd.0001957; https://doaj.org/article/364423dac050466e8fa745d8da0e7bd6

BACKGROUND: Determining the factors underlying the long-range spatial spread of infectious diseases is a key issue regarding their control. Dengue is the most important arboviral disease worldwide and a major public health problem in tropical areas. However the determinants shaping its dynamics at a national scale remain poorly understood. Here we describe the spatial-temporal pattern of propagation of annual epidemics in Cambodia and discuss the role that human movements play in the observed pattern. METHODS AND FINDINGS: We used wavelet phase analysis to analyse time-series data of 105,598 hospitalized cases reported between 2002 and 2008 in the 135 (/180) most populous districts in Cambodia. We reveal spatial heterogeneity in the propagation of the annual epidemic. Each year, epidemics are highly synchronous over a large geographic area along the busiest national road of the country whereas travelling waves emanate from a few rural areas and move slowly along the Mekong River at a speed of ~11 km per week (95% confidence interval 3-18 km per week) towards the capital, Phnom Penh. CONCLUSIONS: We suggest human movements - using roads as a surrogate - play a major role in the spread of dengue fever at a national scale. These findings constitute a new starting point in the understanding of the processes driving dengue spread.