Can Human Movements Explain Heterogeneous Propagation of Dengue Fever in Cambodia?
- Publisher: Public Library of Science
PLoS Neglected Tropical Diseases,
(issn: 1935-2735, eissn: 1935-2735)
Research Article | Mathematics | Infectious Disease Control | Infectious Diseases | Infectious Disease Epidemiology | Epidemiology | Epidemiological Methods | Neglected Tropical Diseases | E51 - Population rurale | Disease Ecology | Public Health | Flavivirus | Biostatistics | http://aims.fao.org/aos/agrovoc/c_4073 | Medicine | Transmission des maladies | L73 - Maladies des animaux | RC955-962 | Dengue Fever | RA1-1270 | Public aspects of medicine | Genre humain | http://aims.fao.org/aos/agrovoc/c_2329 | Migration | http://aims.fao.org/aos/agrovoc/c_4822 | http://aims.fao.org/aos/agrovoc/c_2963 | Arctic medicine. Tropical medicine | Statistics | http://aims.fao.org/aos/agrovoc/c_4586
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. (Résumé d'auteur)