Air travel is associated with intracontinental spread of dengue virus serotypes 1-3 in Brazil.
Nunes MR., Palacios G., Faria NR., Sousa EC., Pantoja JA., Rodrigues SG., Carvalho VL., Medeiros DB., Savji N., Baele G., Suchard MA., Lemey P., Vasconcelos PF., Lipkin WI.
Dengue virus and its four serotypes (DENV-1 to DENV-4) infect 390 million people and are implicated in at least 25,000 deaths annually, with the largest disease burden in tropical and subtropical regions. We investigated the spatial dynamics of DENV-1, DENV-2 and DENV-3 in Brazil by applying a statistical framework to complete genome sequences. For all three serotypes, we estimated that the introduction of new lineages occurred within 7 to 10-year intervals. New lineages were most likely to be imported from the Caribbean region to the North and Northeast regions of Brazil, and then to disperse at a rate of approximately 0.5 km/day. Joint statistical analysis of evolutionary, epidemiological and ecological data indicates that aerial transportation of humans and/or vector mosquitoes, rather than Aedes aegypti infestation rates or geographical distances, determine dengue virus spread in Brazil.