The dynamics of dengue virus serotype 3 introduction and dispersion in the state of Bahia, Brazil.
By 2002, dengue virus serotype 1 (DENV-1) and DENV-2 had circulated for more than a decade in Brazil. In 2002, the introduction of DENV-3 in the state of Bahia produced a massive epidemic and the first cases of dengue hemorrhagic fever. Based on the standardized frequency, timing and location of viral isolations by the state's Central Laboratory, DENV-3 probably entered Bahia through its capital, Salvador, and then rapidly disseminated to other cities, following the main roads. A linear regression model that included traffic flow, distance from the capital and DENV-1 circulation (r2 = 0.24, p = 0.001) supported this hypothesis. This pattern was not seen for serotypes already in circulation and was not seen for DENV-3 in the following year. Human population density was another important factor in the intensity of viral circulation. Neither DENV-1 nor DENV-2 fit this model for 2001 or 2003. Since the vector has limited flight range and vector densities fail to correlate with intensity of viral circulation, this distribution represents the movement of infected people and to some extent mosquitoes. This pattern may mimic person-to-person spread of a new infection.
Melo
Paulo Roberto Santana de
PR
Centro de Pesquisa Gonçalo Moniz, Fiocruz, 40295-001 Salvador, BA, Brasil.
Reis
Eliana Almeida Gomes
EA
Ciuffo
Isolina Allen
IA
Góes
Mônica
M
Blanton
Ronald Edward
RE
Reis
Mitermayer Galvão dos
MG
D001938:Brazil / Q000453:epidemiology; D003715:Dengue / Q000453:epidemiology / Q000821:virology*; D003716:Dengue Virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005843:Geography; D006801:Humans; D016014:Linear Models; D015999:Multivariate Analysis; D012703:Serotyping