Risk factors for dengue virus infection in rural Amazonia: population-based cross-sectional surveys.
A comparison of dengue virus (DENV) antibody levels in paired serum samples collected from predominantly DENV-naive residents in an agricultural settlement in Brazilian Amazonia (baseline seroprevalence, 18.3%) showed a seroconversion rate of 3.67 episodes/100 person-years at risk during 12 months of follow-up. Multivariate analysis identified male sex, poverty, and migration from extra-Amazonian states as significant predictors of baseline DENV seropositivity, whereas male sex, a history of clinical diagnosis of dengue fever, and travel to an urban area predicted subsequent seroconversion. The laboratory surveillance of acute febrile illnesses implemented at the study site and in a nearby town between 2004 and 2006 confirmed 11 DENV infections among 102 episodes studied with DENV IgM detection, reverse transcriptase-polymerase chain reaction, and virus isolation; DENV-3 was isolated. Because DENV exposure is associated with migration or travel, personal protection measures when visiting high-risk urban areas may reduce the incidence of DENV infection in this rural population.
da Silva-Nunes
Mônica
M
Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil. msnunes1@yahoo.com.br
de Souza
Vanda A F
VA
Pannuti
Cláudio S
CS
Sperança
Márcia A
MA
Terzian
Ana Carolina B
AC
Nogueira
Maurício L
ML
Yamamura
Anna M Y
AM
Freire
Marcos S
MS
da Silva
Natal S
NS
Malafronte
Rosely S
RS
Muniz
Pascoal T
PT
Vasconcelos
Helena B
HB
da Silva
Eliana V P
EV
Vasconcelos
Pedro F C
PF
Ferreira
Marcelo U
MU
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003715:Dengue / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012727:Sex Characteristics
D000914:Antibodies, Viral; D007075:Immunoglobulin M