title: Index cluster study of dengue virus infection in Nicaragua.
abstract: Traditional study designs do not identify acute asymptomatic or pre-symptomatic dengue virus (DENV) infections, thus limiting our understanding of immunologic and viral factors that modulate infection outcome. In the 2006 and 2007 dengue seasons, we conducted a pilot index cluster study in Managua, Nicaragua, in which 442 persons living within 50 meters of 22 index cases identified through an ongoing pediatric cohort study were evaluated for DENV infection. Post-enrollment and pre-enrollment DENV infections were confirmed in 12 (2.7%) and 19 (4.3%) contacts, respectively. Five (42%) post-enrollment infections were asymptomatic, and DENV-2 was identified in 9 (75%) infections. Phylogenetic analysis with full-length DENV genomic sequence from contacts, index cases, and cohort dengue cases indicated focal transmission and infection outside the local area. We demonstrate the feasibility of identification of acute asymptomatic and pre-symptomatic cases in urban Latin America, the first report of such a study in the Americas, and identify age and concomitant immunity to DENV of contacts as a key factor in index cluster study design.
authors.affiliation: Socrates Flores Vivas Health Center, Ministry of Health, Managua, Nicaragua.
authors.forename: Miguel
authors.initials: M
authors.lastname: Reyes
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Mercado
authors.forename: Katherine
authors.initials: K
authors.lastname: Standish
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Matute
authors.forename: Oscar
authors.initials: O
authors.lastname: Ortega
authors.forename: Berman
authors.initials: B
authors.lastname: Moraga
authors.forename: William
authors.initials: W
authors.lastname: Avilés
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Henn
authors.forename: Angel
authors.initials: A
authors.lastname: Balmaseda
authors.forename: Guillermina
authors.initials: G
authors.lastname: Kuan
authors.forename: Eva
authors.initials: E
authors.lastname: Harris
mesh_terms: D000293:Adolescent; D001483:Base Sequence; D016000:Cluster Analysis; D017931:DNA Primers; D003715:Dengue / Q000453:epidemiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D009527:Nicaragua / Q000453:epidemiology; D010802:Phylogeny
chemical_list: D017931:DNA Primers
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