title: Revisiting Rayong: shifting seroprofiles of dengue in Thailand and their implications for transmission and control.
abstract: Dengue virus has traditionally caused substantial morbidity and mortality among children less than 15 years of age in Southeast Asia. Over the last 2 decades, a significant increase in the mean age of cases has been reported, and a once pediatric disease now causes substantial burden among the adult population. An age-stratified serological study (n = 1,736) was conducted in 2010 among schoolchildren in the Mueang Rayong district of Thailand, where a similar study had been conducted in 1980/1981. Serotype-specific forces of infection (λ(t)) and basic reproductive numbers (R0) of dengue were estimated for the periods 1969-1980 and 1993-2010. Despite a significant increase in the age at exposure and a decrease in λ(t) from 0.038/year to 0.019/year, R0 changed only from 3.3 to 3.2. Significant heterogeneity was observed across subdistricts and schools, with R0 ranging between 1.7 and 6.8. These findings are consistent with the idea that the observed age shift might be a consequence of the demographic transition in Thailand. Changes in critical vaccination fractions, estimated by using R0, have not accompanied the increase in age at exposure. These results have implications for dengue control interventions because multiple countries in Southeast Asia are undergoing similar demographic transitions. It is likely that dengue will never again be a disease exclusively of children.
authors.forename: Isabel
authors.initials: I
authors.lastname: Rodríguez-Barraquer
authors.forename: Rome
authors.initials: R
authors.lastname: Buathong
authors.forename: Sopon
authors.initials: S
authors.lastname: Iamsirithaworn
authors.forename: Ananda
authors.initials: A
authors.lastname: Nisalak
authors.forename: Justin
authors.initials: J
authors.lastname: Lessler
authors.forename: Richard G
authors.initials: RG
authors.lastname: Jarman
authors.forename: Robert V
authors.initials: RV
authors.lastname: Gibbons
authors.forename: Derek A T
authors.initials: DA
authors.lastname: Cummings
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000914:Antibodies, Viral / Q000097:blood; D050936:Basic Reproduction Number; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003715:Dengue / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D003716:Dengue Virus / Q000276:immunology; D006306:Health Surveys; D006801:Humans; D007223:Infant; D015233:Models, Statistical; D016036:Seroepidemiologic Studies; D013785:Thailand / Q000453:epidemiology; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D015415:Biomarkers
keywords: basic reproductive number; critical vaccination fraction; demography; dengue; force of infection; transmission dynamics