title: Epidemiology of Infant Dengue Cases Illuminates Serotype-Specificity in the Interaction between Immunity and Disease, and Changes in Transmission Dynamics.
abstract: BACKGROUND
  Infants born to dengue immune mothers acquire maternal antibodies to dengue. These antibodies, though initially protective, decline during the first year of life to levels thought to be disease enhancing, before reaching undetectable levels. Infants have long been studied to understand the interaction between infection and disease on an individual level.
  
  
  RESULTS
  Considering infants (cases <1 year old) as a unique group, we analyzed serotype specific dengue case data from patients admitted to a pediatric hospital in Bangkok, Thailand. We show differences in the propensity of serotypes to cause disease in individuals with dengue antibodies (infants and post-primary cases) and in individuals without dengue antibodies (primary cases). The mean age of infant cases differed among serotypes, consistent with previously observed differential waning of maternal antibody titers by serotype. We show that trends over time in epidemiology of infant cases are consistent with those observed in the whole population, and therefore with trends in the force of infection.
  
  
  CONCLUSIONS
  Infants with dengue are informative about the interaction between antibody and the dengue serotypes, confirming that in this population DENV-2 and DENV-4 almost exclusively cause disease in the presence of dengue antibody despite infections occurring in others. We also observe differences between the serotypes in the mean age in infant cases, informative about the interaction between waning immunity and disease for the different serotypes in infants. In addition, we show that the mean age of infant cases over time is informative about transmission in the whole population. Therefore, ongoing surveillance for dengue in infants could provide useful insights into dengue epidemiology, particularly after the introduction of a dengue vaccine targeting adults and older children.
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Hannah
authors.initials: H
authors.lastname: Clapham
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland, United States of America.|Department of Biology, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Derek A T
authors.initials: DA
authors.lastname: Cummings
authors.affiliation: Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors.forename: Ananda
authors.initials: A
authors.lastname: Nisalak
authors.affiliation: Queen Sirikit National Institute of Child Health, Bangkok, Thailand.
authors.forename: Siripen
authors.initials: S
authors.lastname: Kalayanarooj
authors.affiliation: Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors.forename: Butsaya
authors.initials: B
authors.lastname: Thaisomboonsuk
authors.affiliation: Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors.forename: Chonticha
authors.initials: C
authors.lastname: Klungthong
authors.affiliation: Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fernandez
authors.affiliation: Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
authors.forename: Anon
authors.initials: A
authors.lastname: Srikiatkhachorn
authors.affiliation: Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors.forename: Louis R
authors.initials: LR
authors.lastname: Macareo
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Justin
authors.initials: J
authors.lastname: Lessler
authors.affiliation: Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors.forename: Julia
authors.initials: J
authors.lastname: Reiser
authors.affiliation: Dengue Vaccine Initiative, International Vaccine Institute, Seoul, Korea.
authors.forename: In-Kyu
authors.initials: IK
authors.lastname: Yoon
mesh_terms: D000367:Age Factors; D019138:Antibodies, Blocking / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood*; D003715:Dengue / Q000453:epidemiology* / Q000276:immunology* / Q000473:pathology; D003716:Dengue Virus / Q000145:classification* / Q000276:immunology* / Q000472:pathogenicity; D054884:Host-Pathogen Interactions; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007223:Infant; D007231:Infant, Newborn; D065288:Serogroup; D013785:Thailand / Q000453:epidemiology
chemical_list: D019138:Antibodies, Blocking; D000914:Antibodies, Viral