title: Seroepidemiology of dengue virus infection among adults in Singapore.
abstract: BACKGROUND
  To determine the seroepidemiology of dengue virus infection in a representative sample of the adult resident population aged 18 years old to 74 years old in Singapore and to estimate the proportion of asymptomatic dengue infection during the 2004 epidemic.
  
  
  METHODS
  The study was based on 4152 stored blood samples collected between September and December 2004 from participants aged 18 years old to 74 years old during the 2004 National Health Survey. Sera were tested for IgG and IgM antibodies using a commercial test kit (PanBio Capture/Indirect ELISA).
  
  
  RESULTS
  Of the study population, 59.0% and 2.6% tested positive for dengue IgG (past infection) and IgM/high-titre IgG (recent infection), respectively. Only 17.2% of young adults aged 18 years old to 24 years old were dengue IgG positive. Multivariate analyses showed that older age, Indian ethnicity and male gender were significantly associated with past infection, whereas only age was significantly associated with recent dengue infection. Based on the dengue cases notified during the period of survey, it was estimated that for every 23 individuals recently infected with dengue, only 1 was reported to the health authority as a clinical case.
  
  
  CONCLUSIONS
  The Singapore population is highly susceptible to dengue epidemics despite its aggressive Aedes prevention and control programme. The finding of a high proportion of unreported cases due to asymptomatic and subclinical infection poses a challenge for dengue control.
authors.affiliation: Communicable Diseases Division, Ministry of Health, Singapore. arguzia@singnet.com.sg
authors.forename: Yik Weng
authors.initials: YW
authors.lastname: Yew
authors.forename: Tun
authors.initials: T
authors.lastname: Ye
authors.forename: Li Wei
authors.initials: LW
authors.lastname: Ang
authors.forename: Lee Ching
authors.initials: LC
authors.lastname: Ng
authors.forename: Grace
authors.initials: G
authors.lastname: Yap
authors.forename: Lyn
authors.initials: L
authors.lastname: James
authors.forename: Suok Kai
authors.initials: SK
authors.lastname: Chew
authors.forename: Kee Tai
authors.initials: KT
authors.lastname: Goh
mesh_terms: D000293:Adolescent; D000328:Adult; D000330:Aedes; D000368:Aged; D000818:Animals; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D003715:Dengue / Q000453:epidemiology* / Q000635:transmission; D003716:Dengue Virus; D004196:Disease Outbreaks; D005260:Female; D006306:Health Surveys; D006801:Humans; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009032:Mosquito Control; D015999:Multivariate Analysis; D016017:Odds Ratio; D011159:Population Surveillance; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012846:Singapore / Q000453:epidemiology; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M