title: Incidence of primary dengue virus infections in Southern Vietnamese children and reactivity against other flaviviruses.
abstract: OBJECTIVE
  To study the incidence of asymptomatic primary dengue infections among children and reactivity against other flaviviruses.
  
  
  METHODS
  A total of 216 children, who had no dengue-specific IgG antibodies during a serosurvey in 2003 were re-examined 23 months later to determine if seroconversion had occurred. Dengue-specific IgG was demonstrated with enzyme-linked immunosorbent assay (ELISA) and reactivity patterns against other flaviviruses were assessed by using immunofluorescence assay (IFA).
  
  
  RESULTS
  Sixty-six children had seroconverted for dengue virus-specific IgG; the true annual incidence of primary dengue was thus 17.3% (95% CI: 13.8-21.4). Japanese Encephalitis virus (JEV)-specific IgG antibodies were detected by IFA among three (4.6%) samples that showed seroconversion in the dengue ELISA, because of cross-reactivity.
  
  
  CONCLUSIONS
  Our findings highlight the high incidence of dengue among Vietnamese children; JEV infections are rare. The true annual incidence of dengue can be estimated with a single cross-sectional seroprevalence survey.
authors: Division of Infectious Diseases, Tropical Medicine & AIDS, Academic Medical Center, Amsterdam, The Netherlands. t.d.thai@amc.uva.nl
authors: Khoa T D
authors: KT
authors: Thai
authors: Tran Thi Thanh
authors: TT
authors: Nga
authors: Nguyen
authors: N
authors: Van Nam
authors: Hoang Lan
authors: HL
authors: Phuong
authors: Phan Trong
authors: PT
authors: Giao
authors: Le Quoc
authors: le Q
authors: Hung
authors: Tran Quang
authors: TQ
authors: Binh
authors: Gerard J J
authors: GJ
authors: van Doornum
authors: Peter J
authors: PJ
authors: de Vries
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D003430:Cross-Sectional Studies; D003715:Dengue / Q000453:epidemiology* / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D018177:Flavivirus Infections / Q000276:immunology*; D006801:Humans; D015994:Incidence; D008297:Male; D014744:Vietnam / Q000453:epidemiology
chemical_list: D000914:Antibodies, Viral