title: Clinical, epidemiological and virological features of Dengue virus infections in Vietnamese patients presenting to primary care facilities with acute undifferentiated fever.
abstract: OBJECTIVE
  To explore clinical and virological characteristics and describe the epidemiology of dengue in patients who presented with acute undifferentiated fever (AUF) at primary health centers (PHC) in Binh Thuan Province, Vietnam.
  
  
  METHODS
  A prospective observational study was conducted from 2001 to 2006 to study the aetiology in AUF patients. Demographic and clinical information was obtained, and dengue polymerase chain reaction (RT-PCR) and serology were performed on a random selection of patients.
  
  
  RESULTS
  Three hundred fifty-one serologically confirmed dengue patients including 68 primary and 283 secondary infections were included in this study. In 25% (86/351) dengue virus (DENV) was detected by RT-PCR among which 32 DENV-1, 16 DENV-2, 1 DENV-3 and 37 DENV-4 were identified. The predominant dengue serotype varied by year with seasonal fluctuation: DENV-4 in 2001-2002, DENV-1 and DENV-2 from 2003 to 2006. Primary dengue was more common in children. Higher viraemia levels (P=0.010) were found in primary infections compared to secondary infections. DENV-1 infected patients had higher viraemia levels than DENV-2 (P=0.003) and DENV-4 (P<0.001) infected patients. Clinical symptoms were often seen in adults. Few differences in clinical symptoms were found between primary and secondary infection and no significant differences in clinical symptoms between the serotypes were observed.
  
  
  CONCLUSIONS
  Our data provide insight in the epidemiology, clinical profile and virological features of mild symptomatic dengue patients who presented to PHC with AUF in Vietnam.
authors.affiliation: Academic Medical Center, Amsterdam, the Netherlands. t.d.thai@amc.uva.nl
authors.forename: Khoa T D
authors.initials: KT
authors.lastname: Thai
authors.forename: Hoang Lan
authors.initials: HL
authors.lastname: Phuong
authors.forename: Tran Thi
authors.initials: TT
authors.lastname: Thanh Nga
authors.forename: Phan Trong
authors.initials: PT
authors.lastname: Giao
authors.forename: Le Quoc
authors.initials: le Q
authors.lastname: Hung
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van Nam
authors.forename: Tran Quang
authors.initials: TQ
authors.lastname: Binh
authors.forename: Cameron
authors.initials: C
authors.lastname: Simmons
authors.forename: Jeremy
authors.initials: J
authors.lastname: Farrar
authors.forename: Tran Thinh
authors.initials: TT
authors.lastname: Hien
authors.forename: H Rogier
authors.initials: HR
authors.lastname: van Doorn
authors.forename: Menno D
authors.initials: MD
authors.lastname: de Jong
authors.forename: Peter J
authors.initials: PJ
authors.lastname: de Vries
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000453:epidemiology* / Q000473:pathology* / Q000821:virology; D003716:Dengue Virus / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014744:Vietnam / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012367:RNA, Viral