title: Epidemiological studies on dengue virus type 3 in Playa municipality, Havana, Cuba, 2001-2002.
abstract: OBJECTIVE
  Recognizing the uniqueness of secondary dengue virus (DENV)-1/3 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) cases at an interval of 24 years, we sought to estimate DENV infections as well as the ratios between mild disease and DHF/DSS by DENV infection sequence in Playa District (Havana, Cuba) during the 2001-2002 outbreak of dengue virus type 3 (DENV-3).
  
  
  METHODS
  A retrospective seroepidemiological study was conducted in 2003 in Playa District. Blood samples were collected from a 1% random sample of residents and were studied for the prevalence of dengue neutralizing antibodies.
  
  
  RESULTS
  DENV-3 was found to have infected 7.2% (95% confidence interval (95% CI) 6.0-8.4%) of susceptible individuals (the entire cohort), the majority of whom experienced silent infections. Virtually every individual who had a secondary infection in the sequence DENV-1 then DENV-3 became ill, with a ratio of severe to mild cases of 1:35 (95% CI 1:67-1:23). Secondary infections in the sequence DENV-2/3 were less pathogenic than DENV-1/3. Mild disease accompanying secondary DENV2/3 occurred at a ratio of 1:4.49 infections (95% CI 1:5.77-1:3.42) secondary infections.
  
  
  CONCLUSIONS
  The results obtained highlight the role of the infecting serotype and also the sequence of the viral infection in the clinical outcome of a dengue infection.
authors.affiliation: Department of Virology, PAHO/WHO Collaborating Center for Study of Dengue and its Vector, Pedro Kouri Tropical Medicine Institute, Autopista Novia del Mediodía km 6, PO Box 601, Marianao 13, Havana, Cuba. lupe@ipk.sld.cu
authors.forename: Maria G
authors.initials: MG
authors.lastname: Guzman
authors.forename: Angel
authors.initials: A
authors.lastname: Alvarez
authors.forename: Susana
authors.initials: S
authors.lastname: Vazquez
authors.forename: Mayling
authors.initials: M
authors.lastname: Alvarez
authors.forename: Delfina
authors.initials: D
authors.lastname: Rosario
authors.forename: Otto
authors.initials: O
authors.lastname: Pelaez
authors.forename: Guillermo
authors.initials: G
authors.lastname: Cruz
authors.forename: Rosmari
authors.initials: R
authors.lastname: Rodriguez
authors.forename: Alequis
authors.initials: A
authors.lastname: Pavon
authors.forename: Annia
authors.initials: A
authors.lastname: Gonzalez
authors.forename: Luis
authors.initials: L
authors.lastname: Morier
authors.forename: Dydie
authors.initials: D
authors.lastname: Ruiz
authors.forename: Gustavo
authors.initials: G
authors.lastname: Kouri
authors.forename: Scott B
authors.initials: SB
authors.lastname: Halstead
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057134:Antibodies, Neutralizing / Q000097:blood; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000453:epidemiology* / Q000821:virology; D003462:Cuba / Q000453:epidemiology; D003716:Dengue Virus / Q000472:pathogenicity*; D004196:Disease Outbreaks; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012703:Serotyping; D019595:Severe Dengue / Q000453:epidemiology* / Q000821:virology; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing