title: Arterial hypertension and skin allergy are risk factors for progression from dengue to dengue hemorrhagic fever: a case control study.
abstract: BACKGROUND
  Currently, knowledge does not allow early prediction of which cases of dengue fever (DF) will progress to dengue hemorrhagic fever (DHF), to allow early intervention to prevent progression or to limit severity. The objective of this study is to investigate the hypothesis that some specific comorbidities increase the likelihood of a DF case progressing to DHF.
  
  
  METHODS
  A concurrent case-control study, conducted during dengue epidemics, from 2009 to 2012. Cases were patients with dengue fever that progressed to DHF, and controls were patients of dengue fever who did not progress to DHF. Logistic regression was used to estimate the association between DHF and comorbidities.
  
  
  RESULTS
  There were 490 cases of DHF and 1,316 controls. Among adults, progression to DHF was associated with self-reported hypertension (OR = 1.6; 95% CI 1.1-2.1) and skin allergy (OR = 1.8; 95% CI 1.1-3.2) with DHF after adjusting for ethnicity and socio-economic variables. There was no statistically significant association between any chronic disease and progression to DHF in those younger than 15 years.
  
  
  CONCLUSIONS
  Physicians attending patients with dengue fever should keep those with hypertension or skin allergies in health units to monitor progression for early intervention. This would reduce mortality by dengue.
authors.affiliation: Instituto de Saúde Coletiva, Salvador, Bahia, Brasil.
authors.forename: Maria Glória
authors.initials: MG
authors.lastname: Teixeira
authors.affiliation: Instituto de Saúde Coletiva, Salvador, Bahia, Brasil.
authors.forename: Enny S
authors.initials: ES
authors.lastname: Paixão
authors.affiliation: Instituto de Saúde Coletiva, Salvador, Bahia, Brasil.
authors.forename: Maria da Conceição N
authors.initials: Mda C
authors.lastname: Costa
authors.affiliation: Universidade Federal de Mato Grosso do Sul, Faculdade de Medicina, Cidade Universitária, Campo Grande, Mato Grosso do Sul, Brasil.
authors.forename: Rivaldo V
authors.initials: RV
authors.lastname: Cunha
authors.affiliation: Universidade Federal do Ceará, Instituto de Ciências de Saúde, Salvador, Bahia, Brasil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Pamplona
authors.affiliation: Instituto de Saúde Coletiva, Salvador, Bahia, Brasil.
authors.forename: Juarez P
authors.initials: JP
authors.lastname: Dias
authors.affiliation: Instituto de Ciências da Vida, Universidade Federal da Bahia, Salvador, Bahia, Brasil.
authors.forename: Camila A
authors.initials: CA
authors.lastname: Figueiredo
authors.affiliation: Instituto de Saúde Coletiva, Salvador, Bahia, Brasil.
authors.forename: Maria Aparecida A
authors.initials: MA
authors.lastname: Figueiredo
authors.affiliation: Case Western Reserve University, Cleveland, Ohio, United States of America.
authors.forename: Ronald
authors.initials: R
authors.lastname: Blanton
authors.affiliation: Instituto de Saúde Coletiva, Salvador, Bahia, Brasil.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Morato
authors.affiliation: Instituto de Saúde Coletiva, Salvador, Bahia, Brasil; Centro de Pesquisas Gonçalo Muniz, FIOCRUZ, Salvador, Bahia, Brazil.
authors.forename: Maurício L
authors.initials: ML
authors.lastname: Barreto
authors.affiliation: London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Rodrigues
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D003715:Dengue / Q000150:complications*; D018450:Disease Progression; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications*; D006973:Hypertension / Q000150:complications*; D007223:Infant; D016015:Logistic Models; D008297:Male; D012307:Risk Factors; D019595:Severe Dengue / Q000209:etiology*