[Early indicators of dengue infection in children].

Objective: To identify clinical manifestations and laboratory findings useful for the early diagnosis of dengue in children.
Materials and Methods: We prospectively evaluated 125 children (aged 5 to 12 years old) with acute febrile syndrome with no apparent etiology. Paired serologic tests and/or viral culture were performed and dengue infection was confirmed in 40 patients and ruled out in 68 (17 indefinite cases). Early clinical manifestations (within the first 4 days of the disease) in the groups with dengue and other causes of febrile syndrome were compared. Independent indicators of dengue were determined in a multivariate logistic regression analysis.
Results: When clinical manifestations and complete blood count were considered, the independent indicators of dengue were: absence of nasal discharge, facial flushing, and leukocyte count < or = 4,500/.l. With at least two of these findings, a sensitivity of 67 % and a specificity of 72 % for the diagnosis of dengue were obtained. When coagulation tests were considered, a model for diagnosis was composed of: absence of nasal discharge, leukocyte count < or = 4500/.l, prothrombin time > 14 seconds, and partial thromboplastin time > 29 seconds. Two of these findings suggested a diagnosis of dengue with a sensitivity of 90 % and a specificity of 52.9 %. With at least 3 findings, specificity increased to 89.7 % and sensitivity decreased to 50 %. The presence of the four components of this latter model shows a specificity of 100 %.
Conclusions: Some clinical manifestations and simple laboratory tests could aid the early detection of dengue infection in children.