The increase in the number of more serious forms of dengue fever among cases in the city of Belém, Brazil has astounded local authorities. The objective of this study was to conduct a critical analysis of hematologic and serologic findings of patients with clinical suspicion of dengue seen at a clinical laboratory in Belém in Pará State. This retrospective study involved 210 patients who were referred to the Laboratory of Clinical Pathology Dr. Paulo C. Azevedo in Belém, in the period of February and March of 2007, with requests for a complete blood count and serological test for IgM to confirm the diagnosis of dengue. Of the cases studied, 51/210 (24.3%) presented with thrombocytopenia and 53/210 (25.2%) leukopenia. The serologic test for IgM was positive in 47.1% (99/210) of cases. A statistically significant association (p<0.05) was observed only among patients who presented with thrombocytopenia (33/99) and positive serology for dengue, suggesting that the hematological alterations of leukopenia and thrombocytopenia, frequently associated with this illness, may not be present at the beginning of the infection. It is therefore essential to carry out a serologic test for IgM to confirm a diagnosis of dengue.
Dengue; virology; hematology; diagnosis
