Identificação etiológica de quadros dengue-símile no Ceará, no ano de 2008

Abstract

Dengue is the most important arborvirosis in the world, causing approximately 100 millions cases of classical dengue fever (DF) and more than 250.000 of dengue hemorrhagic fever (DHF), annually. The dengue virus (DENV) belongs to the Flaviviridae family and its infection causes a wide clinical spectrum ranging from assymptomatic forms to severe manifestations, potentially fatal, as in hemorrhagic forms or dengue shock syndrome (DSS). Most of times the disease presents inespecific symptoms. Thus, DF is difficult to distinguish from other acute febrile illnesses, including arboviral ones and leptospirosis, based only on clinical criteria. Given this, the aim of this study was to identify the etiology of 82 patients with clinical picture of dengue-like illness, negative in DENV isolation. The virus isolation was done in Laboratorio Central de Saúde Pública do Ceará (LACEN-CE), Brazil, in 2008. In the present study, the serum samples from these patients were evaluated for dengue infection by IgM-ELISA (PanBio Diagnostics®) and RT-PCR, following Lanciotti et alli protocol (1992). Negative samples to dengue infection were tested to leptospirosis by IgM-ELISA (PanBio Diagnostics®). Seventy-three patients were also tested for hantavirus infection by IgM and IgG by ELISA and RT-PCR. Dengue infection was diagnosed in 35 patients (35/82; 42.68%) of which all were positive in IgM-ELISA, and 4 were also positive in RT-PCR. Of 47 (47/82; 57.32%) DENV-negative samples, only 43 were tested to evaluate lesptospiral infection because of insufficient sample volume. Six patients (6/82; 7,32%) were positive to leptospirosis in the IgM-ELISA. Three patients were positives to hantavirus infection, but only 1 (1/82; 1,22%) was positive in the IgM-ELISA and the two others, in the IgG-ELISA. Thirty and five patients (35/82; 42,68%) remained negative em all tests. They were classified as having other febril illness (OFI). To the best of our knowledge, this is the first evidence of hantavirus infection in humans in the state of Ceará, Brazil. These diseases, including leptospirosis, may cause infection clinically indistinguishable from DF and therefore should be included in the differential diagnosis of febrile illnesses in this setting.