Detecção molecular do vírus dengue em pacientes com a suspeita clínica da doença atendidos em Maceió, Alagoas

Abstract

Dengue is the most important arthropod-borne viral disease in the world. The dengue virus (DENV) are single-stranded RNA viruses with positive polarity that belong to the family Flaviviridae, genus Flavivirus. There are four classic serotypes of dengue virus serologically distinct (DENV-1, DENV-2, DENV-3, DENV-4). The DENV infection causes a spectrum of illness ranging from asymptomatic infection or mild febrile illness to dengue without warning signs, dengue with warning signs, and severe dengue. Specific laboratory tests performed in the diagnosis of dengue can be accomplished through the detection of the presence of antibodies, virus isolation, detection of the viral genome by reverse transcription followed by polymerase chain reaction (RT-PCR), NS1 antigen detection, and immunohistochemistry. In the State of Alagoas, the diagnosis is performed only by serology and virus isolation. Thus, the aim of this study was to perform the molecular detection of DENV in sera samples from individuals with clinical suspect of the disease attended in Maceió/AL, by the methods of one-step real time RT-PCR, multiplex semi-nested- PCR and nested PCR. Sera samples from 55 patients were collected and tested for detection of the 5’UTR region and of parts of the C, prM and NS5 genes at the viral genome. Of the total samples, in 15 (27.27%) was detected DENV genome in at least one of the used tests. Of these, 13 (86.67%) were positive by One-step real time RT-PCR. The viral serotype could be determined in 9 samples (60%), of which 8 (88.9%) presented DENV-4 and 1 presented (11.1%) DENV-3. Most sera samples included in the study was collected within the period of viremia and were obtained from patients who had symptoms suggestive of dengue. These data suggest that other members from genera Flavivirus may be causing infections in Maceió, but misdiagnosed as dengue. However, further studies aiming the molecular and serological screening for other arboviruses are necessary to confirm this hypothesis.