Investigação de dengue virus circulantes em Juiz de Fora- MG

Abstract

Dengue is the most important arboviral disease to public health in Brazil. The city of Juiz de Fora has undergone several dengue epidemics in recent years, with the record of severe cases and deaths. Given that, this work aimed to investigate the circulation of dengue virus (DENV) in Aedes aegypti collected from the natural environment and in clinical samples from patients with clinical symptoms of dengue, using molecular and serological approaches. Samples of Aedes aegypti (larvae and mosquitoes) and serum of patients were used for total RNA extraction, and the total RNA was used for detection of DENV by RT-PCR. Clinical samples from patients who had fever for up to six days were tested for Dengue virus NS1 protein. Furthermore, analysis of patient records was performed in which we could check the day the fever began the hematological data (hematocrit, total leukocyte count, and platelet count) and serologic response (IgM and/or IgG). Aedes aegypti was collected in all regions of the city and from the 163 larvae pools that were analyzed, DENV was detected in six (five pools DENV-1 positive and one pool DENV-2 positive). These pools were collected in the North, Centre and South regions. A total of 166 serum samples were analyzed for molecular detection, being six DENV positive (one serum sample was DENV-1 positive and five serum samples were DENV-2 positive). Sixty clinical samples were tested for NS1 and 11 (18.33%) were positive. From the analysis of patient records was possible to observe that 132 had serology results. Of these, 39/132 (29.54%) were IgM positive, 9/132 (6.81%) were IgG positive and 15/132 (11.36%) were IgM and IgG positive. In addition, from 109 patients hematological data were available. Among these, 18 (16.51%) patients had less than the reference value, 32 (29.35%) developed leukocyte hematocrit below 3.500/mm3 and 24 (22.02%) had platelet counts below the reference value. This is the first study of molecular investigation of DENV in Juiz de Fora, and the results indicated the co-circulation of serotypes 1 and 2 in Juiz de Fora and the occurrence of DENV transovarial transmission in Aedes aegypti. The combination of molecular and serological tests allowed the identification of 50 patients in the acute phase of the disease and 22 in the convalescent phase. The knowledge of viral types circulating in the municipality and the diagnosis of dengue in patients using different techniques constitute valuable information from an epidemiological point of view and help to structure public policies aiming the control of dengue.