Diagnóstico, genótipo e epidemiologia de casos de Dengue-4 no Estado de Sergipe – Nordeste do Brasil

Abstract

Introduction: This study analyzes the diagnostic methods routinely used in at Dengue National Program for the circulating serotypes of dengue screening of the in Brazil and describe epidemiological characteristics of the dengue cases in Sergipe, Northeast Brazil. Methods: Blood samples were requested from the Sergipe Central Laboratory from September 2011 to September 2012 and submitted to semi-nested RT-PCR for dengue. Positive samples for DENV-4 were confirmed by indirect immunofluorescence and had the DNA sequenced. Patients epidemiological data were obtained from the reportable diseases forms filled by the Health service. Results: The majority of the samples of Aracaju were from people who live in medium-low and low income areas, where public heath service dependence is high. Females were more affected and the predominant age group was 19-59 years. The months of highest incidence were January, February and March, 2012. This study showed sensitivity of 34.9% of the NS1 Ag test for dengue, comparing with the result of RT- PCR. Our positive samples were 113 of DENV-4 and 1 of DENV-1, detecting cases of DENV-4 since the first month of the study (September, 2011). All samples studied were grouped within the II genotype of DENV-4. Conclusion: The sensitivity and specificity of the PlateliaTM dengue NS1 Ag test as a screening method for monitoring circulating dengue serotypes must be reevaluated. Regional endo-epidemic profiles should also be considered due to the prevalence of secondary responses to previous DENV infection which may interfere whit NS1 results.