Evidence of Co-Circulation of Multiples Arbovirus Transmitted by Aedes Sp. Based on Laboratorial Syndromic Surveillance At Health Unit in Slum Area of Federal District, Brazil

Abstract

Background: Vector-borne diseases, especially arbiviruses transmitted by Aedes sp. mosquitos, should be a health policy priority in Brazil. Despite this urgency, there are significant limitations in the traditional surveillance system, such as lack of timely notification in identifying outbreaks at their onset and the systemic dismantling of entomological control in recent decades. Methods: Laboratory syndromic surveillance for acute febrile and/or exanthematous syndromes was developed at a health unit in a favela (Portuguese for slum) of the Federal District in order to identify the circulation of arboviruses transmitted by Aedes sp. mosquitos. Between June/2019 and March/2020, 131 valid participants were identified and tested by RT-PCR for dengue (by serotype), Zika and Chikungunya virus acute infection; and ELISA-IgM for dengue fever and Chikungunya 15-21 days after symptom onset, when the participant reported no respiratory signs (cough and/or coryza). The results obtained were compared with traditional epidemiological surveillance data for the study area. Results: At least 3 DENV-1 (2.3%), 4 DENV-2 (3%) and 1 CHIKV (0.7%) cases were confirmed in the laboratory, showing evidence of hyperendemicity even though laboratory syndromic surveillance had not reached the historic peak dengue fever months in the Federal District (April-May). When the results obtained here were compared with traditional epidemiological surveillance data, a significant discrepancy was observed, including underreporting of Chikungunya infection. Conclusions: in addition to the risks posed to the study population, the area investigated and its respective socioenvironmental profile may be a potential site for spreading the virus, given the cosmopolitan presence of Aedes sp. and human mobility in the Federal District. It is also suggested that traditional epidemiological surveillance may be notifying different acute viral infections such as dengue fever, while underreporting other arboviruses transmitted by Aedes sp. mosquitos in the Federal District.