Vigilância epidemiológica de Chikungunya em humanos e vetores: proposta de modelo para o município de Natal-RN

Abstract

The objective of this work was to develop a model for surveillance of arboviruses in humans and vectors in the city of Natal, State of Rio Grande do Norte. Culicidae and human cases with signs and symptoms compatible with arbovirus infection were studied. The samples were received from February to July 2016, from an active search carried out by the epidemiological surveillance team of the Center for Zoonoses Control (CCZ) of the Municipality of Natal. Viral RNA was extracted using the QIAamp Viral kit. The research of the Chikungunya was carried out using the reverse transcription technique followed by the real-time polymerase chain reaction (TaqMan Ⓡ System). A total of 104 human cases were studied and 57 (54.8%) of cases were positive for Chikungunya. In the vector fields, a total of 816 were studied, being 421 (51.59%) Aedes aegypti, 312 Aedes albopictus (38.23%), 56 (6.86%) Wyeomyia spp., 23 (2.81%) Culex quinquefasciatus, 3 (0.36%) Ochlerotatus scapularis and 1 (0.12%) Haemagogus leucocelaenus. A total of 5 Aedes aegypti pools were positive for Chikungunya, representing a Minimum Infection Rate (MIR) of 11.87. In the same analysis, a total of 2 pools of Aedes albopictus were positive for Chikungunya (MIR = 6.41). It was possible to detect the Chikungunya virus in 1 pool of Wyeomyia spp (MIR = 17.85). CHIKV was not identified in pools of Ochlerotatus scapularis and Haemagogus leucocelaenus species. The arbovirus surveillance model in humans and vectors proposed by this study provided the Natal Zoonoses Control Center with precise information about the places with the greatest circulation of arboviruses and the presence of vectors. This information allows directing local vector control actions and contributed to reducing the impact of the CHIKV outbreak in the city of Natal-RN during 2016.