title: Dengue fever occurrence and vector detection by larval survey, ovitrap and MosquiTRAP: a space-time clusters analysis.
abstract: The use of vector surveillance tools for preventing dengue disease requires fine assessment of risk, in order to improve vector control activities. Nevertheless, the thresholds between vector detection and dengue fever occurrence are currently not well established. In Belo Horizonte (Minas Gerais, Brazil), dengue has been endemic for several years. From January 2007 to June 2008, the dengue vector Aedes (Stegomyia) aegypti was monitored by ovitrap, the sticky-trap MosquiTRAP™ and larval surveys in an study area in Belo Horizonte. Using a space-time scan for clusters detection implemented in SaTScan software, the vector presence recorded by the different monitoring methods was evaluated. Clusters of vectors and dengue fever were detected. It was verified that ovitrap and MosquiTRAP vector detection methods predicted dengue occurrence better than larval survey, both spatially and temporally. MosquiTRAP and ovitrap presented similar results of space-time intersections to dengue fever clusters. Nevertheless ovitrap clusters presented longer duration periods than MosquiTRAP ones, less acuratelly signalizing the dengue risk areas, since the detection of vector clusters during most of the study period was not necessarily correlated to dengue fever occurrence. It was verified that ovitrap clusters occurred more than 200 days (values ranged from 97.0±35.35 to 283.0±168.4 days) before dengue fever clusters, whereas MosquiTRAP clusters preceded dengue fever clusters by approximately 80 days (values ranged from 65.5±58.7 to 94.0±14. 3 days), the former showing to be more temporally precise. Thus, in the present cluster analysis study MosquiTRAP presented superior results for signaling dengue transmission risks both geographically and temporally. Since early detection is crucial for planning and deploying effective preventions, MosquiTRAP showed to be a reliable tool and this method provides groundwork for the development of even more precise tools.
authors: Lab. Ecologia Química de Insetos Vetores, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais. Av. Presidente Antônio Carlos, Belo Horizonte, MG, Brazil. diogopom@gmail.com
authors: Diogo Portella Ornelas
authors: DP
authors: de Melo
authors: Luciano Rios
authors: LR
authors: Scherrer
authors: Álvaro Eduardo
authors: ÁE
authors: Eiras
mesh_terms: D000330:Aedes / Q000502:physiology*; D000818:Animals; D001938:Brazil / Q000453:epidemiology; D016000:Cluster Analysis; D003625:Data Collection; D003715:Dengue / Q000453:epidemiology* / Q000635:transmission*; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000502:physiology*; D007814:Larva / Q000502:physiology; D015203:Reproducibility of Results; D062211:Spatio-Temporal Analysis