Entomo-Virological Aedes aegypti Surveillance Applied for Prediction of Dengue Transmission: A Spatio-Temporal Modeling Study

Abstract

Currently, DENV transmitted primarily by Aedes aegypti affects approximately one in three people annually. The spatio-temporal heterogeneity of vector infestation and the intensity of arbovirus transmission require surveillance capable of predicting an outbreak. In this work, we used data from 4 years of reported dengue cases and entomological indicators of adult Aedes collected from approximately 3500 traps installed in the city of Foz do Iguaçu, Brazil, to evaluate the spatial and temporal association between vector infestation and the occurrence of dengue cases. Entomological (TPI, ADI and MII) and entomo-virological (EVI) indexes were generated with the goal to provide local health managers with a transmission risk stratification that allows targeting areas for vector control activities. We observed a dynamic pattern in the evaluation; however, it was a low spatio-temporal correlation of Ae. aegypti and incidence of dengue. Independent temporal and spatial effects capture a significant portion of the signal given by human arbovirus cases. The entomo-virological index (EVI) significantly signaled risk in a few areas, whereas entomological indexes were not effective in providing dengue risk alert. Investigating the variation of biotic and abiotic factors between areas with and without correlation should provide more information about the local epidemiology of dengue.

Optimising the surveillance of Aedes aegypti in Brazil by selecting smaller representative areas within an endemic city

“…However, further investigations demonstrated the inability of the indicators to predict space-time occurrence with T A B L E 2 Akaike information criteria results ranking the most parsimonious a priori scenario models (descending order) that predict the incidence of dengue cases based on surveys of Aedes aegypti mosquitoes at Geographic Unity Scale, Foz do Iguaçu, Brazil. a geographic precision at sub-municipal levels with spatial units of an average of 1500 properties [34]. The TPI and ADI were estimated after inspecting a total of approximately 3500 Adultraps distributed over the city in a ratio of one every 25 premises [32].…”

“…aegypti infestation rates in the adult stage, highlighting both TPI and ADI are capable to predict dengue outbreaks 4 weeks in advance. However, further investigations demonstrated the inability of the indicators to predict space–time occurrence with geographic precision at sub‐municipal levels with spatial units of an average of 1500 properties [34]. The TPI and ADI were estimated after inspecting a total of approximately 3500 Adultraps distributed over the city in a ratio of one every 25 premises [32].…”

“…Traps are inspected every 2 months to generate entomological indicators based on adult sampling, which has proven to predict dengue outbreaks up to 4 weeks in advance but failed to determine in which region of the city such increase in dengue might occur. Therefore, the early warning system developed in Foz do Iguaçu has a strong temporal prediction but lacks spatial accuracy [33,34]. In that sense, the aim of this study is to identify smaller areas within the city that could be representative of larger regions to improve the actual earlywarning system by providing better management for DENV outbreaks.…”

Larvicidal Effects of New Organophosphorus Schiff base compounds against Dengue Fever Vector Aedes aegypti (Diptera; Culicidae)

“…Uncontrolled urbanization, rising temperatures, and a lack of effective long-term vector control tools have aided Aedes aegypti adaptation to urban environments throughout the world. [9][10][11][12].…”

Biology, Control and Zoonotic Role of Disease Vectors

“…Claver et al [ 8 ] reported relatively modest vector competence for Aedes aegypti in Vientiane, Lao PDR, to transmit the Asian and ECSA-IOL lineages of chikungunya virus, which may be influenced by the longevity and density of female mosquitoes. Leandro et al [ 9 ] evaluated the spatial and temporal association between vector infestation and the occurrence of dengue cases and reported a dynamic pattern indicating significant risks in certain areas of Foz do Iguaçu, Brazil, based on the entomological–virological index, while entomological indices were not effective in measuring dengue risk. Another study tested the efficacy of modifications to sewerage structures as an alternative to the use of biocides to prevent the breeding of Culex pipiens and Aedes albopictus in Barcelona, Spain [ 10 ].…”