Public health institutions with sectorized structure and low integration among field teams, old-fashioned practices such as paper-based storage system, and poorly qualified health agents have limited ability to conduct accurate surveillance and design effective timely interventions. Herein, we describe the steps taken by the Zoonosis Control Center of Foz do Iguaçu (CCZ-Foz) in the last 23 years to move from an archaic and sectorized structure to a modern and timely surveillance program embracing zoonotic diseases, venomous animal injuries, and vector-borne diseases epidemiology under the One Health approach. The full implementation of the One Health approach was based on 5 axes: (1) merging sectorized field teams; (2) adoption of digital solutions; (3) health agents empowerment and permanent capacitation; (4) social mobilization; and (5) active surveys. By doing so, notifications related to zoonotic diseases and venomous animals increased 10 and 21 times, respectively, with no impairment on arbovirus surveillance (major concern in the city). Open sources database (PostgreSQL) and software (QGis) are daily updated and create real-time maps to support timely decisions. The adoption of One Health approach increased preparedness for endemic diseases and reemerging and emerging threats such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).
objective In Brazil, the most common method of controlling outbreaks of arbovirus is by the use of chemical sprays, which kill the insect vector, Aedes aegypti. The main objective of this study was to evaluate the resistance of Ae. aegypti to the insecticide, malathion, in situ. The location of this study was the municipality of Foz do Iguaçu, in the state of Paraná, Brazil. methods Ultra-low-volume (ULV) fogging equipment was used, by vehicle, to apply the insecticide in situ, and mosquito populations after treatment were compared with those of control areas. The resistance of strains collected from the municipality was compared to the Rockefeller strain under laboratory conditions. results We found 220 adult female specimens and 7423 eggs of Ae. aegypti in the areas subjected to UBV treatment, whereas 245 adult females and 10 557 eggs were found in the control areas. The UBV treatment area showed no significant difference compared to the control area, for all the indices. Mortality of the Rockefeller colony varied more quickly when there were slight variations in malathion concentration than the Foz do Iguaçu population. keywords Arboviruses, entomological surveillance, chemical control, ultra-low volume (ULV), Foz do Iguaçu Sustainable Development Goals (SDGs): SDG 3 (good health and well-being), SDG 15 (life on land), SDG 17 (partnerships for the goals)
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.
Arboviruses transmitted by Aedes aegypti in urban environments have spread rapidly worldwide, causing great impacts on public health. The development of reliable and timely alert signals is among the most important steps in designing accurate surveillance systems for vector-borne diseases. In July and September 2017, we conducted a pilot study to improve an existing integrated surveillance system by using entomo-virological surveillance to prioritize areas to conduct active searches for individuals with arbovirus infection symptoms. Foz do Iguaçu City has a permanent entomo-virological surveillance system with approximately 3,500 traps to capture Aedes sp. in the adult stage. The Aedes aegypti females are captured alive and human samples are submitted to RT-qPCR (real-time qPCR) screening for DENV, ZIKV, and CHIKV diagnosis. Of the 55 Ae. aegypti mosquitoes tested in July 2017, seven (12.7%) were considered positive for DENV-2 and three (5.4%) for CHIKV. In September, we tested a sample of 54 mosquitoes, and 15 (27.7%) were considered infected by DENV-2. We created 25 circumferences with 150-m radius each to perform an active survey to identify symptomatic householders. In July, we selected one circumference, and five (35.7%) patients were positive for DENV, whereas two (14.3%) for CHIKV. In September, we selected four circumferences, and, from the 21 individuals sampled, nine (42.8%) were positive for DENV-2. A statistical model with a binomial response was used to estimate the number of cases in areas without active surveys, i.e., 20 circumferences. We estimated an additional 83 symptomatic patients (95% CI: 45–145) to be found in active searches, with 38 (95% CI: 18–72) of them confirming arbovirus infection. Arbovirus detection and serotyping in mosquitoes, but also in symptomatic individuals during active surveys, can provide an alert signal of early arbovirus transmission.
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