ABSTRACT
We developed a correlative model at high resolution for predicting the distribution of one of the main vectors of Crimean-Congo haemorrhagic fever virus (CCHFV), Hyalomma marginatum, in a recently colonised area, namely southern France. About 931 H. marginatum adult ticks were sampled on horses from 2016 to 2019 and 2021 in 14 southern French departments, which resulted in the first H. marginatum detection map on a large portion of the national territory. Such updated presence/absence data, as well as the mean number of H. marginatum per examined animal (mean parasitic load) as a proxy of tick abundance, were correlated to multiple parameters describing the climate and habitats characterising each collection site, as well as movements of horses as possible factors influencing tick exposure. In southern France, H. marginatum was likely detected in areas characterised by year-long warm temperatures and low precipitation, especially in summer and mostly concentrated in autumn, as well as moderate annual humidity, compared to other sampled areas. It confirms that even in newly invaded areas this tick remains exclusively Mediterranean and cannot expand outside this climatic range. Regarding the environment, a predominance of open natural habitats, such as sclerophyllous vegetated and sparsely vegetated areas, were also identified as a favourable factor, in opposition to urban or peri-urban and humid habitats, such as continuous urban areas and inland marshes, respectively, which were revealed to be unsuitable. Based on this model, we predicted the areas currently suitable for the establishment of the tick H. marginatum in the South of France, with relatively good accuracy using internal (AUC = 0.66) and external validation methods (AUC = 0.76 and 0.83). Concerning tick abundance, some correlative relationships were similar to the occurrence model, as well as the type of horse movements being highlighted as an important factor explaining mean parasitic load. However, the limitations of estimating and modelling H. marginatum abundance in a correlative model are discussed.
Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Horse Diseases , Ixodidae , Ticks , Animals , France/epidemiology , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/veterinary , HorsesABSTRACT
Resumen Introducción: El dengue se encuentra en 128 países a nivel mundial, produciendo 390 millones de infecciones cada año, solo 96 millones se manifiestan clínicamente. En el Paraguay, la primera epidemia se registró en el período 1988-1989 con la circulación de DEN-1. En el año 2018, se ha registrado 3.414 casos confirmados en todo el país, en Itapúa se registraron 684 probables y167 confirmados. Objetivo: Describir la situación epidemiológica del Dengue en Encarnación 2018. Materiales y Métodos: Estudio observacional de diseño retrospectivo en el cual se revisaron fichas epidemiológicas del 2018, se incluyeron solo aquellas notificaciones de pacientes provenientes de la ciudad de Encarnación. Este estudio contó con la aprobación del Comité de Ética de la Universidad Autónoma. Resultados: En el 2018 se registraron en Encarnación 1418 notificaciones de los cuales 8% fueron confirmados, y 48% sospechosos, el 33 % correspondieron a la zona rural y el 67 % a la zona urbana. Discusión: Al observar las cifras de casos confirmados para Dengue se tienen valores inferiores al 10%, sin embargo, el 2018 se caracterizó por tener una epidemia a nivel regional, así como también nacional, por lo tanto, resulta clave el análisis en el contexto epidemiológico. Conclusión: El reporte de casos confirmados revela un bajo porcentaje de la enfermedad, en contraposición al alto valor en número de casos sospechosos, por lo tanto, allí radica la importancia de la epidemiología pues en caso de no ser confirmada por métodos laboratoriales podrá ser igualmente tratada a tal manera de evitar posibles complicaciones.
Abstract Introduction : Dengue is found in 128 countries worldwide, producing 390 million infections every year, only 96 million manifests clinically. In Paraguay, the first epidemic was recorded in the period 1988-1989 with the circulation of DEN-1. In 2018, 3,414 confirmed cases were registered throughout the country, in Itapúa 167 confirmed and 684 probable were registered. Objective: Describe the epidemiological situation of Dengue in Encarnacion 2018 Materials and Methods : An observational retrospective study in which epidemiological records of 2018 were reviewed, only those notifications of patients from the city of Encarnacion were included. This study was approved by the Ethics Committee of the Autonomous University. Results: In 2018, 1418 notifications were registered in Encarnacion, 8% of which were confirmed, and 48% suspected, 33% corresponded to the rural area and 67% to the urban area, 39% corresponded to the San Pedro neighborhood, 25% the downtown area, 19% San Isidro and 18% San Roque Gonzales. The age range with the highest number of cases was 20 to 39 years, 34% corresponded to the male sex and 39% to the female sex. Conclusion: The report of confirmed cases reveals a low percentage of the disease, as opposed to the high value in the number of suspected cases, therefore, therein lies the importance of epidemiology because if it is not confirmed by laboratory methods it can also be treated Such a way to avoid possible deaths
