Key socio-economic and environmental factors in the reappearance of the Aedes aegypti mosquito in the Atacama (North Chile) Desert areas and mitigation risk measures.

Resumen

In the last 25 years it has had a significant increase at a global level, reaching areas where it waseradicated, such as the reappearance in the extreme north of Chile, an area covered by theAtacama Desert. This mosquito is closely related to human settlements, which present risks thatlie in the capacity of transmission of diseases caused by arboviruses by Aedes aegypti such as:Zika, Chikungunya, Yellow Fever and Dengue. The last one is the most important viral diseasetransmitted by mosquitoes in humans with more than 50 million estimated cases annually in over100 countries. The aim of this study is to analyze the urban and environmental variables thatdetermine the reappearance of the vector and to propose mitigation measures to reduce the risksof contagion. This study is located in the city of Arica (18°28'28.6'' S 70°17'52.5'' W) in the extremenorth of the Atacama Desert, which has extraordinary habitability conditions characterized byrivers that are reactivated by summer rains in the Andes and valleys with agro-ecologicalproductivity. The Pan American Health Organization determined the end of the presence of themosquito in 1961 and its reappearance from 2016 in continental Chile. About the methods, theHealth Authority established action limits based on the risks presented by these areas in terms ofhealth interest and location, through inspections that allowed the identification of the vulnerabilityof each area. This was done by means of inspections that made it possible to identify thevulnerability of the sites. The discovery sites were geolocated according to the phenomenology ofthe species, considering the radius of flight among other phenological characteristics. The resultsallowed the identification of critical areas for the establishment of focus. The residential typologiesof the sites were classified as industrial zones and suburbs in the urban limits with space-timecoincidences. During 2016, 56 cases were found in urban and peri-urban areas between May andJune. In 2018 there were findings between March-April with 14 cases in industrial and residentialareas, while in 2019 there were findings between January-May and December with a total of 27positive cases in peri-urban areas. In conclusion, there is evidence of a shift in findings fromresidential areas of paired housing (2016) to industrial areas (2018) and to suburbs in 2019. Thereis evidence of a deseasonalization in the findings of the mosquito, being a problem that must becontrolled throughout the year. Therefore, there is an urgent need to find work methodologies that can anticipate the detection of mosquitoes in sites that present a high risk, in order to takedecisions on health management and apply control measures to regulate the accumulation ofwater. Environmental Education is proposed as a method to promote citizen awareness to face therisks associated with the vector together with government, academic and communitycoordination, cooperation and collaboration.