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.

Author(s):  
Mauricio Gonzalez-Pacheco ◽  
Marcos Francos ◽  
Angelo Olivares ◽  
Xavier Úbeda

<p>The <em>Aedes aegypti</em> mosquito is the main urban vector that transmits Dengue disease worldwide. In the last 25 years it has had a significant increase at a global level, reaching areas where it was eradicated, such as the reappearance in the extreme north of Chile, an area covered by the Atacama Desert. This mosquito is closely related to human settlements, which present risks that lie in the capacity of transmission of diseases caused by arboviruses by <em>Aedes aegypti</em> such as: Zika, Chikungunya, Yellow Fever and Dengue. The last one is the most important viral disease transmitted by mosquitoes in humans with more than 50 million estimated cases annually in over 100 countries. The aim of this study is to analyze the urban and environmental variables that determine the reappearance of the vector and to propose mitigation measures to reduce the risks of contagion. This study is located in the city of Arica (18°28'28.6'' S 70°17'52.5'' W) in the extreme north of the Atacama Desert, which has extraordinary habitability conditions characterized by rivers that are reactivated by summer rains in the Andes and valleys with agro-ecological productivity. The Pan American Health Organization determined the end of the presence of the mosquito in 1961 and its reappearance from 2016 in continental Chile. About the methods, the Health Authority established action limits based on the risks presented by these areas in terms of health interest and location, through inspections that allowed the identification of the vulnerability of each area. This was done by means of inspections that made it possible to identify the vulnerability of the sites. The discovery sites were geolocated according to the phenomenology of the species, considering the radius of flight among other phenological characteristics. The results allowed the identification of critical areas for the establishment of focus. The residential typologies of the sites were classified as industrial zones and suburbs in the urban limits with space-time coincidences. During 2016, 56 cases were found in urban and peri-urban areas between May and June. In 2018 there were findings between March-April with 14 cases in industrial and residential areas, while in 2019 there were findings between January-May and December with a total of 27 positive cases in peri-urban areas. In conclusion, there is evidence of a shift in findings from residential areas of paired housing (2016) to industrial areas (2018) and to suburbs in 2019. There is evidence of a deseasonalization in the findings of the mosquito, being a problem that must be controlled 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 take decisions on health management and apply control measures to regulate the accumulation of water. Environmental Education is proposed as a method to promote citizen awareness to face the risks associated with the vector together with government, academic and community coordination, cooperation and collaboration.</p>

2017 ◽  
Vol 7 (2) ◽  
pp. 107
Author(s):  
Budiman Budiman ◽  
Hamidah Hamidah

Dengue Hemorrhagic Fever (DHF) is a severe and potentially lethal dengue virus infection. DHF control measures can be performed on adult mosquitoes or in larvae. Controlling the larval stage can be done by cutting the chain of transmission of dengue disease through containers that made Aedes aegypti mosquitoes laying and breeding. This study aims to determine the preferred container characteristics of larva Aedes aegypti in the work area of Puskesmas Bulili, South Palu District. This research will be carried out in the work area of Puskes Puskesmas Public Health Center by using spot survey method by observing all containers potentially become Aedes aegypti larvae breeding place in research location. The variables under study will be presented in descriptive form by describing the environmental characteristics of containers preferred by Aedes aegypti mosquito larvae ranging from type, base material and container location. The results showed that the type of container favored by Aedes aegypti mosquitoes is the type of bathtub with a base material made of plastic and the location of the container inside the community house.Keywords : DHF, Container, Aedes aegypti


2021 ◽  
Author(s):  
Christian E Gunning ◽  
Amy C Morrison ◽  
Kenichi W Okamoto ◽  
Tom W Scott ◽  
Helvio Astete ◽  
...  

The importance of mosquitoes in human pathogen transmission has motivated major research efforts into mosquito biology in pursuit of more effective vector control measures. Aedes aegypti is a particular concern in tropical urban areas, where it is the primary vector of numerous flaviviruses, including the yellow fever, Zika, and dengue viruses. With an anthropophilic habit, Ae. aegypti prefers houses, human blood meals, and ovipositioning in water-filled containers. We hypothesized that this relatively simple ecological niche should allow us to predict the impacts of insecticidal control measures on mosquito populations. To do this, we use Skeeter Buster 2 (SB2), a stochastic, spatially explicit, mechanistic model of Ae. aegypti population biology. SB2 builds on Skeeter Buster, which reproduced equilibrium dynamics of Ae. aegypti in Iquitos, Peru. Our goal was to predict the response of mosquito populations to perturbations by indoor insecticidal spraying and widespread destructive insect surveys. To evaluate SB2, we conducted two field experiments in Iquitos, Peru: a smaller pilot study in 2013 (S-2013) followed by a larger experiment in 2014 (L-2014). Here, we compare model predictions with (previously reported) empirical results from these experiments. In both simulated and empirical populations, repeated spraying yielded substantial yet temporary reductions in adult densities. The proportional effects of spraying were broadly comparable between simulated and empirical results, but we found noteworthy differences. In particular, SB2 consistently over-estimated the proportion of nulliparous females and the proportion of containers holding immature mosquitoes. We also observed less temporal variation in simulated surveys of adult abundance relative to corresponding empirical observations. Our results indicate the presence of ecological heterogeneities or sampling processes not effectively represented by SB2. Although additional empirical research could further improve the accuracy and precision of SB2, our results underscore the importance of non-linear dynamics in the response of Ae. aegypti populations to perturbations, and suggest general limits to the fine-grained predictability of its population dynamics over space and time.


2019 ◽  
Vol 4 ◽  
pp. 175 ◽  
Author(s):  
Miriam Karuitha ◽  
Joel Bargul ◽  
Joel Lutomiah ◽  
Simon Muriu ◽  
Joseph Nzovu ◽  
...  

Background: Management of arboviruses relies heavily on vector control. Implementation and sustenance of effective control measures requires regular surveillance of mosquito occurrences, species abundance and distribution. The current study evaluated larval habitat diversity and productivity, mosquito species diversity and distribution in selected sites along the coast of Kenya. Methods: A cross-sectional survey of mosquito breeding habitats, species diversity and distribution was conducted in urban, peri-urban and forested ecological zones in Mombasa and Kilifi counties. Results: A total of 13,009 immature mosquitoes were collected from 17 diverse aquatic habitats along the coast of Kenya. Larval productivity differed significantly (F (16, 243) = 3.21, P < 0.0001) among the aquatic habitats, with tyre habitats recording the highest larval population. Culex pipiens (50.17%) and Aedes aegypti (38.73%) were the dominant mosquito species in urban areas, while Ae. vittatus (89%) was the dominant species in forested areas.  In total, 4,735 adult mosquitoes belonging to 19 species were collected in Haller Park, Bamburi, Gede and Arabuko Sokoke forest. Urban areas supported higher densities of Ae. aegypti compared to peri-urban and forest areas, which, on the other hand, supported greater mosquito species diversity. Conclusions: High Ae. aegypti production in urban and peri-urban areas present a greater risk of arbovirus outbreaks. Targeting productive habitats of Aedes aegypti, such as discarded tyres, containers and poorly maintained drainage systems in urban areas and preventing human-vector contact in peri-urban and forested areas could have a significant impact on the prevalence of arboviruses along the coast of Kenya, forestalling the periodic outbreaks experienced in the region.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Abdurrakhman abdurrakhman Abdurrakhman

ABSTRACT : The House index and Container Index in the buffer area of ​​the working area of ​​Balikpapan Sepinggan Airport is still above 1%, so the potential for the spread of dengue disease. Mobilization of people, goods and transportation equipment will increasingly affect the transmission of disease in ports and airports, especially for vector-borne diseases. This study aims to analyze the risk factors associated with larvae density of Aedes aegypti and describe the larvae index in the buffer zone of the Sepinggan Balikpapan Airport This study was a descriptive study with a cross sectional design. The sample in this study was 121 houses with a proportionate stratified random sampling, the research location was in the buffer zone of Sepinggan Balikpapan Airport in November 2018. The variables studied were houses with positive larvae containers, breeding sites and PSN behavior and larvasidation. The data was analyzed using the chi square test. There was a relationship between houses with larvae positive Aedes aegypti, behavior of Mosquito Nest Eradication (PSN) and larvasidation with larvae density of Aedes aegypti but not for breeding sites (p = 0.00 and 95% CI = 0.64), and   (p = 0.00 and 95% CI = 0.34). The description of several Aedes aegypti larvae index, namely House Index (HI) = 57.02%, Container Index (CI) = 24.36%, Bruteau Index (BI) = 148.76, and Flick Free Numbers (ABJ) = 42.98 %. Houses with larvae of Aedes aegypti larvae and PSN and larvasidation behavior were associated with larvae density of Aedes aegypti. The index of HI, CI and BI larvae is of high value so there is a risk of DBD transmission


Author(s):  
А.В. Терешкин ◽  
А.Л. Калмыкова ◽  
Т.А. Андрушко

Вертикальное озеленение с участием различных видов лиан в современных условиях имеет важное эстетическое и санитарно-гигиеническое значение. Особо актуально решение вопросов обогащения флоры городских территорий лианами в степных районах в связи с бедным видовым составом и резким ухудшением экологической ситуации. Объектами исследований являлись 7 видов лиан, различных жизненных форм (однолетние, многолетние), произрастающие в населенных пунктах Саратовской области (Аткарск, Саратов). Цель исследований – изучение эколого-биологических особенностей и мелиоративных свойств лиан и выявление перспектив их использования в вертикальном озеленении селитебных территорий Саратовской области. В ходе исследования видового состава, были выявлены наиболее популярные виды однолетних лиан: ипомея красно-голубая (Ipomea tricolor (L.) Roth) и ипомея пурпурная (Ipomea purpurea (L.) Roth), горошек душистый (Lathyrus edoratus L.), настурция (Tropacolum peregrinum L.) и фасоль огненно-красная (Phaseolus coccineus). Большинство (70%) из них произрастают в местах ограниченного пользования. Изученные виды лиан в исследуемых регионах достигают средних природных показателей (при наличии надлежащего ухода), обладают хорошими показателями жизненного состояния, обильно цветут и плодоносят. При воздействии токсикантами различной концентрации на листовые пластинки лиан установлено их степень устойчивости. Выявлено, что однолетние лианы лучше использовать в декоративных целях, а не в санитарно-гигиенических. Сравнительная оценка однолетних видов с многолетними лианами (девичий виноград пятилисточковый и клематис тангутский) показывает устойчивость многолетних видов (в среднем на 3 балла - 40%). Разработаны варианты декоративных композиций с участием травянистых лиан. По степени декоративности выделены однолетние лианы – Ipomea tricolor, I. purpurea (37 – 41 балл), средней степенью отличаются – Lathyrus edoratus (33 балла), Tropacolum peregrinum (30 баллов) и Phaseolus coccineus (20 – 27 баллов). Преимущество многолетних лиан заключается в их устойчивости к резким изменениям климатических условий (на 40 %) по сравнению с однолетними формами. Поэтому они более предпочтительны для озеленения городской среды. Для усиления декоративного эффекта в сезонном аспекте рекомендуются сочетать расширение видового и формового разнообразия растений (многолетние и однолетние лианы, древесно-кустарниковая, цветочная растительность). Установлено, что природно-климатические условия зоны степи и лесостепи в пределах Саратовской области являются достаточно благоприятными для нормального роста и развития древесно-кустарниковой растительности, в том числе травянистых лиан. Таким образом, обоснованное применение древесных лиан в комплексе с традиционными видами насаждений позволит создать комфортные условия проживания населения, регулировать оптимальный температурный баланс и создавать благоприятные микроклиматические условия. Vertical gardening with different types of vines in modern conditions is important aesthetic and sanitary-hygienic value. It is especially important to address the issues of enrichment of the flora of urban areas with vines in the steppe regions due to poor species composition and a sharp deterioration of the ecological situation. The objects of research were 7 species of lianas, various life forms (annual, perennial), growing in the settlements of the Saratov region (Atkarsk, Saratov). The aim of the research is to study the ecological and biological features and reclamation properties of vines and identify the prospects for their use in vertical gardening residential areas of the Saratov region. In the study, species composition was the most popular species of annual vines: morning glory red-blue (Ipomea tricolor (L.) Roth) and purple morning glory (Ipomea purpurea (L.) Roth), the fragrant pea (Lathyrus edoratus L.), nasturtium (Tropacolum peregrinum L.) and runner beans (Phaseolus coccineus). Most (70%) of them grow in restricted areas. Studied species of vines in the study regions reach average natural performance (with proper care), have good indicators of vital condition, bloom abundantly and bear fruit. When exposed to toxicants of different concentrations on the leaf blades of vines established their degree of stability. It was revealed that the annual vines are better used for decorative purposes, and not in the sanitary-hygienic. A comparative assessment of annual species with perennial vines (maiden grapes and clematis Tangut) shows the stability of perennial species (an average of 3 points-40%). The options and decorative compositions with the participation of herbaceous vines. According to the degree of decoration of the allocated annual vine – Ipomea tricolor, I. purpurea (37 – 41 points), the average degree of differ – Lathyrus edoratus (33 points), Tropacolum peregrinum (30 points) and Phaseolus coccineus (20 to 27 points). The advantage of perennial vines is their resistance to sudden changes in climatic conditions (40 %) compared to annual forms. Therefore, they are more preferable for greening the urban environment. To enhance the decorative effect in the seasonal aspect, it is recommended to combine the expansion of species and form diversity of plants (perennial and annual lianas, tree and shrub, floral vegetation). It is established that the climatic conditions of the steppe and forest-steppe zone within the Saratov region are quite favorable for the normal growth and development of tree and shrub vegetation, including herbaceous lianas. Thus, the reasonable use of wood vines in combination with traditional types of plantings will create comfortable living conditions for the population, regulate the optimal temperature balance and create favorable microclimatic conditions.


2020 ◽  
Author(s):  
Lukman Olagoke ◽  
Ahmet E. Topcu

BACKGROUND COVID-19 represents a serious threat to both national health and economic systems. To curb this pandemic, the World Health Organization (WHO) issued a series of COVID-19 public safety guidelines. Different countries around the world initiated different measures in line with the WHO guidelines to mitigate and investigate the spread of COVID-19 in their territories. OBJECTIVE The aim of this paper is to quantitatively evaluate the effectiveness of these control measures using a data-centric approach. METHODS We begin with a simple text analysis of coronavirus-related articles and show that reports on similar outbreaks in the past strongly proposed similar control measures. This reaffirms the fact that these control measures are in order. Subsequently, we propose a simple performance statistic that quantifies general performance and performance under the different measures that were initiated. A density based clustering of based on performance statistic was carried out to group countries based on performance. RESULTS The performance statistic helps evaluate quantitatively the impact of COVID-19 control measures. Countries tend show variability in performance under different control measures. The performance statistic has negative correlation with cases of death which is a useful characteristics for COVID-19 control measure performance analysis. A web-based time-line visualization that enables comparison of performances and cases across continents and subregions is presented. CONCLUSIONS The performance metric is relevant for the analysis of the impact of COVID-19 control measures. This can help caregivers and policymakers identify effective control measures and reduce cases of death due to COVID-19. The interactive web visualizer provides easily digested and quick feedback to augment decision-making processes in the COVID-19 response measures evaluation. CLINICALTRIAL Not Applicable


2021 ◽  
Vol 13 (12) ◽  
pp. 6930
Author(s):  
Shinsuke Kyoi

This study evaluates people’s preferences regarding the proximity of their residence to agricultural urban green infrastructure (UGI), such as agricultural land and satoyama, and discusses the availability of these types of land as UGI. UGI is vital for reducing the negative environmental impacts of urban areas, as these impacts are too large to ignore. In this study, we conducted an online survey and a choice experiment to investigate people’s perceptions regarding the proximity of their residence to agricultural UGI (AUGI). The respondents of the choice experiment were 802 inhabitants of Ishikawa Prefecture, Japan, which has rich agricultural resources. To examine explicitly the spatial autocorrelation of people’s preferences, in this study, we used the spatial econometrics method. The main empirical findings are that people prefer agricultural land far away from their residence—more than 1000 m, not within 1000 m—which reflects the not-in-my-backyard phenomenon. Meanwhile, people’s preferences regarding proximity to satoyama are complicated and their preferences are positively spatially autocorrelated. The results indicate that policymakers and urban planners should manage and provide AUGI far away from residential areas; otherwise, they must address people’s avoidance of neighboring AUGI.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Camila Lorenz ◽  
Marcia C. Castro ◽  
Patricia M. P. Trindade ◽  
Maurício L. Nogueira ◽  
Mariana de Oliveira Lage ◽  
...  

AbstractIdentifying Aedes aegypti breeding hotspots in urban areas is crucial for the design of effective vector control strategies. Remote sensing techniques offer valuable tools for mapping habitat suitability. In this study, we evaluated the association between urban landscape, thermal features, and mosquito infestations. Entomological surveys were conducted between 2016 and 2019 in Vila Toninho, a neighborhood of São José do Rio Preto, São Paulo, Brazil, in which the numbers of adult female Ae. aegypti were recorded monthly and grouped by season for three years. We used data from 2016 to 2018 to build the model and data from summer of 2019 to validate it. WorldView-3 satellite images were used to extract land cover classes, and land surface temperature data were obtained using the Landsat-8 Thermal Infrared Sensor (TIRS). A multilevel negative binomial model was fitted to the data, which showed that the winter season has the greatest influence on decreases in mosquito abundance. Green areas and pavements were negatively associated, and a higher cover of asbestos roofs and exposed soil was positively associated with the presence of adult females. These features are related to socio-economic factors but also provide favorable breeding conditions for mosquitos. The application of remote sensing technologies has significant potential for optimizing vector control strategies, future mosquito suppression, and outbreak prediction.


Author(s):  
Ruzhen Luo ◽  
Chunmei Zhang ◽  
Yanhui Liu

In China, many young and middle-aged rural residents move to urban areas each year. The rural elderly are left behind. The number of the rural left-behind elderly is increasing with urbanization, but it is unclear which indicators can be used to assess their health condition. The health risk assessment index system was developed to improve the health level of the rural left-behind elderly. A two-round web-based Delphi process was used to organize the recommendations from fifteen Chinese experts in geriatrics, health management, social psychology who participated in this study. Meaningfulness, importance, modifiability, and comprehensive value of the health risk assessment indicators in the index system were evaluated. The effective recovery rates of the two-round Delphi were 86.67% and 92.31%, respectively. The judgement coefficient and the authority coefficient were 0.87 and 0.82, respectively. The expert familiarity was 0.76. Ultimately, the health risk assessment index system for the rural left-behind elderly consisted of five first-level indicators, thirteen second-level indicators, and sixty-six third-level indicators. The final indicators can be used to evaluate the health of the rural left-behind elderly and provide the basis for additional health risk interventions.


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