Search bioRxiv⌕ Search

Biology subjects

Almiron, W. R.

Publications and source records attributed to Almiron, W. R..

3 recordsLinked to original sources

Systematic literature review about educational interventions evaluated through entomological indices or practices to prevent the presence of or eliminate breeding sites of Aedes

BackgroundCommunity participation is a critical element in the management of Aedes breeding sites. Many educational interventions have been conducted to encourage prevention and elimination of breeding sites among different community actors, such as government-run programs for vector surveillance aimed at preventing and eliminating breeding sites at the household level within a community. Getting people involved in prevention and elimination of vector breeding sites in their communities requires communication and social mobilization strategies to promote and reinforce those prevention actions that, in turn, should be effective from the entomological standpoint. Methodology/Principal FindingsArticles published in English, Spanish, and Portuguese, were reviewed to assess whether educational interventions targeting Aedes were effective in reducing entomological indicators or in improving practices to prevent the presence of or eliminate breeding sites. The most widely used indicators were the larval indices, and the practices to reduce/eliminate breeding sites. We found that using a community-based approach adapted to the eco-epidemiological and sociocultural scenarios explain the reduction of entomological indicators by educational interventions. Conclusions/SignificanceThose who design or implement educational interventions should strengthen the evaluation of those interventions using qualitative approaches that provide a more complete picture of the social context and barriers/facilitators to implementing vector control. Engaging school children in cross-sectorial collaboration involving the health and education spheres promotes the participation of the community in vector surveillance and reduces the risk of arboviral disease transmission. Author summaryDengue, Zika, and chikungunya are mosquito-borne diseases that represent a major global public health problem. These diseases are transmitted mainly through the bite of the Aedes aegypti vector mosquito and, to a lesser extent, Ae. albopictus. Getting people involved in prevention and elimination of mosquitos in their communities requires communication and social mobilization strategies to promote and reinforce those prevention actions that, in turn, should be effective from the entomological standpoint. The success of vector control programs has been demonstrated to lie in a comprehensive effort involving key community participation and intersectoral alliances. In addition, the participation of schoolchildren to mobilize their families in the prevention of breeding sites and the management of mosquito populations is recommended. In this article, we proposed to conduct a systematic review of scientific publications that evaluate the effects of educational interventions on Aedes through entomological indicators. As a result, we obtained only 26 articles that evaluated the efficacy of educational interventions in reducing vector populations out of 732 articles reviewed. The selected articles were published in both English and Spanish, and to a lesser extent in Portuguese, which highlights the importance of avoiding language bias in systematic reviews. As a conclusion of our work, we can mention that the interventions that incorporated the social context and the barriers/facilitators for the implementation of vector control were the most successful. In addition, we emphasize the importance of involving schoolchildren to promote community participation in vector surveillance.

scientific communication and education↗

A decade of arbovirus emergence in the temperate southern cone of South America: dengue, Aedes aegypti and climate dynamics in Cordoba, Argentina

BackgroundArgentina is located at the southern temperate range of arboviral transmission by the mosquito Aedes aegypti and has experienced a rapid increase in disease transmission in recent years. Here we present findings from an entomological surveillance study that began in Cordoba, Argentina, following the emergence of dengue in 2009. MethodsFrom 2009 to 2017, larval surveys were conducted monthly, from November to May, in 600 randomly selected households distributed across the city. From 2009 to 2013, ovitraps (n=177) were sampled weekly to monitor the oviposition activity of Ae. aegypti. We explored seasonal and interannual dynamics of entomological variables and dengue transmission. Cross correlation analysis was used to identify significant lag periods. ResultsAedes aegypti were detected over the entire study period, and abundance peaked during the summer months (January to March). We identified a considerable increase in the proportion of homes with juvenile Ae. aegypti over the study period (from 5.7% of homes in 2009-10 to 15.4% of homes in 2016-17). Aedes aegypti eggs per ovitrap and larval abundance were positively associated with temperature in the same month. Autochthonous dengue transmission peaked in April, following a peak in imported dengue cases in March; autochthonous dengue was not positively associated with vector or climate variables. ConclusionsThis longitudinal study provides insights into the complex dynamics of arbovirus transmission and vector populations in a temperate region of arbovirus emergence. Our findings suggest that Cordoba is well suited for arbovirus disease transmission, given the stable and abundant vector populations. Further studies are needed to better understand the role of regional human movement. Author summaryThere is an increasing risk of arbovirus transmission in temperate regions. Argentina is located at the southern range of dengue virus transmission by the Aedes aegypti mosquito. In the last decade, epidemics of dengue fever have emerged for the first time in the city of Cordoba, Argentina. We present the study design and findings from an entomological surveillance study in Cordoba, which began following the emergence of dengue in 2009. We found that Ae. aegypti were most abundant from January to March, followed by a peak in local dengue transmission in April. Over the study period, we noted a considerable increase in the proportion of homes with Ae. aegypti. Vector indices were positively associated with warmer temperatures, which have been increasing in this region. However, the timing of local dengue transmission appears to be driven by the appearance of imported dengue cases associated with human movement. These results highlight the important role of long term surveillance studies in areas of disease emergence.

ecology↗

Temporal models using environmental variables to predict Aedes aegypti oviposition activity in a temperate region of Argentina.

Environmental variables are some of the factors that more impact on Aedes aegypti, vector of Dengue, Chikungunya and Zika viruses. In this study, the Ae. aegypti oviposition activity was related to satellite and meteorological variables, in Cordoba City (Argentina). Eggs were collected using ovitraps placed throughout the city from 2009 to 2012, replaced them weekly. Generalized Linear Mixed Models were developed with negative binomial distributions of errors, modeling average number of eggs collected weekly as a function of satellite and meteorological variables with time lags. The best model included a vegetation index, vapor pressure of water, precipitation and photoperiod, lagged between 3 and 4 weeks. By each increment unit in vegetation index, vapor pressure (hPa) and light hour, the average number of eggs increases by 72%, 20% and 29%, respectively, in the following 3 or 4 weeks. In addition, the average number of eggs decreases a 50% in the following month by each millimeter of rain. The results evince the relevant importance of the vegetation, maybe due to the shade that provide to the containers as breeding habitat of this species and the shelter for adults. On the other hand, the negative effect of precipitation could be a consequence of abundant rainfalls that fulfill containers avoiding females to lay eggs in there. Although no significant effect of the photoperiod on the vector abundance has been detected in the north of the country, in Cordoba City an important effect is observed when it is presented together with other variables, producing different effects of these variables in different regions. Lastly, it is necessary to emphasize the importance of the minimum temperature in temperate zones, since it would be a limiting factor that prevents the Ae. aegypti oviposition activity.

ecology↗