scholarly journals Challenges for the Introduction and Evaluation of the Impact of Innovative Aedes aegypti Control Strategies

Author(s):  
Héctor Gómez-Dantés ◽  
Norma Pavía-Ruz ◽  
Fabián Correa-Morales ◽  
Abdiel Martín-Park ◽  
Gonzalo Vázquez-Prokopec ◽  
...  
Author(s):  
Whitney Holeva-Eklund ◽  
Timothy Behrens ◽  
Crystal Hepp

Background: Aedes aegypti mosquitoes are primary vectors of dengue, yellow fever, chikungunya and Zika viruses. A. aegypti is highly anthropophilic and relies nearly exclusively on human blood meals and habitats for reproduction. Socioeconomic factors may influence the spread of A. aegypti due to their close relationship with humans. This paper describes and summarizes the published literature on how socioeconomic variables influence the distribution of A. aegypti mosquitoes in the mainland United States. Methods: A comprehensive search of PubMed/Medline, Scopus, Web of Science, and EBSCO Academic Search Complete through June 12, 2019 was used to retrieve all articles published in English on the association of socioeconomic factors and the distribution of A. aegypti mosquitoes. Articles were screened for eligibility using the process described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: Initially, 3,493 articles were identified through the database searches and previously known literature. After checking for duplicates, 2,145 articles remained. These articles were screened for eligibility using their titles and abstracts, and 2,098 articles were excluded for not meeting the eligibility criteria. Finally, the full text for each of the remaining articles (n = 38) was read to determine eligibility. Through this screening process, 11 articles were identified for inclusion in this review. Conclusions: The findings for these 11 studies revealed inconsistent relationships between the studied socioeconomic factors and the distribution and abundance of A. aegypti. The findings of this review suggest a gap in the literature and understanding of the influence of anthropogenic factors on the distribution of A. aegypti that could hinder efforts to implement effective public health prevention and control strategies should a disease outbreak occur.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
ECR Dos Santos ◽  
S C Cohren ◽  
R G R Costa

Abstract In recent decades, the diseases caused by the Aedes aegypti have been responsible for a high number of mortality cases worldwide, making it a serious public health problem. This article describes the diseases prevalence caused by Aedes Aegypti: Dengue, Zika and Chikungunya, in the Sanitary Districts of city of São Luis - in the state of Maranhão in Brazil, from 2007 to 2017. This study is based on data analysis recorded by the Information System on Diseases of Compulsory Declaration (SINAN). From 2007 to 2017, 25,124 dengue cases were reported in the city of São Luís, there was an increase in prevalence in 2011 with 5,378 cases, about 53% of recorded cases in the State of Maranhão, probably due to the presence of new circulating serotypes: DENV-1; DENV-2 AND DENV-4, with 14 deaths. Female gender predominated among registered cases, and the age group with the highest number of reported cases was 20 to 39 years. In 2015 started the first reports of the Zika virus and chikungunya, both with epidemiological peak in 2016. São Luis has 229 urban neighborhoods and 165 rural neighborhoods distributed in seven health districts. The Bequimão Sanitary District in the urban area of city of São Luis consists of 64 neighborhoods, has recorded a higher number of dengue cases, 6,239 cases. From 2015 to 2017, it reported 864 cases of Zika virus and 407 cases of chikungunya. It is concluded that the prevalence of diseases, caused by Aedes aegypti, shows endemic variation, in the three arboviruses, related to population density and local sanitary conditions, characteristics which are present in the Sanitary District of Bequimão where it's registered a lack of sanitary infrastructure and intermittent water supply, the study notes the need to adopt control strategies of sanitary officers, and agencies and awareness of the population. Key messages The research produced knowledge about the impact of urbanization on the epidemiology of dengue, zika and chikungunya, enabling knowledge of the sanitation conditions of the studied city. The knowledge produced by the research substantiates strategies and actions to combat the vector by the health authorities and conscious action of the population.


2018 ◽  
Author(s):  
Irina Maljkovic Berry ◽  
Fredrick Eyase ◽  
Simon Pollett ◽  
Samson Limbaso Konongoi ◽  
Katherine Figueroa ◽  
...  

AbstractBackgroundIn 2016, a chikungunya virus (CHIKV) outbreak was reported in Mandera, Kenya. This was the first major CHIKV outbreak in the country since the global re-emergence of this virus, which arose as an initial outbreak in Kenya in 2004. Therefore, we collected samples and sequenced viral genomes from the 2016 Mandera outbreak.Methodology/Principal FindingsAll Kenyan genomes contained two mutations, E1:K211E and E2:V264A, recently reported to have an association with increased infectivity, dissemination and transmission in the Aedes aegypti (Ae. aegypti) vector. Phylogeographic inference of temporal and spatial virus relationships using Bayesian approaches showed that this Ae. aegypti adapted strain emerged within the East, Central, and South African (ECSA) lineage of CHIKV between 2005 and 2008, most probably in India. It was also in India where the first large outbreak caused by this strain appeared, in New Delhi, 2010. More importantly, our results also showed that this strain is no longer contained to India, and that it has more recently caused several major outbreaks of CHIKV, including the 2016 outbreaks in India, Pakistan and Kenya, and the 2017 outbreak in Bangladesh. In addition to its capability to cause large outbreaks in different regions of the world, this CHIKV strain has the capacity to replace less adapted wild type strains in Ae. aegypti-rich regions. Indeed, all the latest full CHIKV genomes of the ECSA Indian Ocean Lineage (IOL), from the regions of high Ae. aegypti prevalence, carry these two mutations, including samples collected in Japan, Australia, and China.Conclusions/SignificanceOur results point to the importance of continued genomic-based surveillance of this strain’s global spread, and they prompt urgent vector competence studies in Asian and African countries, in order to assess the level of vector receptiveness, virus transmission, and the impact this might have on this strain’s ability to cause major outbreaks.Author summaryChikungunya virus (CHIKV) causes a debilitating infection with high fever, intense muscle and bone pain, rash, nausea, vomiting and headaches, and persistent and/or recurrent joint pains for months or years after contracting the virus. CHIKV is spread by two mosquito vectors, Aedes albopictus and Aedes aegypti, with increased presence around the globe. In this study, we report global spread of a CHIKV strain that carries two mutations that have been suggested to increase this virus’ ability to infect the Aedes aegypti mosquito, as well as to increase CHIKV’s ability to be transmitted by this vector. We show that this strain appeared sometime between 2005 and 2008, most probably in India, and has now spread to Africa, Asia, and Australia. We show that this strain is capable of driving large outbreaks of CHIKV in the human population, causing recent major outbreaks in Kenya, Pakistan, India and Bangladesh. Thus, our results stress the importance of monitoring this strain’s global spread, as well as the need of improved vector control strategies in the areas of Aedes aegypti prevalence.


2021 ◽  
Vol 15 (9) ◽  
pp. e0009815
Author(s):  
Garrett P. League ◽  
Ethan C. Degner ◽  
Sylvie A. Pitcher ◽  
Yassi Hafezi ◽  
Erica Tennant ◽  
...  

Background Aedes aegypti mosquitoes are globally distributed vectors of viruses that impact the health of hundreds of millions of people annually. Mating and blood feeding represent fundamental aspects of mosquito life history that carry important implications for vectorial capacity and for control strategies. Females transmit pathogens to vertebrate hosts and obtain essential nutrients for eggs during blood feeding. Further, because host-seeking Ae. aegypti females mate with males swarming near hosts, biological crosstalk between these behaviors could be important. Although mating influences nutritional intake in other insects, prior studies examining mating effects on mosquito blood feeding have yielded conflicting results. Methodology/Principal findings To resolve these discrepancies, we examined blood-feeding physiology and behavior in virgin and mated females and in virgins injected with male accessory gland extracts (MAG), which induce post-mating changes in female behavior. We controlled adult nutritional status prior to blood feeding by using water- and sugar-fed controls. Our data show that neither mating nor injection with MAG affect Ae. aegypti blood intake, digestion, or feeding avidity for an initial blood meal. However, sugar feeding, a common supplement in laboratory settings but relatively rare in nature, significantly affected all aspects of feeding and may have contributed to conflicting results among previous studies. Further, mating, MAG injection, and sugar intake induced declines in subsequent feedings after an initial blood meal, correlating with egg production and laying. Taking our evaluation to the field, virgin and mated mosquitoes collected in Colombia were equally likely to contain blood at the time of collection. Conclusions/Significance Mating, MAG, and sugar feeding impact a mosquito’s estimated ability to transmit pathogens through both direct and indirect effects on multiple aspects of mosquito biology. Our results highlight the need to consider natural mosquito ecology, including diet, when assessing their physiology and behavior in the laboratory.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3274
Author(s):  
Jose Rueda Torres ◽  
Zameer Ahmad ◽  
Nidarshan Veera Kumar ◽  
Elyas Rakhshani ◽  
Ebrahim Adabi ◽  
...  

Future electrical power systems will be dominated by power electronic converters, which are deployed for the integration of renewable power plants, responsive demand, and different types of storage systems. The stability of such systems will strongly depend on the control strategies attached to the converters. In this context, laboratory-scale setups are becoming the key tools for prototyping and evaluating the performance and robustness of different converter technologies and control strategies. The performance evaluation of control strategies for dynamic frequency support using fast active power regulation (FAPR) requires the urgent development of a suitable power hardware-in-the-loop (PHIL) setup. In this paper, the most prominent emerging types of FAPR are selected and studied: droop-based FAPR, droop derivative-based FAPR, and virtual synchronous power (VSP)-based FAPR. A novel setup for PHIL-based performance evaluation of these strategies is proposed. The setup combines the advanced modeling and simulation functions of a real-time digital simulation platform (RTDS), an external programmable unit to implement the studied FAPR control strategies as digital controllers, and actual hardware. The hardware setup consists of a grid emulator to recreate the dynamic response as seen from the interface bus of the grid side converter of a power electronic-interfaced device (e.g., type-IV wind turbines), and a mockup voltage source converter (VSC, i.e., a device under test (DUT)). The DUT is virtually interfaced to one high-voltage bus of the electromagnetic transient (EMT) representation of a variant of the IEEE 9 bus test system, which has been modified to consider an operating condition with 52% of the total supply provided by wind power generation. The selected and programmed FAPR strategies are applied to the DUT, with the ultimate goal of ascertaining its feasibility and effectiveness with respect to the pure software-based EMT representation performed in real time. Particularly, the time-varying response of the active power injection by each FAPR control strategy and the impact on the instantaneous frequency excursions occurring in the frequency containment periods are analyzed. The performed tests show the degree of improvements on both the rate-of-change-of-frequency (RoCoF) and the maximum frequency excursion (e.g., nadir).


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xi Huo ◽  
Jing Chen ◽  
Shigui Ruan

Abstract Background The COVID-19 outbreak in Wuhan started in December 2019 and was under control by the end of March 2020 with a total of 50,006 confirmed cases by the implementation of a series of nonpharmaceutical interventions (NPIs) including unprecedented lockdown of the city. This study analyzes the complete outbreak data from Wuhan, assesses the impact of these public health interventions, and estimates the asymptomatic, undetected and total cases for the COVID-19 outbreak in Wuhan. Methods By taking different stages of the outbreak into account, we developed a time-dependent compartmental model to describe the dynamics of disease transmission and case detection and reporting. Model coefficients were parameterized by using the reported cases and following key events and escalated control strategies. Then the model was used to calibrate the complete outbreak data by using the Monte Carlo Markov Chain (MCMC) method. Finally we used the model to estimate asymptomatic and undetected cases and approximate the overall antibody prevalence level. Results We found that the transmission rate between Jan 24 and Feb 1, 2020, was twice as large as that before the lockdown on Jan 23 and 67.6% (95% CI [0.584,0.759]) of detectable infections occurred during this period. Based on the reported estimates that around 20% of infections were asymptomatic and their transmission ability was about 70% of symptomatic ones, we estimated that there were about 14,448 asymptomatic and undetected cases (95% CI [12,364,23,254]), which yields an estimate of a total of 64,454 infected cases (95% CI [62,370,73,260]), and the overall antibody prevalence level in the population of Wuhan was 0.745% (95% CI [0.693%,0.814%]) by March 31, 2020. Conclusions We conclude that the control of the COVID-19 outbreak in Wuhan was achieved via the enforcement of a combination of multiple NPIs: the lockdown on Jan 23, the stay-at-home order on Feb 2, the massive isolation of all symptomatic individuals via newly constructed special shelter hospitals on Feb 6, and the large scale screening process on Feb 18. Our results indicate that the population in Wuhan is far away from establishing herd immunity and provide insights for other affected countries and regions in designing control strategies and planing vaccination programs.


2020 ◽  
Vol 1 (1) ◽  
pp. 20-29
Author(s):  
Hussaini Ojagefu Adamu ◽  
Rahimat Oshuwa Hussaini ◽  
Cedric Obasuyi ◽  
Linus Irefo Anagha ◽  
Gabriel Oscy Okoduwa

AbstractMastitis is a disease of livestock that directly impede livestock production and thus hindering the socio-ecological development of sub-Saharan Africa. Studies have estimated the prevalence of this disease in 30% of Africa countries, with Ethiopia having the highest prevalence. The coverage is low, despite the wide livestock and dairy farms distribution in Africa. Furthermore, estimated economic losses due to the impact of mastitis are lacking in Nigeria. The disease is endemic in Nigeria as indicated by the available data and there are no proposed management plans or control strategies. This review is thus presented to serve as a wakeup call to all parties involved to intensify efforts towards the diagnosis, control, and management of the disease in Nigeria.


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.


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