Survival of larvivorous fish used for biological control of Aedes aegypti (Diptera: Culicidae) combined with different larvicides

A Systematic Review of Mathematical Models of Dengue Transmission and Vector Control: 2010-2020

Vector control methods are considered effective in averting dengue transmission. However, several factors may modify their impact. Of these controls, chemical methods, in the long run, may increase mosquitoes' resistance to chemicides, thereby decreasing control efficacy. The biological methods, which may be self-sustaining and very effective, could be hampered by seasonality or heatwaves (resulting in, e.g., loss of Wolbachia infection). The environmental methods that could be more effective than the chemical methods are under-investigated. In this study, a systematic review is conducted to explore the present understanding of the effectiveness of vector control approaches via dengue transmission models.

Increasing Dengue Burden and Severe Dengue Risk in Bangladesh: An Overview

Dengue is a prevalent and rapidly spreading mosquito-borne viral disease affecting humans. The geographic range of dengue is expanding, and much like in many other tropical regions of the world, dengue has become a major public health issue in Bangladesh. Until a large epidemic dengue outbreak in 2000, sporadic outbreaks have occurred in Bangladesh since 1964. After 2000, varying intensities of dengue activity were observed each year until 2018. However, in 2019, Bangladesh experienced the largest dengue epidemic in its history, with 101,354 dengue cases and 164 dengue-related deaths. Notably, this outbreak occurred in many regions that were previously considered free of the disease. As of 10 December 2022, a total of 60,078 dengue cases and 266 dengue-related deaths were reported in Bangladesh, with the 2022 outbreak being the second largest since 2000. There is an increased genetic diversity of the dengue virus (DENV) in Bangladesh and all four DENV serotypes are prevalent and co-circulating, which increases the risk for severe dengue owing to the antibody-dependent enhancement effect. Vector control remains the mainstay of dengue outbreak prevention; however, the vector control programs adopted in Bangladesh seem inadequate, requiring improved vector control strategies. In this review, we provide an overview of the epidemiology of DENV infection and the risks for a severe dengue outbreak in Bangladesh. Additionally, we discuss different dengue vector control strategies, from which the most suitable and effective measures can be applied in the context of Bangladesh for tackling future dengue epidemics.

Ações educativas de enfrentamento ao Aedes Aegypti: revisão integrativa

Resumo Objetivou sintetizar os estudos, publicados na literatura cientifica, que abordem estratégias de enfrentamento às arboviroses mediante ações educativas. Os dados foram coletados nas bases de dados: LILACS, BDENF e MEDLINE utilizando os descritores “Educação em Saúde” e “Aedes” empregando o operador booleano “AND”. Foram encontrados 242 estudos, dos quais após aplicação dos critérios de inclusão e exclusão, 14 foram incluídos na revisão. Os dados foram analisados utilizando a abordagem qualitativa. Foram identificadas quatro categorias: ações de enfrentamento vetorial mediante capacitação da comunidade; mobilização social em torno do combate às arboviroses; combate vetorial a partir de ações educativas associadas ao uso de controle biológico; ações integradas de enfrentamento às arboviroses. Infere-se que a educação em saúde é um elemento indispensável para o enfrentamento às arboviroses que deverá ser implementada de forma conjunta e articuladas às demais estratégia de combate vetorial.

Dengue: 30 years of cases in an endemic area

The present study aimed to review literature on studies of dengue cases conducted over 30 years in the state of Ceará.

Between November 2015 and January 2016, articles published in Portuguese and English in 7 databases were searched using keywords and a Boolean operator. A total of 191 articles were identified in the databases; 133 were excluded according to the exclusion criteria, and 58 were included in the study.

Of the 58 articles analyzed, 6 reported data from Brazil; including the Northeast region and the state of Ceará; 41 reported data for only the city of Fortaleza; 7 reported data for the state of Ceará; 4 reported data for cities in the interior of the state; and 3 included only children. The studies adopted different approaches and focused on different aspects of the disease. Study outcomes included the identification of serological, epidemiological, clinical, and laboratory characteristics; potential larvicides and biological predators of mosquitoes; potential antiviral agents; vector density characteristics; and educational dengue prevention and control strategies. Additionally, one vaccine trial was included.

Although studies on dengue in the state of Ceará are scarce, they are encompassing, including several lines of research, and the number of studies and reports on dengue in the state of Ceará continues to increase.

Meta-analysis of studies on chemical, physical and biological agents in the control of Aedes aegypti

Background

Aedes aegypti is a vector of international concern because it can transmit to humans three important arboviral diseases: yellow fever, dengue and chikungunya. Epidemics that are repeated year after year in a variety of urban centers indicate that there are control failures, allowing the vector to continue expanding.

Methods

To identify the most effective vector control strategies and the factors that contributed to the success or failure of each strategy, we carried out a systematic review with meta-analysis of articles published in 12 databases, from 1974 to the month of December 2013. We evaluated the association between the use of whatever chemical substance, mechanical agent, biological or integrated actions against A. aegypti and the control of the vector, as measured by 10 indicators.

Results

We found 2,791 articles, but after careful selection, only 26 studies remained for analysis related to control interventions implemented in 15 countries, with 5 biological, 5 chemical, 3 mechanical and 13 integrated strategies. The comparison among all of them, indicated that the control of A. aegypti is significantly associated with the type of strategy used, and that integrated interventions consist of the most effective method for controlling A. aegypti.

Conclusions

The most effective control method was the integrated approach, considering the influence of eco-bio-social determinants in the virus-vector-man epidemiological chain, and community involvement, starting with community empowerment as active agents of vector control.