Dengue Control Research Articles

Epidemiological Characteristics of Dengue Fever - China, 2005-2023.

The global incidence of dengue fever has increased significantly over the past two decades, and China faces a significant upward trend in dengue control challenges. Data were obtained from China's NNDRS from 2005 to 2023. Joinpoint regression software was used to analyze temporal trends, while SaTScan software was used to analyze spatial, seasonal, and spatiotemporal distributions. ArcGIS software was used to visualize clusters. A total of 117,892 dengue cases were reported from 2005 to 2023, with significant fluctuation in annual reported cases. Dengue was not endemic in China. Autochthonous outbreaks most likely occurred in the southwestern, southeastern coastal, and inland areas of China. These outbreaks have occurred between June and November, generally peaking in September or October, around epidemiological week (EW) 40. Dengue challenges in China are increasing. Timely case monitoring, proactive control interventions, and staff mobilization should be implemented before June to ensure a timely response to autochthonous outbreaks.

Awareness of Dengue Disease among Female Community Health Volunteers of Sainamina Municipality, Nepal

Dengue is a mosquito-borne viral infection that is a major public health problem in Nepal. Female community health volunteers play a vital role in dengue prevention and control by providing health education and services to the community. This study aimed to provide a comprehensive understanding of the level of dengue awareness among female community health volunteers in Sainamina Municipality, Nepal. This study involved a cross-sectional survey of 50 female community health volunteers aged 20 and above, actively engaged in health-related activities in Sainamina Municipality. A structured questionnaire was used to gather information on their knowledge of dengue transmission, symptoms, preventive measures, and available treatments. The findings revealed that 98 percentage of the female community health volunteers had a general knowledge of dengue, but there was some confusion regarding the specific mode of transmission. Their knowledge about the signs and symptoms, transmission routes, and preventive measures was inadequate. Only 74 percentage identified that dengue is transmitted through the bite of an infected Aedes mosquito. Additionally, 48 percentage of respondents were able to identify the Aedes mosquito, and 36 percentage knew that there was no specific medicine for dengue patients. Targeted efforts are needed to address the areas of confusion among the female community health volunteers and enhance awareness of comprehensive prevention strategies. It is recommended to conduct training, provide educational materials, and encourage them to share their knowledge with their communities to improve dengue awareness and prevention efforts.

COMMUNITY PERSPECTIVE ON PREVENTION AND CONTROL STRATEGIES OF DENGUE INFECTION IN MALAYSIA

Dengue is a vector-borne disease caused by a rapidly-spreading virus. Dengue vector control is considered the most efficient way for limiting and curbing the spread of the dengue virus. This study aimed to determine the perception of the Malaysian community towards control measures of mosquitoes and the utilisation of biocontrol. A total of 402 respondents in Putrajaya and Selangor participated in the survey. The questionnaire was broadly divided into three sections: Knowledge of biological control, respondent profiles, knowledge of dengue fever prevention, and the utilisation of insecticide for mosquito control. Most of the respondents (83.0%) expressed concern regarding the effects of fogging activities on their health, whereas slightly more than half (56.0%) posited that fogging activities may have adverse environmental effects. The fogging method was reported as the most frequent method (29.2%) employed in controlling the mosquito population. Biocontrol with guppy fish scored (15.5%) and ABATE (mosquito larvae insecticide) (28.9%) were the other control measures utilised. Community perspectives revealed that 5.0% of the respondents were aware of biocontrol as a control method for the mosquito population. The biological method was considered safe for public health while guppy was reported as the most effective biocontrol agent. The introduction of novel and successful community programmes is significantly influenced by the perception of control measures for mosquitoes.

COMMUNITY PERSPECTIVE ON PREVENTION AND CONTROL STRATEGIES OF DENGUE INFECTION IN MALAYSIA

Dengue is a vector-borne disease caused by a rapidly-spreading virus. Dengue vector control is considered the most efficient way for limiting and curbing the spread of the dengue virus. This study aimed to determine the perception of the Malaysian community towards control measures of mosquitoes and the utilisation of biocontrol. A total of 402 respondents in Putrajaya and Selangor participated in the survey. The questionnaire was broadly divided into three sections: Knowledge of biological control, respondent profiles, knowledge of dengue fever prevention, and the utilisation of insecticide for mosquito control. Most of the respondents (83.0%) expressed concern regarding the effects of fogging activities on their health, whereas slightly more than half (56.0%) posited that fogging activities may have adverse environmental effects. The fogging method was reported as the most frequent method (29.2%) employed in controlling the mosquito population. Biocontrol with guppy fish scored (15.5%) and ABATE (mosquito larvae insecticide) (28.9%) were the other control measures utilised. Community perspectives revealed that 5.0% of the respondents were aware of biocontrol as a control method for the mosquito population. The biological method was considered safe for public health while guppy was reported as the most effective biocontrol agent. The introduction of novel and successful community programmes is significantly influenced by the perception of control measures for mosquitoes.

Analysis of Risk Factors for Dengue Hemorrhagic Fever in Riau Province using Negative Binomial Regression

Dengue Hemorrhagic Fever (DHF) is a serious threat in Riau province, Indonesia. To better understand and control the spread of dengue fever, this research aims to analyze the factors that cause dengue fever. This study aims to identify significant risk factors that influence the spread of dengue fever in Riau Province. The Negative Binomial Regression Method was used to identify factors associated with the increase in dengue fever cases in Riau. The variables evaluated include population density of the Aedes aegypti vector , level of environmental cleanliness, prevention practices, and socio-economic factors. In addition, the best model was selected to overcome overdispersion in the data. The results of the analysis show that factors such as population density of the Aedes aegypti vector , environmental cleanliness, and the level of public understanding about dengue prevention practices have a significant influence on the spread of dengue fever in Riau. The best model used to overcome overdispersion in the 2021 dengue fever case data in Riau is Negative Binomial Regression. This research provides a deeper understanding of the factors causing dengue fever in Riau and selects an appropriate statistical model for analyzing data that experiences overdispersion. Negative Binomial Regression proved to be more appropriate in overcoming the problem of overdispersion in the data. These results can be used as a basis for designing more effective dengue prevention and control strategies and provide guidance for more targeted interventions in fighting dengue fever in this region.

School and community driven dengue vector control and monitoring in Myanmar: Study protocol for a cluster randomized controlled trial.

Dengue is the most common and widespread mosquito-borne arboviral disease globally estimated to cause >390 million infections and >20,000 deaths annually. There are no effective preventive drugs and the newly introduced vaccines are not yet available. Control of dengue transmission still relies primarily on mosquito vector control. Although most vector control methods currently used by national dengue control programs may temporarily reduce mosquito populations, there is little evidence that they affect transmission. There is an urgent need for innovative, participatory, effective, and locally adapted approaches for sustainable vector control and monitoring in which students can be particularly relevant contributors and to demonstrate a clear link between vector reduction and dengue transmission reduction, using tools that are inexpensive and easy to use by local communities in a sustainable manner. Here we describe a cluster randomized controlled trial to be conducted in 46 school catchment areas in two townships in Yangon, Myanmar. The outcome measures are dengue cases confirmed by rapid diagnostic test in the townships, dengue incidence in schools, entomological indices, knowledge, attitudes and practice, behavior, and engagement. The trial involves middle school students that positions them to become actors in dengue knowledge transfer to their communities and take a leadership role in the delivery of vector control interventions and monitoring methods. Following this rationale, we believe that students can become change agents of decentralized vector surveillance and sustainable disease control in line with recent new paradigms in integrated and participatory vector surveillance and control. This provides an opportunity to operationalize transdisciplinary research towards sustainable health development. Due to the COVID-19 pandemic and political instability in Myanmar the project has been terminated by the donor, but the protocol will be helpful for potential future implementation of the project in Myanmar and/or elsewhere.Registration: This trial was registered in the ISRCTN Registry on 31 May 2022 ( https://doi.org/10.1186/ISRCTN78254298).

Larvicidal effect of Spinosad and Bacillus thuringiensis var. israelensis on Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

The use of biological larvicide based on Bacillus thuringiensis var. israelensis (Bti) has stood out for its effectiveness in controlling mosquito Aedes aegypti. The larvicide Spinosad is used in the National Dengue Control Program. This study evaluated the effect of Spinosad and Bti larvicide at various temperatures in a laboratory environment. The assays were performed with 10 larvae in quintuplicate, at temperatures of 18° C, 25° C and 32° C, with 24-hour monitoring. The larvae exposed to Bti were eliminated within 0.5 hours at ambient and hot temperatures (32° C), while at colder conditions (18° C) it took 1.5 hours for complete elimination. Regarding Spinosad, 50% survived for 11 hours, but all larvae were killed after 24 hours. The results reinforce the indication of these products for larval control of the species under the conditions of temperature fluctuation.

Stegomyia indices and pattern recognition of Aedes aegypti (Diptera: Culicidae) in selected agrogeoclimatic zones of Punjab, Pakistan

Mosquito-borne diseases especially, dengue is gaining currency nowadays in Pakistan. As there is no approved dengue vaccine available worldwide, prevention and control of vector is the only solution amid prevailing circumstances. The present study is a maiden attempt to screen indoor and outdoor breeding containers for the presence of Aedes (Ae.) aegypti larvae from selected study districts of Punjab, Pakistan i.e., Dera Ghazi Khan (DG Khan), Chakwal, and Faisalabad. A total of 384 houses from each study districts were surveyed for a calendar year. Mosquito larvae were collected, preserved, and identified using standard taxonomic keys. House Index (HI), Container Index (CI), and Breteau Index (BI) were estimated. Chi-square analysis was applied to calculate the association between Ae. aegypti larvae and breeding containers. Chakwal was identified with the highest values of Stegomyia indices (HI = 46.61 %, BI = 91.67 %, and CI = 15.28 %) followed by Faisalabad (HI = 34.11 %, BI = 68.75 % and, CI = 13.04 %) and DG Khan (HI = 28.39 %, BI = 68.23 % and, CI = 11.29 %). Earthen jars, tree holes, and water tanks were found significantly (p < 0.05) associated with the abundance of larvae irrespective of the geographical location. However, flower tubs and plastic buckets were found significantly (p < 0.05) associated in Faisalabad and Chakwal while, tyres and plastic bottles were found associated (p < 0.05) with the abundance of Ae. aegypti larvae in Faisalabad and DG Khan. These findings will help the stakeholders to devise appropriate preventive measures in combating the risk of dengue transmission.

Strengthening dengue control in Pakistan.

Strengthening dengue control in Pakistan.

Effects of the Covid-19 pandemic on the actions of the dengue control program in a metropolitan area in the southeast region of Brazil

The COVID-19 pandemic represents a challenge for health systems, straining available material and personal resources, interfering with other surveillance and control programs. Dengue is epidemiologically the most relevant urban arbovirus of Latin America, being endemic in the metropolitan municipality of Contagem in Minas Gerais State, southeast region of Brazil. This is an ecological study that aimed to analyze the effects of the COVID-19 epidemic on dengue control and surveillance in Contagem in the year of 2020. In 2020, the municipality presented more dengue cases than expected for non-epidemic years, with a sharp decline from epidemiological week 11 onwards, coinciding with the increase in COVID-19 cases. There was also a reduction in vector control, with the national suspension of the second Survey of Rapid Infestation Index of Aedes aegypti and a significant decrease in the installation of oviposition traps, properties visited for monitoring and that received focal treatment. Our results and the difficulties observed in different instances of dengue control corroborate the hypothesis of weakening of the surveillance program and possible underreporting of dengue cases as a result of the COVID-19 emergency. KEY WORDS: COVID-19; dengue; epidemiology; syndemic; public health surveillance.

BETWEEN INNOVATION AND UNCERTAINTY: A COMPREHENSIVE ANALYSIS OF THE RISKS ASSOCIATED WITH OX513A AND OX5034 GENETICALLY MODIFIED MOSQUITOES IN ARBOVIRUS CONTROL

The risks associated with genetically modified mosquitoes (GMOs) in combating arboviruses, specifically the strains of Aedes aegypti developed by Oxitec, have raised growing concerns due to potential dangers. With dengue becoming endemic in over 100 countries, the search for alternatives in vector control includes the use of GMOs. However, the introduction of these mosquitoes raises considerable concerns regarding potential risks to ecosystems and human health. Employing PRISMA guidelines, a database search identified 913 studies, of which only 4 were included after careful selection. The results highlight relevant findings, such as genomic instability in strains like OX513A and performance disparities between genetically modified mosquitoes and their wild counterparts. The review emphasizes the critical importance of dengue control in Brazil, considering factors like virus genetic variability and challenges in implementing control strategies, including the use of GMOs. Regulation of these organisms is conducted by CTNBio; however, the lack of consensus among various agencies raises doubts about the benefits of implementing these organisms. Given this landscape, the review underscores the ongoing need for monitoring the risks associated with genetically modified mosquitoes, encompassing not only biological implications but also environmental consequences. This approach is imperative for a comprehensive and informed assessment of the efficacy and safety of these organisms in the context of arbovirus control.

Societal knowledge, attitude, and practices towards dengue and associated factors in epidemic-hit areas: Geoinformation assisted empirical evidence

Dengue is one of Pakistan's major health concerns. In this study, we aimed to advance our understanding of the levels of knowledge, attitudes, and practices (KAPs) in Pakistan's Dengue Fever (DF) hotspots. Initially, at-risk communities were systematically identified via a well-known spatial modeling technique, named, Kernel Density Estimation, which was later targeted for a household-based cross-sectional survey of KAPs. To collect data on sociodemographic and KAPs, random sampling was utilized (n = 385, 5 % margin of error). Later, the association of different demographics (characteristics), knowledge, and attitude factors—potentially related to poor preventive practices was assessed using bivariate (individual) and multivariable (model) logistic regression analyses. Most respondents (>90 %) identified fever as a sign of DF; headache (73.8 %), joint pain (64.4 %), muscular pain (50.9 %), pain behind the eyes (41.8 %), bleeding (34.3 %), and skin rash (36.1 %) were identified relatively less. Regression results showed significant associations of poor knowledge/attitude with poor preventive practices; dengue vector (odds ratio [OR] = 3.733, 95 % confidence interval [CI ] = 2.377–5.861; P < 0.001), DF symptoms (OR = 3.088, 95 % CI = 1.949–4.894; P < 0.001), dengue transmission (OR = 1.933, 95 % CI = 1.265–2.956; P = 0.002), and attitude (OR = 3.813, 95 % CI = 1.548–9.395; P = 0.004). Moreover, education level was stronger in bivariate analysis and the strongest independent factor of poor preventive practices in multivariable analysis (illiterate: adjusted OR = 6.833, 95 % CI = 2.979–15.672; P < 0.001) and primary education (adjusted OR = 4.046, 95 % CI = 1.997–8.199; P < 0.001). This situation highlights knowledge gaps within urban communities, particularly in understanding dengue transmission and signs/symptoms. The level of education in urban communities also plays a substantial role in dengue control, as observed in this study, where poor preventive practices were more prevalent among illiterate and less educated respondents.

Dengue a global threat: An insight into management and control

Abstract Background : Dengue, whose severe forms have the potential to be fatal, is the most prevalent and rapidly proliferating vector-borne viral disease worldwide. It is evolving as a significant public health and economic dilemma for both rural and urban communities. Objectives : Given the urgent need for control measures, the purpose of this study is to evaluate both traditional and contemporary preventive strategies. Results : Traditional dengue control measures, while somewhat effective, tend to provide only temporary relief. In contrast, biotechnological innovations such as paratransgenesis, sterile insect technology, and genetically modified vectors have increased the effectiveness of conventional methods. In addition, the novel discovery of vaccines and immunotherapies offers a promising avenue for the management of dengue. Discussion &amp; Conclusion: Integration of time-tested techniques with the most recent biotechnological interventions emerges as a crucial dengue-prevention strategy. While these developments offer cause for optimism, additional research is required to determine the long-term implications and viability of these techniques. Implications : The findings have significant implications for theory, policymaking, and medical practice, highlighting the need for a combined approach to dengue management.

Acceptability of a hypothetical dengue vaccine and the potential impact of dengue vaccination on personal vector control behavior: a qualitative study in Fortaleza, Brazil

BackgroundDengue is the most rapidly spreading viral vector-borne disease in the world. Promising new dengue vaccines have contributed to a growing consensus that effective dengue control will require integrated strategies of vaccination and vector control. In this qualitative study, we explored the perspectives of residents of Fortaleza, Brazil on acceptability of a hypothetical safe and effective dengue vaccine, specific drivers of dengue vaccine acceptance or hesitance, and the expected impact of dengue vaccination on their personal vector control practices.MethodsA total of 43 in-depth interviews were conducted from April to June 2022 with Fortaleza residents from a diverse range of educational and professional backgrounds, with and without recent personal experiences of symptomatic dengue infections. Data were analyzed using the principles of inductive grounded theory methodology.ResultsOur findings indicate that knowledge of dengue transmission, symptoms, and prevention methods was strong across respondents. Respondents described willingness to accept a hypothetical dengue vaccine for themselves and their children, while emphasizing that the vaccine must be demonstrably safe and effective. Respondents expressed diverse perspectives on how receiving a safe and effective dengue vaccine might influence their personal vector control behaviors, relating these behaviors to their perception of risk from other Aedes mosquito-carried infections and beliefs about the role of vector control in maintaining household cleanliness.ConclusionsOur study findings provide community-level perspectives on dengue vaccination and its potential impact on personal vector control behavior for policymakers and program managers in Fortaleza to consider as new dengue vaccines become available. With the introduction of any new dengue vaccine, community perspectives and emerging concerns that may drive vaccine hesitancy should be continuously sought out. Improved urban infrastructure and efforts to engage individuals and communities in vector control may be needed to optimize the impact of future dengue vaccinations and prevent rising cases of other arboviruses such as Zika and chikungunya.

Dengue Infection Survey on Prevention and Control Strategies Among Community in Malaysia

Dengue is a vector-borne disease caused by a rapidly spreading virus. Dengue vector control is considered the most efficient way for limiting and curbing the spread of the dengue virus. This study aimed to determine the perception of the Malaysian community towards prevention and control measures of Dengue infection. A total of 402 respondents in Putrajaya and Selangor participated in the survey. The questionnaire was broadly divided into three sections: i) respondent profile ii) knowledge about prevention of Dengue Fever and insecticide use for mosquito control iii) knowledge about biological control.Most of the respondents (83.0%) expressed concern regarding the effects of fogging activities on their health, whereas slightly more than half (56.0%) posited that fogging activities may have adverse environmental effects. The fogging method was reported as the most frequent method (29.2%) employed in controlling the mosquito population. Biocontrol with guppy fish scored (15.5%) and Abate® (mosquito larvae insecticide) (28.9%) were the other control measures utilised. Community perspectives revealed that 5.0% of the respondents were aware of biocontrol as a control method for the mosquito population. The biological method was considered safe for public health while guppy was reported as the most effective biocontrol agent. The introduction of novel biocontrol and successful community programmes is significantly influenced by the perception of prevention and control measures for mosquitoes.

Phylogenetic analysis of Aedes species distributed in Taif Province, Saudi Arabia, based on mitochondrial COX1 sequences

AbstractAs Aedes mosquitoes are the predominant carriers of arboviruses responsible for global dengue fever and chikungunya outbreaks, understanding their genetic diversity and population structure can enhance dengue prevention and vector control efforts. Although sympatric cryptic species have been acknowledged in Aedes species subgroups in Southeast Asia, little information is available regarding the occurrence and dispersal of cryptic Aedes species in Saudi Arabia. In the present investigation, we intend to analyze genetic variations and perform a phylogenetic study of sympatric Aedes samples collected from various locations in Taif Province, Saudi Arabia. The locus of mitochondrial DNA cytochrome c oxidase subunit 1 (COX1, analyzed with DNA barcoding) was utilized to determine genetic variance and to build phylogenetic trees. For species identification, the COX1 sequences of Aedes samples from Taif Province were compared with those of Aedes samples from GenBank (National Center for Biotechnology Information, NCBI). To identify phylogenetic relationships and genetic variability, phylogenetic trees were created using Taif Province samples, GenBank A. albopictus samples, and GenBank A. aegypti samples. The phylogenetic analysis revealed that some Taif samples (A3, A7, F2, F4, F1, A4, A1, F9 and F6) were closer to A. aegypti and A. albopictus samples from Africa and East Asia, especially Kenya and Malaysia. Whereas other samples (F9, F6, A4, F1 and A1) were closer to the GenBank A. aegypti samples KP843383 (Thailand), HM399357(Australia), MK533632 (Kenya), KX420460 (Kenya), KU495081 (Australia) and MF179160 (China) than the remaining Taif samples. Overall, our findings demonstrate that examining the genetic diversity and phylogenetic linkages of Aedes samples can aid in understanding the evolution of Aedes cryptic species in the western regions of Saudi Arabia.

Correlation between pyrethroid knockdown resistance and mutation frequency of voltage-gated sodium channel and its application in Aedes aegypti management

Aedes aegypti, the primary vector responsible for transmitting dengue fever in southern Taiwan, has developed a relatively high resistance to synthetic pyrethroids. It has evolved four amino acid substitutions in the voltage-gated sodium channel (VGSC), namely S996P, V1023G, F1565C, and D1794Y. To unveil the distribution and correlation of VGSC mutations and pyrethroid resistance among different field populations, Ae. aegypti collected from various districts in Kaohsiung and Tainan Cities underwent tests for resistance development against different pyrethroids and frequency of S996P, V1023G, F1565C, and D1794Y substitutions. The adult knockdown assay revealed a relatively high knockdown resistance in the Ae. aegypti populations from Kaohsiung and Tainan against permethrin, cypermethrin, and fenvalerate (averaging >50-fold). Conversely, less resistance was observed against α-cypermethrin, deltamethrin, λ-cyhalothrin, cyfluthrin, and etofenprox (averaging <35-fold). Using Polymerase Chain Reaction/restriction fragment length polymorphism analysis, four mutant haplotypes were identified in these field populations. Notably, the SIAVFD and SIBVFD wild haplotypes were absent. Analysis utilizing IBM SPSS Statistics 20.0 and Spearman's rank correlation coefficient indicated that Haplotype C (PIAGFD), especially P allele, frequency displayed a significant positive correlation with five Type II pyrethroid resistance, while 1023G and 1023G/G exhibited a significant association with permethrin and fevalerate resistance. Conversely, Haplotype E (SIBVCD) negatively correlated with pyrethroid resistance, particularly fenvalerate resistance (−0.776). Haplotype C and E were the most prevalent and widely distributed among the investigated field populations. This prevalence of haplotype C is likely tied to the extensive and excessive use of Type II pyrethroids for dengue control over the past three decades. Given the significant positive correlation, the best-fit lines and R2 values were established to facilitate the swift prediction of knockdown resistance levels to various pyrethroids based on VGSC mutation frequency. This predictive approach aims to guide insecticide usage and the management of pyrethroid resistance in the field populations of Ae. aegypti in Taiwan.

The need for multisectoral actions for dengue control in Peru: A One Health approach

Sr. Editor, La infección por el virus del dengue se ha convertido en la primera emergencia sanitaria en varios países de América Latina, especialmente en Perú, donde al primer semestre del 2023 hubo más 206 mil casos y 357 muertes. Pero, ¿cuál es la mejor perspectiva para analizar el problema del dengue en el Perú?

Utility of surveillance data for planning for dengue elimination in Yogyakarta, Indonesia: a scenario-tree modelling approach

IntroductionField trials and modelling studies suggest that elimination of dengue transmission may be possible through widespread release of Aedes aegypti mosquitoes infected with the insect bacterium Wolbachia pipientis (wMel strain),...

Spatio-Temporal Determinants of Dengue Epidemics in the Central Region of Burkina Faso.

The aim of this study was to analyze the spatio-temporal distribution and determinants of the 2017 dengue epidemic in Burkina Faso. A principal component analysis of meteorological and environmental factors was performed to reduce dimensions and avoid collinearities. An initial generalized additive model assessed the impact of the components derived from this analysis on dengue incidence. Dengue incidence increased mainly with relative humidity, precipitation, normalized difference vegetation index and minimum temperature with an 8-week lag. A Kulldoff Satscan scan was used to identify high-risk dengue clusters, and a second generalized additive model assessed the risk of a health area being at high risk according to land-use factors. The spatio-temporal distribution of dengue fever was heterogeneous and strongly correlated with meteorological factors. The rural communes of Sabaa and Koubri were the areas most at risk. This study provides useful information for planning targeted dengue control strategies in Burkina Faso.