Spread Of Vector-borne Diseases Research Articles

Insights from multigene analysis: first report of a Southeast Asian Mosquito, Aedes (Mucidus) laniger (Diptera: Culicidae) on Jeju Island from Korea

BackgroundCertain mosquitoes are known as dominant vectors worldwide, and transmit infectious diseases. The expansion of mosquito habitats due to climate change and increased human activities poses a significant health threat by facilitating the spread of various non-native infectious diseases. This study focused on the detection of the Southeast Asian mosquito species, Aedes (Mucidus) laniger (Wiedemann, 1820) on Jeju Island, the southernmost region of the Republic of Korea (ROK), highlighting the potential risks associated with the spread of vector-borne diseases, particularly emphasizing the elevated likelihood of invasion by Southeast Asian mosquitoes.MethodsField surveys were conducted in August 2023 on Jeju Island. Adult mosquitoes were collected using BG-sentinel traps and identified to the species level using taxonomic keys. Morphological and molecular analyses were employed to confirm species designations. Molecular data, including mitochondrial and nuclear genes, were used for phylogenetic analysis, which was performed to compare and identify among recorded subgenera in ROK. Species distribution modeling for Ae. laniger was performed to predict potential habitats using R package ‘BIOMOD2’.ResultsThe two specimens of Ae. laniger were collected for the first time on Jeju Island. Morphological and molecular analyses confirmed the identity of this species within the subgenus Mucidus and validated the first record of this species in the ROK. We employed a simple multigene phylogenetic analysis to confirm a new mosquito record at the genus and subgenus levels, finally validating the consistency between morphological identification and molecular phylogenetic outcomes. Furthermore, we have updated the taxonomic keys for the genus Aedes in the ROK, and revised mosquito lists for Jeju Island, incorporating the inclusion of Ae. laniger. On the basis of species distribution modeling, the area of suitable habitat for Ae. laniger is expected to expand due to climate change, but this change did not appear to be meaningful in East Asia.ConclusionsThis case offers the first report of the Southeast Asian mosquito, Ae. laniger, in the ROK. The detection of this species on Jeju Island suggests the potential establishment of a breeding population their habitat and raises concerns about further expansion into the Korean Peninsula. Considering the annual occurrence of mosquito-borne disease cases in the Southeast Asia, it is essential to conduct monitoring not only in Jeju Island, where Ae. laniger has been identified, but also across the entire Korean Peninsula.Graphical

Surveillance of sand flies (Psychodidae, Phlebotominae) from Mexico: Altitudinal and climatic patterns after historical and new geographic records in endemic areas of leishmaniasis

This study updates knowledge on historical geographic distribution of sand fly species through identifying altitudinal and bioclimatic patterns in leishmaniasis endemic areas in Mexico. We analyze and identify sand fly specimens obtained through national efforts by the Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, Mexico), collected between 1995 and 2001, 2008–2012, and 2017–2023, and add bibliographic information (427 additional records). After a principal components analysis of WorldClim variables and altitudinal ranges, variables that better explain the distribution of sand fly species were chosen (BIO6, BIO12, and BIO16, explaining 72 % of variation). A total of 1,187 specimens of 22 species were retrieved from eight states, providing 29 new municipalities and 48 new localities, being Lutzomyia cruciata, Micropygomyia chiapanensis, and Psathyromyia shannoni the most common species. We presented new historical records of distribution for sand fly species from Morelos (3), Oaxaca (7) and Tabasco (1). The 82.7 % of sand fly species analyzed were distributed in areas with altitudinal ranges below 420 m. The anthropophilic species Psathyromyia shannoni, and Lutzomyia cruciata showed the greatest variability regarding altitudinal range, and climatic preferences, while several wild species showed abiotic preferences. It is likely that the effect of urbanization and climate change generate new beneficial biotopes for the proliferation of the vector sand fly species. Complementary studies that consider seasonality, vegetation types, and change in land use could provide new information to better understand the spread of vector-borne diseases.

Assessing Environmental Risks during the Drug Development Process for Parasitic Vector-Borne Diseases: A Critical Reflection.

Parasitic vector-borne diseases (VBDs) represent nearly 20% of the global burden of infectious diseases. Moreover, the spread of VBDs is enhanced by global travel, urbanization, and climate change. Treatment of VBDs faces challenges due to limitations of existing drugs, as the potential for side effects in nontarget species raises significant environmental concerns. Consequently, considering environmental risks early in drug development processes is critically important. Here, we examine the environmental risk assessment process for veterinary medicinal products in the European Union and identify major gaps in the ecotoxicity data of these drugs. By highlighting the scarcity of ecotoxicological data for commonly used antiparasitic drugs, we stress the urgent need for considering the One Health concept. We advocate for employing predictive tools and nonanimal methodologies such as New Approach Methodologies at early stages of antiparasitic drug research and development. Furthermore, adopting progressive approaches to mitigate ecological risks requires the integration of nonstandard tests that account for real-world complexities and use environmentally relevant exposure scenarios. Such a strategy is vital for a sustainable drug development process as it adheres to the principles of One Health, ultimately contributing to a healthier and more sustainable world.

Central nervous system infections in the tropics.

Emerging and re-emerging central nervous system (CNS) infections are a major public health concern in the tropics. The reasons for this are myriad; climate change, rainfall, deforestation, increased vector density combined with poverty, poor sanitation and hygiene. This review focuses on pathogens, which have emerged and re-emerged, with the potential for significant morbidity and mortality. In recent years, multiple acute encephalitis outbreaks have been caused by Nipah virus, which carries a high case fatality. Arboviral infections, predominantly dengue, chikungunya and Zika are re-emerging increasingly especially in urban areas due to changing human habitats, vector behaviour and viral evolution. Scrub typhus, another vector borne disease caused by the bacterium Orientia tsutsugamushi , is being established as a leading cause of CNS infections in the tropics. A syndromic and epidemiological approach to CNS infections in the tropics is essential to plan appropriate diagnostic tests and management. Rapid diagnostic tests facilitate early diagnosis and thus help prompt initiation and focusing of therapy to prevent adverse outcomes. Vector control, cautious urbanization and deforestation, and reducing disturbance of ecosystems can help prevent spread of vector-borne diseases. Regional diagnostic and treatment approaches and specific vaccines are required to avert morbidity and mortality.

Temperature affects viral kinetics and vectorial capacity of Aedes aegypti mosquitoes co-infected with Mayaro and Dengue viruses

BackgroundIncreasing global temperatures and unpredictable climatic extremes have contributed to the spread of vector-borne diseases. The mosquito Aedes aegypti is the main vector of multiple arboviruses that negatively impact human health, mostly in low socioeconomic areas of the world. Co-circulation and co-infection of these viruses in humans have been increasingly reported; however, how vectors contribute to this alarming trend remains unclear.MethodsHere, we examine single and co-infection of Mayaro virus (D strain, Alphavirus) and dengue virus (serotype 2, Flavivirus) in Ae. aegypti adults and cell lines at two constant temperatures, moderate (27 °C) and hot (32 °C), to quantify vector competence and the effect of temperature on infection, dissemination and transmission, including on the degree of interaction between the two viruses.ResultsBoth viruses were primarily affected by temperature but there was a partial interaction with co-infection. Dengue virus quickly replicates in adult mosquitoes with a tendency for higher titers in co-infected mosquitoes at both temperatures, and mosquito mortality was more severe at higher temperatures in all conditions. For dengue, and to a lesser extent Mayaro, vector competence and vectorial capacity were higher at hotter temperature in co- vs. single infections and was more evident at earlier time points (7 vs. 14 days post infection) for Mayaro. The temperature-dependent phenotype was confirmed in vitro by faster cellular infection and initial replication at higher temperatures for dengue but not for Mayaro virus.ConclusionsOur study suggests that contrasting kinetics of the two viruses could be related to their intrinsic thermal requirements, where alphaviruses thrive better at lower temperatures compared to flaviviruses. However, more studies are necessary to clarify the role of co-infection at different temperature regimes, including under more natural temperature settings.Graphical

Climate Change and Women Health Vulnerabilities: Towards Mitigation and Response

Climate change affects all genders in myriad ways and causes catastrophic health hazards. While no one is safe from this unfolding risks, women are already disadvantaged and become most affected by climate change. Poor air quality, contaminated water, food insecurity, spread of vector borne diseases, disruption of sanitation and rising temperature etc. have overwhelming negative health impacts on women, especially on the reproductive health. Furthermore, climate policies in India lack gender sensitivity because of low awareness making women health more vulnerable. With this backdrop, the current paper has identified key areas of vulnerability among females due to their biology and the existing socio-cultural factors. In addition to the existing issues women are less likely to have accessibility of the resources to enjoy their fundamental health rights. There fore the current paper discuses better strategies for mitigation and response to climate change with the active participation of women, families and the whole community. After looking at various findings the paper concludes the need of the gender sensitive approach in the process of mitigation and response.

Vector-borne disease models with Lagrangian approach.

We develop a multi-group and multi-patch model to study the effects of population dispersal on the spatial spread of vector-borne diseases across a heterogeneous environment. The movement of host and/or vector is described by Lagrangian approach in which the origin or identity of each individual stays unchanged regardless of movement. The basic reproduction number [Formula: see text] of the model is defined and the strong connectivity of the host-vector network is succinctly characterized by the residence times matrices of hosts and vectors. Furthermore, the definition and criterion of the strong connectivity of general infectious disease networks are given and applied to establish the global stability of the disease-free equilibrium. The global dynamics of the model system are shown to be entirely determined by its basic reproduction number. We then obtain several biologically meaningful upper and lower bounds on the basic reproduction number which are independent or dependent of the residence times matrices. In particular, the heterogeneous mixing of hosts and vectors in a homogeneous environment always increases the basic reproduction number. There is a substantial difference on the upper bound of [Formula: see text] between Lagrangian and Eulerian modeling approaches. When only host movement between two patches is concerned, the subdivision of hosts (more host groups) can lead to a larger basic reproduction number. In addition, we numerically investigate the dependence of the basic reproduction number and the total number of infected hosts on the residence times matrix of hosts, and compare the impact of different vector control strategies on disease transmission.

MATHEMATICAL MODELING OF THE SPREAD OF VECTOR BORNE DISEASES WITH INFLUENCE OF VERTICAL TRANSMISSION AND PREVENTIVE STRATEGIES

This work is aimed at formulating a mathematical model of the spread of vector-borne diseases with influence of vertical transmission and preventive strategies. Vector borne diseases are caused by viruses, bacteria, and parasites typically conveyed by mosquitoes. Certain illnesses transmitted by vectors include West Nile Virus, Malaria, Zika virus, Dengue fever, Rift valley fever, and Viral encephalitis induced by pathogens like bacteria, viruses, and parasites. The positive solutions of the model are presented and the theory of basic reproduction number was used to study the model dynamical behaviour. When reduces; the diseases are wiped out of the population with time and vice versa. The disease free and endemic equilibria states of the model were determined and investigated to be locally and globally stable.We incorporated the use of Insecticide –Treated Nets (ITN), Indoor Residual Sprayings (IRS) and condom usage as preventive measures in the presence of treatment. Numerical simulations show that complete intervention measures, that is, the use of ITN, IRS and condom usage while placing the infected on treatment have valuable impact on the spread of vector-borne diseases.

Human dirofilariasis: a rare disease or a problem of our time?

The article presents the current state of the problem of dirofilariasis. Helminth infection caused by nematodes of the genus Dirofilaria is mainly a disease of carnivores from the canine and feline families. Humans are considered occasional hosts in which Dirofilaria spp., more commonly D. repens, rarely reach sexual maturity. The climatic conditions of the territory are one of the determining factors for the spread of vector-borne diseases. Due to the fact that in recent years there has been a tendency to increase average temperatures everywhere, these changes lead to a shift and expansion of the ranges of many organisms, including pathogens and vectors of various diseases. The clinical picture of human dirofilariasis caused by D. repens most often manifests itself in one of two clinical forms -subcutaneous and ocular, although, according to the literature, there are cases of damage to other localizations. Due to the fact that damage to the organs of vision occurs most often in humans, the clinical case presented by us is relevant. The patient, in our clinical case, permanently lived in one of the districts of the Ryazan region. The landscape and natural complex of this region, taking into account the presence of a large number of wetlands, an abundance of water bodies and suitable climatic conditions, creates a favorable environment for the development of insects of the Culicidae family (mosquitoes of the genera Anopheles, Culex, etc.), which are transmissible carriers of various human and animal diseases, including dirofilariasis. The complex cycle of the parasite, the possibility of migration in the body can lead to multiple organ damage. Scientific publications describe cases of finding dirofilaria in the lungs, heart, and genitourinary system. In this regard, the awareness of doctors and patients about this disease is very relevant, and will reduce the likelihood of prolonging the correct diagnosis and treatment.

Larvicidal activity of the photosensitive insecticides, methylene blue and rose bengal, in Aedes aegypti and Anopheles gambiae mosquitoes.

Insecticides are critical for controlling mosquito populations and mitigating the spread of vector-borne disease, but their overuse has selected for resistant populations. A promising alternative to classical chemical insecticides is photosensitive molecules - here called photosensitive insecticides or PSIs - that when ingested and activated by light, generate broadly toxic reactive oxygen species. This mechanism of indiscriminate oxidative damage decreases the likelihood that target site modification-based resistance evolves. Here, we tested whether the PSIs, methylene blue (MB) and rose bengal (RB), are viable insecticides across the mosquito lineage. MB and RB are phototoxic to both Aedes aegypti and Anopheles gambiae at micromolar concentrations, with greatest toxicity when larvae are incubated in the dark with the PSIs for 2 h prior to photoactivation. MB is ten times more toxic than RB, and microscopy-based imaging suggests that this is because ingested MB escapes the larval gut and disperses throughout the hemocoel whereas RB remains confined to the gut. Adding food to the PSI-containing water has a bidirectional, concentration-dependent effect on PSI toxicity; toxicity increases at high concentrations but decreases at low concentrations. Finally, adding sand to the water increases the phototoxicity of RB to Ae. aegypti. MB and RB are larvicidal via a light activated mechanism, and therefore, should be further investigated as an option for mosquito control. © 2023 Society of Chemical Industry.

The Influence of Environmental Issues on Health Promotion: A Historical Journey and Contemporary Challenges

In this editorial, we address the relationship between environmental issues and health promotion, highlighting how these topics are of great global relevance. Over the past decades, understanding of the complex links between health and the environment has progressed, with solid evidence on the adverse effects of air pollution, water contamination, inadequate waste management, biodiversity loss and climate change on human health. These environmental problems can cause a variety of diseases, including respiratory, cardiovascular, cancer and neurological disorders. Despite scientific advances in the field, challenges are persistent. Air pollution and ecosystem degradation continue to affect people's quality of life, compromising the availability of essential resources such as drinking water and food. Climate change also becomes a growing threat, leading to extreme weather events and the spread of vector-borne diseases. As such, integrated and sustainable approaches that protect both human health and the environment are needed. This requires coordinated action at local, national, and global levels, involving governments, the private sector, civil society, and individuals. It reinforces the need to strengthen environmental health surveillance systems, universalize access to basic sanitation and promote environmental education to raise awareness about the importance of health and the environment. We trace the historical evolution of the relationship between health and the environment, highlighting the influence of ancient thinkers such as Hippocrates, passing through moments of greater and lesser attention to environmental issues in public health. Events such as the Stockholm Conference in 1972, Eco-92 in 1992 and the adoption of the Sustainable Development Goals in 2015 are significant milestones in the promotion of environmental and health policies. Human health and the health of the planet are intrinsically linked, hence the need to rethink the development model and adopt effective measures to achieve global environmental goals, aiming to build a healthier, sustainable, and resilient world for present and future generations.

Genomic signatures of local adaptation in recent invasive Aedes aegypti populations in California

BackgroundRapid adaptation to new environments can facilitate species invasions and range expansions. Understanding the mechanisms of adaptation used by invasive disease vectors in new regions has key implications for mitigating the prevalence and spread of vector-borne disease, although they remain relatively unexplored.ResultsHere, we integrate whole-genome sequencing data from 96 Aedes aegypti mosquitoes collected from various sites in southern and central California with 25 annual topo-climate variables to investigate genome-wide signals of local adaptation among populations. Patterns of population structure, as inferred using principal components and admixture analysis, were consistent with three genetic clusters. Using various landscape genomics approaches, which all remove the confounding effects of shared ancestry on correlations between genetic and environmental variation, we identified 112 genes showing strong signals of local environmental adaptation associated with one or more topo-climate factors. Some of them have known effects in climate adaptation, such as heat-shock proteins, which shows selective sweep and recent positive selection acting on these genomic regions.ConclusionsOur results provide a genome wide perspective on the distribution of adaptive loci and lay the foundation for future work to understand how environmental adaptation in Ae. aegypti impacts the arboviral disease landscape and how such adaptation could help or hinder efforts at population control.

Modeling preferential attraction to infected hosts in vector-borne diseases.

Vector-borne infectious diseases cause more than 700,000 deaths a year and represent an increasing threat to public health worldwide. Strategies to mitigate the spread of vector-borne diseases can benefit from a thorough understanding of all mechanisms that contribute to viral propagation in human. A recent study showed that Aedes mosquitoes (the vectors for dengue and Zika virus, among others) are preferentially attracted to infected hosts. In order to determine the impact of this factor on viral spread, we built a dedicated agent-based model and parameterized it on dengue fever. We then performed a systematic study of how mosquitoes' preferential attraction for infected hosts affects viral load and persistence of the infection. Our results indicate that even small values of preferential attraction have a dramatic effect on the number of infected individuals and the persistence of the infection in the population. Taken together, our results suggests that interventions aimed at decreasing the preferential attraction of vectors for infected hosts can reduce viral transmission and thus can have public health implications.

The Implementation of the International Health Regulations on Vector-Borne Diseases: A Scoping Review of the Qualitative Evidence Performed Worldwide

Introduction: The International Health Regulations were created by the World Health Organization with the purpose of preventing the international spread of diseases. The 196 signatory countries are bound by this international agreement. In this article, we conducted a scoping review of the literature concerning the implementation and operationalization of measures at both the continental and national levels to prevent the spread of vector-borne diseases. The purpose was to understand the main strategies and policies adopted, as well as how they have been operating. Methods: Out of an initial search on PubMed™, SCOPUS™, and Web of Science™ using combinations of “International Health Regulations” and “vector-borne diseases”, 75 references were obtained, of which 27 were included after careful qualitative analysis. Results: Publication dates of included articles ranged from 1996 to 2022. Four major categories of measures were identified: (a) surveillance and epidemic intelligence; (b) Declaration of Public Health Emergency of International Concern; (c) measures in Points of Entry; and (d) vaccination status. Implemented measures were found in all continents: Africa, Oceania (Australia), Asia (China, India, Taiwan), Europe (Ireland, the Netherlands, and Mediterranean countries), North America (USA), and South America (Brazil). Yellow fever, Zika, Dengue, and Chikungunya were the most cited vector-borne diseases but Crimean-Congo hemorrhagic fever, Japanese encephalitis, Lyme disease, Malaria, Leishmaniasis, Tick-borne encephalitis, and West Nile fever were also mentioned. Conclusion: There are severe asymmetries across countries on the implementation of international regulations with regards to vector-borne diseases, particularly on the issue of surveillance systems. State Parties should consider the lessons learned from the pandemic and perfect their core capacities to prevent future outbreaks of infectious diseases.

Using machine learning to understand microgeographic determinants of the Zika vector, Aedes aegypti.

There are limited data on why the 2016 Zika outbreak in Miami-Dade County, Florida was confined to certain neighborhoods. In this research, Aedes aegypti, the primary vector of Zika virus, are studied to examine neighborhood-level differences in their population dynamics and underlying processes. Weekly mosquito data were acquired from the Miami-Dade County Mosquito Control Division from 2016 to 2020 from 172 traps deployed around Miami-Dade County. Using random forest, a machine learning method, predictive models of spatiotemporal dynamics of Ae. aegypti in response to meteorological conditions and neighborhood-specific socio-demographic and physical characteristics, such as land-use and land-cover type and income level, were created. The study area was divided into two groups: areas affected by local transmission of Zika during the 2016 outbreak and unaffected areas. Ae. aegypti populations in areas affected by Zika were more strongly influenced by 14- and 21-day lagged weather conditions. In the unaffected areas, mosquito populations were more strongly influenced by land-use and day-of-collection weather conditions. There are neighborhood-scale differences in Ae. aegypti population dynamics. These differences in turn influence vector-borne disease diffusion in a region. These results have implications for vector control experts to lead neighborhood-specific vector control strategies and for epidemiologists to guide vector-borne disease risk preparations, especially for containing the spread of vector-borne disease in response to ongoing climate change.

An Emerging Infectious Disease Surveillance Platform for the 21st Century

Current vector surveillance programs are insufficient for coping with the emerging infectious disease crisis. In particular, current practices do not deploy sufficient information technology (IT) tools to generate actionable insights that can inform interventions and contain and mitigate the spread of vector-borne diseases. VectorAnalytica has developed a highly configurable and adaptable IT platform that imports, harmonizes, and integrates a range of data sources. The state-of-the-art backend development allows users to fully appreciate and understand the complexity of infectious disease dynamics without having to resort to additional statistical and GIS software packages. The platform yields actionable insights into outbreak patterns of vector-borne diseases that could not have been obtained without integrating pertinent contextual information at a granular spatiotemporal scale. Such integration empowers local scientists to participate actively in an ongoing manner in protecting their communities. The platform can also empower regional and national scientists and other scholars and agencies by providing them with a shared platform through which they can access continuously updated real-time data with which to formulate, validate, and update new dynamic forecasting and simulating models that support timely and appropriate decision-making and interventions on a wide range of scales. VectorAnalytica’s effectiveness is described in three cases studies for which integrating and visualizing unexpected but pertinent variables (in addition to those traditionally studied for vector disease monitoring and management) yielded critical information about significant correlations between weather variables and disease incidence, and between complaints to local call centers, weather conditions, and emergent vector hotspots.

Knowledge, Attitudes and Perception of Mosquito Control in Different Citizenship Regimes within and Surrounding the Malakasa Open Accommodation Refugee Camp in Athens, Greece.

The study aims to evaluate the Knowledge, Attitude and Perception (KAP) of different societal groups concerning the implementation of targeted community-based mosquito surveillance and control interventions in different citizenship regimes. Targeted surveys were carried out within Malakasa camp for migrants and refugees, neighboring residential areas and urban areas in the wider Athens metropolitan area to investigate different knowledge levels and the role that both local and migrant communities can play in the implementation of community-based interventions based on their attitudes and perceptions. A scoring system was used to rate the collected responses. Results indicate different levels of KAP among the various groups of respondents and different priorities that should be considered in the design and execution of community interventions. Findings indicate a lower level of Knowledge Attitudes and Perceptions for the migrants, while the rate of correct answers for Perception significantly improved for migrants following a small-scale information session. The study highlights disparities in the levels of knowledge for certain public health issues and the feasibility of certain approaches for alleviating health-related challenges such as mosquito-borne diseases. Findings suggest that essential preparedness is needed by public authorities to respond to public health challenges related to migration and the spread of vector-borne diseases.

Climate Change Drives the Transmission and Spread of Vector-Borne Diseases: An Ecological Perspective.

Climate change affects ecosystems and human health in multiple dimensions. With the acceleration of climate change, climate-sensitive vector-borne diseases (VBDs) pose an increasing threat to public health. This paper summaries 10 publications on the impacts of climate change on ecosystems and human health; then it synthesizes the other existing literature to more broadly explain how climate change drives the transmission and spread of VBDs through an ecological perspective. We highlight the multi-dimensional nature of climate change, its interaction with other factors, and the impact of the COVID-19 pandemic on transmission and spread of VBDs, specifically including: (1) the generally nonlinear relationship of local climate (temperature, precipitation and wind) and VBD transmission, with temperature especially exhibiting an n-shape relation; (2) the time-lagged effect of regional climate phenomena (the El Niño-Southern Oscillation and North Atlantic Oscillation) on VBD transmission; (3) the u-shaped effect of extreme climate (heat waves, cold waves, floods, and droughts) on VBD spread; (4) how interactions between non-climatic (land use and human mobility) and climatic factors increase VBD transmission and spread; and (5) that the impact of the COVID-19 pandemic on climate change is debatable, and its impact on VBDs remains uncertain. By exploring the influence of climate change and non-climatic factors on VBD transmission and spread, this paper provides scientific understanding and guidance for their effective prevention and control.

Does public intervention in dealing with problems of mosquitoes/flies in India crowd out private initiatives?

ABSTRACT The spread of vector-borne diseases poses considerable public health challenges in India, such that both government and private households engage in initiatives to tackle the problem. This study utilises two nationally representative datasets (2018 and 2012) to determine if action undertaken by state/local government(s) in India in tackling the problems of mosquitoes/flies is associated with a crowding out of private efforts in addressing the problem; or instead is associated with greater private action. Study findings reveal that local/state government action is associated with an increase in household effort in dealing with the problem of mosquitoes/flies. Action by state/local governments in India may convey information to households which may alter their decision-making calculus regarding returns on investments triggering an increase in private effort complementing the public effort. Accordingly, simple government-sponsored advertising campaigns may not be efficacious in promulgating desired behavioural responses. This study finds that direct government action aimed at mitigating the transmission of vector-borne diseases, together with investment in education, social infrastructure and health system interaction may provide positive information signals to households thus enhancing private investment in health-related activity.

Solid waste recycling and management cost optimization algorithm

Solid waste is a major issue in today's world. Which can be a contributing factor to pollution and the spread of vector-borne diseases. Because of its complicated nonlinear processes, this problem is difficult to model and optimize using traditional methods. In this study, a mathematical model was developed to optimize the cost of solid waste recycling and management. In the optimization phase, the salp swarm algorithm (SSA) is utilized to determine the level of discarded solid waste and reclaimed solid waste. An optimization technique SSA is a new method of finding the ideal solution for a mathematical relationship based on leaders and followers. It takes a lot of random solutions, as well as their outward or inward fluctuations, to find the optimal solution. This method also included multiple adaptive and random variables to guarantee that the solution space was explored and used in various optimization tasks. When all criteria are considered, the results of this study show that the SSA is efficient for least-distance path allocation. The simulation findings reveal a significant improvement over the well-known particle swarm optimization (PSO) algorithm, with recycling and disposal costs decreasing by 10% to 30%.