Wide and increasing suitability for Aedes albopictus in Europe is congruent across distribution models

Ecological risk factors for the establishment of West Nile virus in Britain

West Nile virus (WNV) is a zoonotic mosquito-borne virus which is emerging across Europe, largely due to climate and other environmental changes. Detection of WNV at increasingly northern latitudes raises concern that WNV may be introduced to Britain, where ecological conditions could eventually support sustained transmission. Establishment of WNV depends on spatial and temporal overlap between infectious migratory birds and native vectors. However, understanding of the distributions and phenology of key vector species in Britain is incomplete and must be updated to prioritise activities for WNV surveillance and response. Here, we review recent findings related to WNV ecology in continental Europe and the ecology of British mosquito species in order to evaluate the risk of WNV establishment in Britain.

Excellent capability for molecular detection of Aedes-borne dengue, Zika, and chikungunya viruses but with a need for increased capacity for yellow fever and Japanese encephalitis viruses: an external quality assessment in 36 European laboratories

Mosquito-borne viruses represent a large global health burden. With geographic expansion of competent vectors for chikungunya virus (CHIKV), dengue virus (DENV), and Zika virus (ZIKV) in Europe, it is anticipated that the number of autochthonous cases of these tropical viruses in Europe will increase. Therefore, regular assessment of diagnostic capabilities in Europe is important. Our aim was to evaluate the mosquito-borne virus molecular detection capability of expert European laboratories by conducting an external quality assessment in October 2023. Molecular panels included 12 plasma samples: one alphavirus (CHIKV), four orthoflaviviruses (ZIKV, yellow fever virus [YFV], DENV, and Japanese encephalitis virus [JEV]), and two negative control samples. Mosquito-borne virus detection was assessed among 36 laboratories in 24 European countries. Adequate capabilities were lacking for YFV and JEV. Many laboratories relied on a mix of laboratory-developed tests (some of which were pan-orthoflavivirus or pan-alphavirus in combination with sequencing) and commercial assays. 47.2% of laboratories characterized all external quality assessment (EQA) samples correctly. Correct result rates were 100% for CHIKV and ZIKV and >99% for DENV, but laboratories lacked capacity, specificity, and sensitivity for JEV and YFV. Three of the viruses in this panel emerged and transiently circulated in Europe: CHIKV, ZIKV, and DENV. Molecular detection was excellent for those viruses, but <50% is accurate for the remainder of the panel. With the possibility or continuation of imported cases and a growing global concern about climate change and vector expansion, progress toward rapid, accurate mosquito-borne virus diagnostics in Europe is recommended, as well as regular EQAs to monitor it.IMPORTANCEThe external quality assessment (EQA) focused on Aedes-borne viruses: chikungunya virus (CHIKV), dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus (YFV). Japanese encephalitis virus, an orthoflavivirus that is spread by mosquito species belonging to the genus Culex, was included in the quality assessment as well. CHIKV, DENV, and ZIKV have proven potential for transient and limited circulation in Europe upon introduction of viremic travelers returning to Aedes albopictus-endemic regions. Results of this EQA were excellent for those viruses, but <50% is accurate for the remainder of the panel (YFV and Japanese encephalitis virus). Considering imported cases and the threat of climate change and competent vector expansion, progress toward rapid, accurate mosquito-borne virus diagnostics in Europe is recommended.

Modelling the seasonal dynamics of Aedes albopictus populations using a spatio-temporal stacked machine learning model

Various modelling techniques are available to understand the temporal and spatial variations of the phenology of species. Scientists often rely on correlative models, which establish a statistical relationship between a response variable (such as species abundance or presence-absence) and a set of predominantly abiotic covariates. The choice of the modeling approach, i.e., the algorithm, is itself a significant source of variability, as different algorithms applied to the same dataset can yield disparate outcomes. This inter-model variability has led to the adoption of ensemble modelling techniques, among which stacked generalisation, which has recently demonstrated its capacity to produce robust results. Stacked ensemble modelling incorporates predictions from multiple base learners or models as inputs for a meta-learner. The meta-learner, in turn, assimilates these predictions and generates a final prediction by combining the information from all the base learners. In our study, we utilized a recently published dataset documenting egg abundance observations of Aedes albopictus collected using ovitraps. and a set of environmental predictors to forecast the weekly median number of mosquito eggs using a stacked machine learning model. This approach enabled us to (i) unearth the seasonal egg-laying dynamics of Ae. albopictus for 12 years; (ii) generate spatio-temporal explicit forecasts of mosquito egg abundance in regions not covered by conventional monitoring initiatives. Our work establishes a robust methodological foundation for forecasting the spatio-temporal abundance of Ae. albopictus, offering a flexible framework that can be tailored to meet specific public health needs related to this species.

Spatiotemporal analysis of mosquito-borne infections and mosquito vectors in mainland Portugal

BACKGROUND

The incidence of mosquito-borne infections has increased worldwide. Mainland Portugal's characteristics might favour the (re)emergence of mosquito-borne diseases. This study aimed to characterize the spatial distribution of vectors and notification rates of imported cases of mosquito-borne infections in mainland Portugal and demarcate the areas where these geographies overlap.

METHODS

We used data from imported cases of malaria, dengue and Zika from 2009 to 2019, alongside data on the presence of mosquitoes capable of potentially transmitting these diseases at the municipality level (2009-2018). This data was provided by the National Epidemiological Surveillance System and Regional Health Administrations, based on reports from the Vector Surveillance Network. While the mosquitoes in question do not currently transmit these diseases, they have the potential to do so if there is a significant increase in pathogen circulation. A spatial cluster analysis was performed using the univariate Local Moran Index, the Bivariate Moran Local Index and the Mann-Kendall method.

RESULTS

We found significant spatial variability in both notification rates of imported mosquito-borne infections and the distribution of competent mosquito species. We identified clusters of simultaneous high concentrations of vectors and imported cases of malaria in Condeixa-a-Nova (Coimbra), Cuba (Beja), Santiago do Cacém (Setúbal), Albufeira and São Brás de Alportel (Faro), most located on the Southern coast of Portugal. For dengue, we detected clusters of simultaneous high concentrations of vectors and imported cases in Paredes, in the Northern region, and Faro, on the southern coast. For Zika, no clusters were identified.

CONCLUSION

This study identified areas with high notification rates of imported cases and the presence of competent vectors. Surveillance, control, and awareness efforts are essential, as these areas may present higher risks for local transmission in the future if ecological conditions remain or become suitable, potentially evolving into foci for disease transmission.

Clash of mosquito wings: Larval interspecific competition among the mosquitoes, Culex pipiens, Aedes albopictus and Aedes aegypti reveals complex population dynamics in shared habitats

Globalisation, climate change and international trade are the factors contributing to the spread of Aedes albopictus (Diptera: Culicidae) and Ae. aegypti into new areas. In newly invaded habitats, these non-native species can serve as arbovirus disease vectors or increase the risk of disease spill over. These mosquitoes continue to emerge in new areas where they have or will have overlapping ranges with other resident mosquito species. The study investigates how invasive Aedes mosquitoes compete with the native Culex pipiens in Türkiye, which might affect the overall mosquito population dynamics and disease transmission risks. Both Aedes species exhibited contrasting responses to interspecific competition with Cx. pipiens. While Ae. albopictus suffers reduced emergence primarily in larger containers with abundant food, Ae. aegypti surprisingly thrives in mixed cultures under all food conditions. Adult Cx. pipiens emergence drops by half against Ae. albopictus and under specific conditions with Ae. aegypti. Competition influences mosquito size differently across species and life stages. Culex pipiens females grow larger when competing with Ae. aegypti, potentially indicating resource advantage or compensatory strategies. However, Ae. albopictus size shows more nuanced responses, suggesting complex interactions at play. Understanding how invasive and native mosquitoes interact with each other can provide insights into how they adapt and coexist in shared habitats. This knowledge can inform effective control strategies. The study highlights the differential responses of invasive Aedes species and the potential for managing populations based on their competitive interactions with the native Cx. pipiens. It can contribute to improved monitoring and prediction systems for the spread of invasive mosquitoes and the associated disease risks.

Wolbachia incompatible insect technique program optimization over large spatial scales using a process-based model of mosquito metapopulation dynamics

BACKGROUND

Wolbachia incompatible insect technique (IIT) programs have been shown in field trials to be highly effective in suppressing populations of mosquitoes that carry diseases such as dengue, chikungunya, and Zika. However, the frequent and repeated release of Wolbachia-infected male mosquitoes makes such programs resource-intensive. While the need for optimization is recognized, potential strategies to optimize releases and reduce resource utilization have not been fully explored.

RESULTS

We developed a process-based model to study the spatio-temporal metapopulation dynamics of mosquitoes in a Wolbachia IIT program, which explicitly incorporates climatic influence in mosquito life-history traits. We then used the model to simulate various scale-down and redistribution strategies to optimize the existing program in Singapore. Specifically, the model was used to study the trade-offs between the intervention efficacy outcomes and resource requirements of various release program strategies, such as the total number of release events and the number of mosquitoes released. We found that scaling down releases in existing sites from twice a week to only once a week yielded small changes in suppression efficacy (from 87 to 80%), while requiring 44% fewer mosquitoes and release events. Additionally, redistributing mosquitoes from already suppressed areas and releasing them in new areas once a week led to a greater total suppressive efficacy (83% compared to 61%) while also yielding a 16% and 14% reduction in the number of mosquitoes and release events required, respectively.

CONCLUSIONS

Both scale-down and redistribution strategies can be implemented to significantly reduce program resource requirements without compromising the suppressive efficacy of IIT. These findings will inform planners on ways to optimize existing and future IIT programs, potentially allowing for the wider adoption of this method for mosquito-borne disease control.

Divergence of discrete- versus continuous-time calculations of the temperature dependence of maximum population growth rate

The temperature dependence of population fitness( r m ) is key to predicting ectotherm responses to climatic change. Discrete-time matrix projection models (MPMs) are used to calculater m because they capture variation in its underlying life-history trait values and time delays inherent in those traits. However, MPM calculations can be laborious and do not capture time's continuous nature. More complex approaches for calculating temperature-dependentr m may be more accurate but they are notoriously difficult to parameterise. Ordinary differential equation-based models (ODEMs) offer a relatively tractable alternative of intermediate complexity, but it is unknown whether they broadly agree with MPM calculations when environmental variation is introduced. Here we investigate differences in the predicted temperature dependence ofr m obtained from an ODEM with those calculated from MPMs using temperature- and resource dependent life-history trait data for the disease vector, Aedes aegypti. We show that the level of agreement between discrete- and continuous-time representations of temperature-dependentr m can vary with resource availability and is extremely sensitive to juvenile survival characterisations. This finding suggests that ODEMs can only provide comparabler m predictions to standard methods when resources are not limiting, questioning the ability of existing mathematical models to reliably predict arthropod responses to environmental variation.

The One Health approach in urban ecosystem rehabilitation: An evidence-based framework for designing sustainable cities

Rapid urbanization has led to negative, and sometimes unintended, consequences on biodiversity and human health. While cities offer numerous advantages in meeting the basic needs of a growing population, they also pose less apparent and longer-term health costs. To address the multifaceted impacts of urbanization, an evidence-based design framework for establishing mitigation and regeneration actions is essential. Via a "One Health" approach, this perspective provides recommendations and strategies for the urban ecosystem rehabilitation of future cities, placing biodiversity and ecosystem services at the core of designing healthy and sustainable urban spaces. The framework we propose is based on a Hub and Spoke model to integrate diverse perspectives from public and private sectors and declined in a six-building-blocks structure. This will ensure that efforts are sustainable, health-centered, socially inclusive, and grounded in high-quality data, reinforcing the essential connection between healthy environments and thriving communities.

Emerging Infectious Diseases and the Eye: Ophthalmic Manifestations, Pathogenesis, and One Health Perspectives

Infectious diseases may lead to ocular complications including uveitis, an ocular inflammatory condition with potentially sight-threatening sequelae, and conjunctivitis, inflammation of the conjunctiva. Emerging infectious pathogens with known ocular findings include Ebola virus, Zika virus, Avian influenza virus, Nipah virus, severe acute respiratory syndrome coronaviruses, and Dengue virus. Re-emerging pathogens with ocular findings include Toxoplasma gondii and Plasmodium species that lead to malaria. The concept of One Health involves a collaborative and interdisciplinary approach to achieve optimal health outcomes by combining human, animal, and environmental health factors. This approach examines the interconnected and often complex human-pathogen-intermediate host interactions in infectious diseases that may also result in ocular disease, including uveitis and conjunctivitis. Through a comprehensive review of the literature, we review the ophthalmic findings of emerging infectious diseases, pathogenesis, and One Health perspectives that provide further insight into the disease state. While eye care providers and vision researchers may often focus on key local aspects of disease process and management, additional perspective on host-pathogen-reservoir life cycles and transmission considerations, including environmental factors, may offer greater insight to improve outcomes for affected individuals and stakeholders.

Using UAV images and deep learning in investigating potential breeding sites of Aedes albopictus

Aedes albopictus (Diptera: Culicidae) plays a crucial role as a vector for mosquito-borne diseases like dengue and zika. Given the limited availability of effective vaccines, the prevention of Aedes-borne diseases mainly relies on extensive efforts in vector surveillance and control. In multiple mosquito control methods, the identification and elimination of potential breeding sites (PBS) for Aedes are recognized as effective methods for population control. Previous studies utilizing unmanned aerial vehicles (UAVs) and deep learning to identify PBS have primarily focused on large, regularly-shaped containers. However, there has been a small amount of empirical research into their practical application in the field. We have thus constructed a PBS dataset specifically tailored for Ae. albopictus, including items such as buckets, bowls, bins, aquatic plants, jars, lids, pots, boxes, and sinks that were common in the Yangtze River Basin in China. Then, a YOLO v7 model for identifying these PBS was developed. Finally, we recognized and labeled the area with the highest PBS density, as well as the subarea with the most urgent need for source reduction in the empirical region, by calculating the kernel density value. Based on the above research, we proposed a UAV-AI-based methodological framework to locate the spatial distribution of PBS, and conducted empirical research on Jinhulu New Village, a typical model community. The results revealed that the YOLO v7 model achieved an excellent result on the F1 score and mAP(both above 0.99), with 97% of PBS correctly located. The predicted distribution of different PBS categories in each subarea was completely consistent with true distribution; the five houses with the most PBS were correctly located. The results of the kernel density map indicate the subarea 4 with the highest density of PBS, where PBS needs to be removed or destroyed with immediate effect. These results demonstrate the reliability of the prediction results and the feasibility of the UAV-AI-based methodological framework. It can minimize repetitive labor, enhance efficiency, and provide guidance for the removal and destruction of PBS. The research can shed light on the investigation of mosquito PBS investigation both methodologically and practically.

Integrated One Health strategies in Dengue

Zoonoses have rapidly spread globally, necessitating the implementation of vaccination strategies as a control measure. Emerging and re-emerging vector-borne diseases are among the major global public health concerns. Dengue, a zoonotic viral infection transmitted to humans by a vector, the Aedes mosquito, is a severe global health problem. Dengue is a serious tropical infectious disease, second only to malaria, causing around 25,000 deaths each year. The resurgence of Dengue is mainly due to climate change, demographic transitions and evolving social dynamics. The development of an effective vaccine against Dengue has proven to be a complex undertaking due to four different viral serotypes with distinct antigenic profiles. This review highlights the urgent need to address the dengue threat by exploring the application of biotechnological and -OMICS sciences.

The potential habitat and environmental fitness change of Aedes albopictus in Western Eurasia for 2081-2100

BACKGROUND OBJECTIVES

The range of Aedes albopictus, the most important vector mosquito in Western Eurasia is growing due to climate change. However, it is not known how it will influence the habitats occupied by the species and its environmental fitness within its future range.

METHODS

To study this question, the habitat characteristic of the mosquito was investigated for 2081-2100.

RESULTS

The models suggest a notable future spread of the mosquito in the direction of Northern Europe and the parallel northward and westward shift of the southern and eastern potential occurrences of the mosquito. The models suggest a notable increase in generation numbers in the warmest quarter, which can reach 4-5 generations in the peri-Mediterranean region. However, both the joint survival rate of larvae and pupae and the number of survival days of adults in the warmest quarter exhibit decreasing values, as does the potential disappearance of the mosquito in the southern regions of Europe and Asia Minor, along with the growing atmospheric CO2 concentration-based scenarios.

INTERPRETATION CONCLUSION

While in 1970-2000 Aedes albopictus mainly occupied the hot and warm summer temperate regions of Europe, the species will inhabit dominantly the cool summer temperate (oceanic) and the humid continental climate territories of North and North-Eastern Europe in 2081-2100.

The Perpetual Vector Mosquito Threat and Its Eco-Friendly Nemeses

Mosquitoes are the most notorious arthropod vectors of viral and parasitic diseases for which approximately half the world's population, ~4,000,000,000, is at risk. Integrated pest management programs (IPMPs) have achieved some success in mitigating the regional transmission and persistence of these diseases. However, as many vector-borne diseases remain pervasive, it is obvious that IPMP successes have not been absolute in eradicating the threat imposed by mosquitoes. Moreover, the expanding mosquito geographic ranges caused by factors related to climate change and globalization (travel, trade, and migration), and the evolution of resistance to synthetic pesticides, present ongoing challenges to reducing or eliminating the local and global burden of these diseases, especially in economically and medically disadvantaged societies. Abatement strategies include the control of vector populations with synthetic pesticides and eco-friendly technologies. These "green" technologies include SIT, IIT, RIDL, CRISPR/Cas9 gene drive, and biological control that specifically targets the aquatic larval stages of mosquitoes. Regarding the latter, the most effective continues to be the widespread use of Lysinibacillus sphaericus (Ls) and Bacillus thuringiensis subsp. israelensis (Bti). Here, we present a review of the health issues elicited by vector mosquitoes, control strategies, and lastly, focus on the biology of Ls and Bti, with an emphasis on the latter, to which no resistance has been observed in the field.

History of research on Aedes albopictus (Diptera: Culicidae) in Europe: approaching the world's most invasive mosquito species from a bibliometric perspective

The Asian tiger mosquito, Aedes albopictus (Skuse), is an invasive species native to Southeast Asia. This insect, which is an important vector of arbovirus such as dengue, Zika, and chikungunya, has spread rapidly to several parts of the world over the last few decades. This study employed a bibliometric approach to explore, for the first time, Ae. albopictus research activity and output in Europe. We used the Web of Science Core Collection data source to characterize the current scientific research. A total of 903 publications from 1973 to 2022 were retrieved. We also provided a comprehensive analysis by year of publication; distribution by most productive European countries, institutions, and authors; collaboration networks; research topics; most productive journals; and most cited publications. Results showed a notable increase in the number of studies after the chikungunya virus outbreak in Northeast Italy in 2007. More than 60% of these publications across the entire European continent originated from France and Italy. Research output related to 'population and community ecology' topics was significantly high. The most common type of collaboration was national, which occurred between institutions in the same European country. By providing an overview of Ae. albopictus research in Europe, this work contributes to upcoming debates, decision-making, planning on research and development, and public health strategies on the continent and worldwide.

Mitigating the effects of climate change on human health with vaccines and vaccinations

Climate change represents an unprecedented threat to humanity and will be the ultimate challenge of the 21st century. As a public health consequence, the World Health Organization estimates an additional 250,000 deaths annually by 2030, with resource-poor countries being predominantly affected. Although climate change's direct and indirect consequences on human health are manifold and far from fully explored, a growing body of evidence demonstrates its potential to exacerbate the frequency and spread of transmissible infectious diseases. Effective, high-impact mitigation measures are critical in combating this global crisis. While vaccines and vaccination are among the most cost-effective public health interventions, they have yet to be established as a major strategy in climate change-related health effect mitigation. In this narrative review, we synthesize the available evidence on the effect of climate change on vaccine-preventable diseases. This review examines the direct effect of climate change on water-related diseases such as cholera and other enteropathogens, helminthic infections and leptospirosis. It also explores the effects of rising temperatures on vector-borne diseases like dengue, chikungunya, and malaria, as well as the impact of temperature and humidity on airborne diseases like influenza and respiratory syncytial virus infection. Recent advances in global vaccine development facilitate the use of vaccines and vaccination as a mitigation strategy in the agenda against climate change consequences. A focused evaluation of vaccine research and development, funding, and distribution related to climate change is required.

Increasing the Awareness of Under-Diagnosed Tropical Cases of Dengue in Romania

Global travelling increases every year and according to a report released during the COVID-19 pandemic by the UN World Tourism Organization, international travel doubled in 2022, compared to levels in 2021. his fact led also to travel-imported cases of arboviral infections and physicians are often confronted with tropical diseases, such as dengue or chikungunya. Since there is are no pathognomonic cues for these tropical illnesses, early diagnosis is still a big challenge and it depends on many factors, such as exposure risk factors, the epidemiological context, the incubation period, and the wide spectrum of differential diagnoses, including cosmopolitan or exotic infections. Since the clinical presentation of dengue is not typical and there are other febrile illnesses similar to arboviral diseases, misdiagnosis is common even among experienced doctors. Differential diagnosis needs up to date knowledge considering the short viraemic period, the antibody cross-reactivity, and the traps in recognising the nonspecific symptom picture. We present two cases of Dengue diagnosed in Romania which were initially clinically misconstrued, despite the characteristic symptom picture. The main purpose is to increase the level of awareness and to underline the difficulties that clinicians face in recognizing travel-related imported dengue virus disease.

The Ongoing Epidemic of West Nile Virus in Greece: The Contribution of Biological Vectors and Reservoirs and the Importance of Climate and Socioeconomic Factors Revisited

Emerging infectious diseases have inflicted a significant health and socioeconomic burden upon the global population and governments worldwide. West Nile virus, a zoonotic, mosquito-borne flavivirus, was originally isolated in 1937 from a febrile patient in the West Nile Province of Uganda. It remained confined mainly to Africa, the Middle East, and parts of Europe and Australia until 1999, circulating in an enzootic mosquito-bird transmission cycle. Since the beginning of the 21st century, a new, neurotropic, more virulent strain was isolated from human outbreaks initially occurring in North America and later expanding to South and South-eastern Europe. Since 2010, when the first epidemic was recorded in Greece, annual incidence has fluctuated significantly. A variety of environmental, biological and socioeconomic factors have been globally addressed as potential regulators of the anticipated intensity of the annual incidence rate; circulation within the zoonotic reservoirs, recruitment and adaptation of new potent arthropod vectors, average winter and summer temperatures, precipitation during the early summer months, and socioeconomic factors, such as the emergence and progression of urbanization and the development of densely populated areas in association with insufficient health policy measures. This paper presents a review of the biological and socioenvironmental factors influencing the dynamics of the epidemics of West Nile virus (WNV) cases in Greece, one of the highest-ranked European countries in terms of annual incidence. To date, WNV remains an unpredictable opponent as is also the case with other emerging infectious diseases, forcing the National Health systems to develop response strategies, control the number of infections, and shorten the duration of the epidemics, thus minimizing the impact on human and material resources.

Suppression Trial through an Integrated Vector Management of Aedes albopictus (Skuse) Based on the Sterile Insect Technique in a Non-Isolated Area in Spain

In recent years, Aedes albopictus (Skuse, 1984) has expanded its distribution globally due to its high ecological plasticity. This expansion has increased the population's susceptibility to contracting diseases such as dengue, Zika, and chikungunya, among others, which are transmitted by this mosquito species. In the absence of effective control methods, the application of the sterile insect technique (SIT) is proposed as part of an integrated vector management (IVM) program. From 2007 to 2020, this strategy has been tested in a non-isolated mosquito population urban area of 45 ha, representative of the municipalities of the Valencian region (Spain). The population levels of adult females and eggs collected in the traps have been reduced by 70-80% compared to the control area, demonstrating its efficacy in reducing mosquito populations. This work analyzes the impact of the migration of the wild mosquito population from the peri-urban area to the urban core.

RNA interference to combat the Asian tiger mosquito in Europe: A pathway from design of an innovative vector control tool to its application

The Asian tiger mosquito Aedes albopictus is currently spreading across Europe, facilitated by climate change and global transportation. It is a vector of arboviruses causing human diseases such as chikungunya, dengue hemorrhagic fever and Zika fever. For the majority of these diseases, no vaccines or therapeutics are available. Options for the control of Ae. albopictus are limited by European regulations introduced to protect biodiversity by restricting or phasing out the use of pesticides, genetically modified organisms (GMOs) or products of genome editing. Alternative solutions are thus urgently needed to avoid a future scenario in which Europe faces a choice between prioritizing human health or biodiversity when it comes to Aedes-vectored pathogens. To ensure regulatory compliance and public acceptance, these solutions should preferably not be based on chemicals or GMOs and must be cost-efficient and specific. The present review aims to synthesize available evidence on RNAi-based mosquito vector control and its potential for application in the European Union. The recent literature has identified some potential target sites in Ae. albopictus and formulations for delivery. However, we found little information concerning non-target effects on the environment or human health, on social aspects, regulatory frameworks, or on management perspectives. We propose optimal designs for RNAi-based vector control tools against Ae. albopictus (target product profiles), discuss their efficacy and reflect on potential risks to environmental health and the importance of societal aspects. The roadmap from design to application will provide readers with a comprehensive perspective on the application of emerging RNAi-based vector control tools for the suppression of Ae. albopictus populations with special focus on Europe.

Chikungunya Virus Infection and Gonotrophic Cycle Shape Aedes aegypti Oviposition Behavior and Preferences

Targeting gravid females through chemical lures is a promising strategy in vector control; however, it requires the understanding of the factors susceptible to alter female oviposition behavior. Here, we evaluated the effect of infection with chikungunya virus (CHIKV) and the number of gonotrophic cycles (GCs) on oviposition activity in A. aegypti. Dual choice oviposition assays were performed, where dodecanoic acid, pentadecanoic acid, n-heneicosane and a Sargasssum fluitans (Børgesen) Børgesen extract were tested in uninfected females and females infected with CHIKV, at the 1st and 2nd GC. Infected females displayed a lower percentage of oviposition and a higher number of eggs laid at the 1st GC. Then, the combined effects of GC and CHIKV were observed on oviposition preferences, with a chemical-dependent effect. For instance, the deterrent effect of n-heneicosane and pentadecanoic acid increased at the 2nd GC in infected females. These results allow for a deeper understanding of the mechanisms involved in oviposition site selection and highlight the need for taking into account physiological stage changes to increase the control programs' efficacy.

Chikungunya fever

Chikungunya virus is widespread throughout the tropics, where it causes recurrent outbreaks of chikungunya fever. In recent years, outbreaks have afflicted populations in East and Central Africa, South America and Southeast Asia. The virus is transmitted by Aedes aegypti and Aedes albopictus mosquitoes. Chikungunya fever is characterized by severe arthralgia and myalgia that can persist for years and have considerable detrimental effects on health, quality of life and economic productivity. The effects of climate change as well as increased globalization of commerce and travel have led to growth of the habitat of Aedes mosquitoes. As a result, increasing numbers of people will be at risk of chikungunya fever in the coming years. In the absence of specific antiviral treatments and with vaccines still in development, surveillance and vector control are essential to suppress re-emergence and epidemics.

Assessing Biodiversity Conditions in Cocoa Agroforests with a Rapid Assessment Method: Outcomes from a Large-Scale Application in Ghana

Cocoa fields in West Africa traditionally kept other tree species to provide shade for cocoa trees and obtain food and other products. Measuring other trees is paramount to monitoring environmental conditions in cocoa agroforests, but it has been difficult to apply at a large scale. This study presents the results of a rapid assessment method applied in Ghana, developed to measure non-cocoa tree characteristics based on easily observed parameters using sample surveys and mapping tools. We collected data from over 8700 cocoa farms and evaluated their biodiversity performance based on 6 indicators classified according to recommended thresholds to benefit biodiversity conditions. Our results show that species richness, shade cover, and potential for tree succession have the lowest proportions of fields with the recommended levels, with variations among regions and districts. The methodological procedure allowed us to identify priority areas and indicators falling behind desirable thresholds, which can inform training and management approaches regarding biodiversity-friendly practices in cocoa fields tailored to the needs of the farmers. The analysis procedure was developed with open-access automated routines, allowing for easy updates and replication to other areas, as well as for other commodities, enabling comparisons at different spatial scales and contributing to monitoring biodiversity over time.

Climate change and Aedes albopictus risks in China: current impact and future projection

BACKGROUND

Future distribution of dengue risk is usually predicted based on predicted climate changes using general circulation models (GCMs). However, it is difficult to validate the GCM results and assess the uncertainty of the predictions. The observed changes in climate may be very different from the GCM results. We aim to utilize trends in observed climate dynamics to predict future risks of Aedes albopictus in China.

METHODS

We collected Ae. albopictus surveillance data and observed climate records from 80 meteorological stations from 1970 to 2021. We analyzed the trends in climate change in China and made predictions on future climate for the years 2050 and 2080 based on trend analyses. We analyzed the relationship between climatic variables and the prevalence of Ae. albopictus in different months/seasons. We built a classification tree model (based on the average of 999 runs of classification and regression tree analyses) to predict the monthly/seasonal Ae. albopictus distribution based on the average climate from 1970 to 2000 and assessed the contributions of different climatic variables to the Ae. albopictus distribution. Using these models, we projected the future distributions of Ae. albopictus for 2050 and 2080.

RESULTS

The study included Ae. albopictus surveillance from 259 sites in China found that winter to early spring (November-February) temperatures were strongly correlated with Ae. albopictus prevalence (prediction accuracy ranges 93.0-98.8%)-the higher the temperature the higher the prevalence, while precipitation in summer (June-September) was important predictor for Ae. albopictus prevalence. The machine learning tree models predicted the current prevalence of Ae. albopictus with high levels of agreement (accuracy > 90% and Kappa agreement > 80% for all 12 months). Overall, winter temperature contributed the most to Ae. albopictus distribution, followed by summer precipitation. An increase in temperature was observed from 1970 to 2021 in most places in China, and annual change rates varied substantially from -0.22 ºC/year to 0.58 ºC/year among sites, with the largest increase in temperature occurring from February to April (an annual increase of 1.4-4.7 ºC in monthly mean, 0.6-4.0 ºC in monthly minimum, and 1.3-4.3 ºC in monthly maximum temperature) and the smallest in November and December. Temperature increases were lower in the tropics/subtropics (1.5-2.3 ºC from February-April) compared to the high-latitude areas (2.6-4.6 ºC from February-April). The projected temperatures in 2050 and 2080 by this study were approximately 1-1.5 °C higher than those projected by GCMs. The estimated current Ae. albopictus risk distribution had a northern boundary of north-central China and the southern edge of northeastern China, with a risk period of June-September. The projected future Ae. albopictus risks in 2050 and 2080 cover nearly all of China, with an expanded risk period of April-October. The current at-risk population was estimated to be 960 million and the future at-risk population was projected to be 1.2 billion.

CONCLUSIONS

The magnitude of climate change in China is likely to surpass GCM predictions. Future dengue risks will expand to cover nearly all of China if current climate trends continue.

The Risk of Emerging of Dengue Fever in Romania, in the Context of Global Warming

(1) Background: Few studies to date have assessed the influences induced by climate change on the spatial distribution and population abundance of Aedes albopictus using the latest climate scenarios. In this study, we updated the current distribution of Ae. albopictus mosquitoes and evaluated the changes in their distribution under future climate conditions, as well as the risk of dengue virus emergence in Romania. (2) Methods: Under the two scenarios: High scenario (HS) when no drastic measures to reduce the effects of global warming will be taken, or they are not effective and low scenario (LS) when very stringent greenhouse control measures will be implemented. (3) Results: The results estimate an increase in temperatures in Romania of up to 2.6 °C in HS and up to 0.4 °C in LS, with an increase in the period of virus replication within the vector from June to October in HS and from May to September in LS. Moreover, in 2022, Ae. albopictus was reported in a new county, where it was not identified at the last monitoring in 2020. (4) Conclusions: The rapid spread of this invasive species and the need to implement monitoring and control programs for the Aedes population in Romania are emphasized.

dynamAedes: a unified modelling framework for invasive Aedes mosquitoes

Mosquito species belonging to the genus Aedes have attracted the interest of scientists and public health officers because of their capacity to transmit viruses that affect humans. Some of these species were brought outside their native range by means of trade and tourism and then colonised new regions thanks to a unique combination of eco-physiological traits. Considering mosquito physiological and behavioural traits to understand and predict their population dynamics is thus a crucial step in developing strategies to mitigate the local densities of invasive Aedes populations. Here, we synthesised the life cycle of four invasive Aedes species (Ae. aegypti, Ae. albopictus, Ae. japonicus and Ae. koreicus) in a single multi-scale stochastic modelling framework which we coded in the R package dynamAedes. We designed a stage-based and time-discrete stochastic model driven by temperature, photo-period and inter-specific larval competition that can be applied to three different spatial scales: punctual, local and regional. These spatial scales consider different degrees of spatial complexity and data availability by accounting for both active and passive dispersal of mosquito species as well as for the heterogeneity of the input temperature data. Our overarching aim was to provide a flexible, open-source and user-friendly tool rooted in the most updated knowledge on the species' biology which could be applied to the management of invasive Aedes populations as well as to more theoretical ecological inquiries.

Public Health Aspects of Climate Change Adaptation in Three Cities: A Qualitative Study

Climate change presents an unprecedented public health challenge as it has a great impact on population health outcomes across the global population. The key to addressing these health challenges is adaptation carried out in cities through collaboration between institutions, including public health ones. Through semi-structured interviews (n = 16), this study investigated experiences and perceptions of what public health aspects are considered by urban and public health planners and researchers when planning climate change adaptation in the coastal cities of Söderhamn (Sweden), Porto (Portugal) and Navotas (the Philippines). Results of the thematic analysis indicated that participating stakeholders were aware of the main climate risks threatening their cities (rising water levels and flooding, extreme temperatures, and air pollution). In addition, the interviewees talked about collaboration with other sectors, including the public health sector, in implementing climate change adaptation plans. However, the inclusion of the public health sector as a partner in the process was identified in only two cities, Navotas and Porto. Furthermore, the study found that there were few aspects pertaining to public health (water and sanitation, prevention of heat-related and water-borne diseases, and prevention of the consequences associated with heat waves in vulnerable groups such as children and elderly persons) in the latest climate change adaptation plans posted on each city's website. Moreover, participants pointed to different difficulties: insufficient financial resources, limited intersectoral collaboration for climate change adaptation, and lack of involvement of the public health sector in the adaptation processes, especially in one of the cities in which climate change adaptation was solely the responsibility of the urban planners. Studies using larger samples of stakeholders in larger cities are needed to better understand why the public health sector is still almost absent in efforts to adapt to climate change.

Lethal effect of blue light on Asian tiger mosquito, Aedes albopictus (Diptera: Culicidae)

In our previous studies, we found that blue light has a lethal effect on various insect species and demonstrated that the most effective wavelength to control the hygiene pest, the mosquito, Culex pipiens form molestus (Diptera: Culicidae), is ~ 420 nm through all developmental stages. The genera Aedes and Culex include many globally crucial hygiene pest species that transmit serious diseases to humans and animals. However, effective lethal wavelengths have been shown to differ among insect species. In this study, we investigated the lethal effects of blue light on the Asian tiger mosquito, Aedes albopictus, using light-emitting diodes. Blue-light irradiation had a lethal effect on the larvae, pupae, and adults of Ae. albopictus. In particular, the 417-nm blue-light wavelength had a strong lethal effect on the larvae, showing 100% mortality before pupation at the photon flux density of 10 × 10¹⁸ photons·m^-2·s^-1. In contrast, no blue-light wavelength had a lethal effect on the eggs. Moreover, the 417-nm wavelength had the strongest effect on the pupae among the tested blue-light wavelengths. Our findings indicate that ~ 420 nm is the most promising blue-light wavelength to control populations of Ae. albopictus and C. pipiens f. molestus.

Chikungunya Encephalitis: an Inconsistently Reported Headache and Cause of Death in Patients with Pre-Existing Conditions

Chikungunya virus (CHIKV) is an alphavirus of the family Togaviridae with outbreaks occurring across Africa, Asia, parts of Europe, and South and Central America. There are three main lineages of CHIKV, including the West African lineage, the East Central South African (ECSA) lineage, and the Asian lineage. While CHIKV infection usually results in a self-limited febrile illness, there have been reports of concerning neurological manifestations, including encephalitis. Herein we discuss findings of over 700 cases of CHIKV encephalitis and risk factors for death. Additionally, we examined the genotypes of CHIKV associated with encephalitis and found that both the Asian and ECSA lineages were responsible for encephalitis but not the West African lineage. Protein analysis of consensus sequences of CHIKV strains associated with encephalitis identified mutations in the nsP1, nsP2, and nsP3 proteins. Reports and manuscripts of CHIKV encephalitis were inconsistent in reporting viral, demographic, and clinical features which complicated the delineation of risk factors associated with the disease and viral evolution. As climate change contributes to the range expansion of natural vectors, it is important for researchers and clinicians to consistently report patient and viral data to facilitate research and countermeasures for the ecology and epidemiology of CHIKV due to the lack of a targeted treatment or vaccine.

Establishment, Genetic Diversity, and Habitat Suitability of Aedes albopictus Populations from Ecuador

Simple Summary

The tiger mosquito, Aedes albopictus, is a vector of multiple viral diseases. Therefore, it is crucial to understand its distribution and the genetic diversity of Ecuadorian populations. This study used a genetic marker to understand aspects of the dynamics of the Ecuadorian populations of Aedes albopictus from five sites along the coastal, Amazon basin, and Andean lowland regions. Our results evidence two haplotypes within the Ecuadorian populations. Haplotype 1 was found in the coastal regions and Amazon basin, while haplotype 2 was found in the northeastern lowlands. Worldwide, haplotype 1 has been found in 21 countries in temperate and tropical habitats, and haplotype 2 has been found in five countries in tropical habitats. Hence, a difference in adaptation traits could be speculated between both haplotypes. Our study presents a prediction model that shows the suitable habitats for Aedes albopictus in Ecuador. Our results showed that the vector could spread through all country regions, including the Galapagos Islands. Thus, understanding the different aspects of the local populations can help establish better vector surveillance and control strategies.

Abstract

Aedes albopictus, also known as the tiger mosquito, is widespread worldwide across tropical, subtropical, and temperate regions. This insect is associated with the transmission of several vector-borne diseases, and, as such, monitoring its distribution is highly important for public health. In Ecuador, Ae. albopictus was first reported in 2017 in Guayaquil. Since then, the vector has been identified in the Northeastern lowlands and the Amazon basin. This study aims to determine the genetic diversity of Ecuadorian populations of Ae. albopictus through the analysis of the mitochondrial gene COI and to describe the potential distribution areas of this species within the country. The genetic diversity was determined by combining phylogenetic and population genetics analyses of five localities in Ecuador. Results showed two haplotypes in the Ecuadorian populations of Ae. albopictus. Haplotype 1 (H1) was found in the coastal and Amazon individuals, while haplotype 2 (H2) was only found in the three northeastern lowlands sites. In a worldwide context, H1 is the most widespread in 21 countries with temperate and tropical habitats. In contrast, H2 distribution is limited to five countries in tropical regions, suggesting fewer adaptation traits. Our prediction model showed a suitable habitat for Ae. albopictus in all regions (coastal, Amazon basin, and Andean lowland regions and the Galápagos Islands) of Ecuador. Hence, understanding different aspects of the vector can help us implement better control strategies for surveillance and vectorial control in Ecuador.