Vector-borne Transmission Research Articles

VEClim: An early warning decision support system for climate-sensitive vector activity and vector-borne disease risk assessment

Global warming and environmental changes affect vector species and vector-borne pathogen transmission, presenting significant public health challenges. We developed the Climate-Driven Vector-Borne Disease Risk Assessment platform (VEClim) to support early warning systems and decision support mechanisms, aiding the planning of effective vector control and outbreak management strategies. VEClim employs climate-sensitive structured population modelling, incorporating physiological processes driven by meteorological and environmental factors. A user-friendly web-based Geographic Information System (GIS) delivers a versatile interface to improve accessibility to the models and present short-, medium-, and long-range predictions of habitat suitability, vector activity, and disease risk and impact. The initial release of VEClim presents an in-depth assessment of the seasonal dynamics of Aedes albopictus, also known as the Asian tiger mosquito, and the associated risk of chikungunya virus transmission. This analysis compares three decades, i.e., historical (1980–1990), recent (2010–2020), and future (2090–2100), in terms of seasonal and geospatial averages. The results indicate persistent activity of the vector along the Mediterranean coast and a global northward shift of disease risk due to climate change. The VEClim platform is operationally maintained at The Cyprus Institute and is permanently available via its dedicated domain: veclim.com. VEClim offers environmental datasets, an open-source toolkit for researchers and modellers, and insights for public health officials and decision-makers.

The Impacts of Climate Change on Dengue Transmission

Objective: The objective of this research is to conduct a bibliometric analysis of scientific publications on the relationship between climate change and dengue transmission in the Scopus database, covering the period from 2014 to 2023. Method: This is an exploratory, descriptive, and quantitative research with a bibliometric approach. Data collection was performed in the Scopus database, following the inclusion criteria: journal articles in English published between 2014 and 2023 and accessible in the database, and exclusion criteria: duplicate articles, inaccessible articles, or review articles. Results and Discussion: The results show no increase in the number of articles over the years. Regarding the authors, Lowe, R., and Ryan, S. J. had the highest number of published articles and citations. Among countries, the United States stood out with the highest number of articles, while Brazil produced ten times fewer articles than the United States. Additionally, concerning climatic factors, three stood out: temperature, precipitation, and humidity, mainly related to increased vector density and mosquito incidence, higher virus transmission, reduced virus incubation time, among other aspects. Research Implications: There is a noticeable gap in Brazilian scientific production on the relationship between climate change and dengue, highlighting the need for further studies and investment in research. Originality/Value: This research underscores the relevance of climate change in vector-borne disease transmission, offering a bibliometric analysis that highlights aspects still underexplored in the scientific literature.

Eco-epidemiological aspects and risk factors associated with human Chagas disease in rural areas of the state of Piauí, Brazil

BackgroundPiauí is located in Northeastern Brazil, an endemic area for Chagas disease, with the Brazilian semiarid representing the second region in number of people infected by the parasite Trypanosoma cruzi. The state of Piauí is one of the most socially vulnerable territories with direct impact on the access to diagnosis and treatment of Chagas disease for the population living in rural communities. Triatoma brasiliensis is the vector species of greatest epidemiological importance in Northeastern Brazil. We investigated the triatomine fauna and risk factors associated to T. cruzi transmission in two municipalities, Pedro II and Oeiras, located in different mesoregions of Piauí.MethodsTwenty-three rural areas were selected for triatomines search and serological survey of the population. The analysis of triatomines consisted on identifying T. cruzi infection index by microscopy and kDNA-PCR followed by parasite genotyping through the use of multilocus PCR to characterize the discrete typing units (DTUS), and the identification of food sources using PCR directed to the 12S rRNA gene of vertebrates and sequencing.ResultsA total of 1,043 triatomines identified as T. brasiliensis, Triatoma pseudomaculata, Rhodnius nasutus, Rhodnius sp. and Panstrongylus lutzi were collected. The overall positivity for T. cruzi was 4.6% and 11.4% by microscopy and kDNA-PCR, respectively. The DTUs TcV (∼ 44%) and TcI (∼ 43%) were the most prevalent in either single or mixed infections. This is the first report of TcV and TcVI infections in vectors of Piauí. The most frequent blood source was Homo sapiens (46.5%), of which ∼ 42% individuals (28/67) were collected indoors and four of them (14.3%) tested positive for T. cruzi kDNA in Pedro II. Chicken (∼ 19%), domestic cat (∼ 17%) and others were also identified as feeding sources for triatomines. Serological survey revealed 2% seroprevalence. Variables as age over 60 years (p = 0.01), Black race (p = 0.002) and occupation as retired (p = 0.004) significantly influenced the seropositivity.ConclusionDespite the reduced seroprevalence of the population, the epidemiological scenario of Chagas disease in both municipalities highlights the risk of the re-emergence of domestic vector-borne transmission. Ensuring continued entomological surveillance and vector control programs and providing access to diagnosis and treatment for the susceptible population are still needed.

Climate Change and Emerging Infectious Diseases: Investigating the Influence on Transmission Dynamics of Vector-Borne Diseases

Background: Climate change significantly affects the transmission dynamics of vector-borne diseases by altering temperature and rainfall patterns, thus creating favorable conditions for vectors. Objective: This study aims to examine the impact of climate change on the incidence of vector-borne diseases, focusing on temperature and rainfall patterns in Dhaka. Method: A cross-sectional study was conducted from February to November 2023 at Shaheed Monsur Ali Medical College and Hospital, Uttara, Dhaka. A total of 125 patients diagnosed with dengue, malaria, and chikungunya were analyzed. Data on patient demographics, disease occurrence, and climate variables (temperature and rainfall) were collected. Regression analysis evaluated the relationship between climate factors and disease incidence. Results: Out of 125 patients, 69 (55%) had dengue, 31 (25%) had malaria, and 25 (20%) had chikungunya. Dengue cases peaked during the monsoon season (July to September), with a 35% increase compared to the dry season. A 1°C rise in temperature correlated with a 12% rise in disease incidence, while a 50 mm increase in rainfall resulted in a 15% increase in cases. Conclusion: The study confirms that rising temperatures and increased rainfall due to climate change are critical drivers of vector-borne disease transmission in Dhaka, necessitating targeted public health measures.

Bat-associated ticks as a potential link for vector-borne pathogen transmission between bats and other animals.

Potentially zoonotic pathogens have been previously detected in bat-associated ticks, but their role in disease transmission and their frequency of feeding on non-bat hosts is poorly known. We used molecular blood meal analysis to reveal feeding patterns of the bat-associated tick species Ixodes ariadnae, I. simplex, and I. vespertilionis collected from cave and mine walls in Central and Southeastern Europe. Vertebrate DNA, predominantly from bats, was detected in 43.5% of the samples (70 of 161 ticks) but in these ticks we also detected the DNA of non-chiropteran hosts, such as dog, Canis lupus familiaris, wild boar, Sus scrofa, and horse, Equus caballus, suggesting that bat-associated ticks may exhibit a much broader host range than previously thought, including domestic and wild mammals. Furthermore, we detected the zoonotic bacteria Neoehrlichia mikurensis in bat ticks for the first time, and other bacteria, such as Bartonella and Wolbachia. In the light of these findings, the role of bat ticks as disease vectors should be urgently re-evaluated in more diverse host systems, as they may contribute to pathogen transmission between bats and non-chiropteran hosts.

Features that matter: Evolutionary signatures can predict viral transmission routes.

Routes of virus transmission between hosts are key to understanding viral epidemiology. Different routes have large effects on viral ecology, and likelihood and rate of transmission; for example, respiratory and vector-borne viruses together encompass the majority of rapid outbreaks and high-consequence animal and plant epidemics. However, determining the specific transmission route(s) can take months to years, delaying mitigation efforts. Here, we identify the viral features and evolutionary signatures which are predictive of viral transmission routes and use them to predict potential routes for fully-sequenced viruses in silico and rapidly, for both viruses with no observed routes, as well as viruses with missing routes. This was achieved by compiling a dataset of 24,953 virus-host associations with 81 defined transmission routes, constructing a hierarchy of virus transmission encompassing those routes and 42 higher-order modes, and engineering 446 predictive features from three complementary perspectives. We integrated those data and features to train 98 independent ensembles of LightGBM classifiers. We found that all features contributed to the prediction for at least one of the routes and/or modes of transmission, demonstrating the utility of our broad multi-perspective approach. Our framework achieved ROC-AUC = 0.991, and F1-score = 0.855 across all included transmission routes and modes, and was able to achieve high levels of predictive performance for high-consequence respiratory (ROC-AUC = 0.990, and F1-score = 0.864) and vector-borne transmission (ROC-AUC = 0.997, and F1-score = 0.921). Our framework ranks the viral features in order of their contribution to prediction, per transmission route, and hence identifies the genomic evolutionary signatures associated with each route. Together with the more matured field of viral host-range prediction, our predictive framework could: provide early insights into the potential for, and pattern of viral spread; facilitate rapid response with appropriate measures; and significantly triage the time-consuming investigations to confirm the likely routes of transmission.

The Influence of Climate Change on Vector-Borne Diseases in a Wilderness Medicine Context.

The imminent climate crisis has been labeled as the biggest health threat humanity must deal with. Vector-borne disease distribution and transmission as well as the population at risk are influenced to a great degree by environmental and climactic factors affecting both the vectors themselves and the causative pathogens. Paired with an increase in worldwide travel, urbanization, and globalization, along with population displacements and migration, elucidating the effects of anthropogenic climate change on these illnesses is therefore of the essence to stave off potential negative sequelae. Outcomes on different vector-borne diseases will be diverse, but for many of them, these developments will result in a distribution shift or expansion with the possibility of (re-)introduction of vector and pathogen species in previously nonendemic areas. The consequence will be a growing likelihood for novel human, vector, and pathogen interactions with an increased risk for infection, morbidity, and mortality. Wilderness medicine professionals commonly work in close relationship to the natural environment and therefore will experience these alterations most strongly in their practice. Hence, this article attempts to bring awareness to the subject at hand in a wilderness medicine context, with a focus on malaria, the most burdensome of arthropod-borne diseases. For prevention of the potentially dire consequences on human health induced by climate change, concerted and intensified efforts to reduce the burning of fossil fuels and thus greenhouse gas emissions will be imperative on a global scale.

Tolfenpyrad Derivatives Exhibit Potent Francisella-Specific Antibacterial Activity without Toxicity to Mammalian Cells In Vitro.

Tularemia is a deadly disease caused by Francisella tularensis, an emerging intracellular bacterial pathogen that can be disseminated rapidly through aerosols and vector-borne transmission. Recent surveillance data demonstrate an increasing incidence in several countries. Although clinical isolates of Francisella strains are sensitive to currently used antibiotics, engineered or horizontal acquisition of antibiotic resistance is a constant threat to public health. Therefore, the identification of antibiotics that target previously undrugged pathways is required to safeguard human health. An environmental pesticide that is registered for use in multiple countries, tolfenpyrad, shows promising activity to block Francisella growth; however, it is not a suitable antimicrobial candidate for use in vivo due to potential toxicity in humans and other animals. In this study, we applied a structure-activity relationship approach to tolfenpyrad to generate compounds with improved antibacterial activity and reduced toxicity. Through screening of a library of derivatives, we identified analogs with improved therapeutic windows compared with tolfenpyrad. Although structural diversity exists among these analogs, they inhibit the growth of Francisella species but not other Gram-negative or Gram-positive species. These compounds block intramacrophage growth of F. novicida and pathogenesis in an in vivo arthropod model of infection. Although the biochemical activity of these drugs is unknown, they appear to target the same pathway as the parent molecule because F. novicida mutants that are resistant to tolfenpyrad are also resistant to its analogs. Taken together, these findings suggest that these tolfenpyrad-derived compounds comprise a new class of Francisella-targeted antimicrobials and merit further evaluation and development.

Climate Change and Vector-Borne Diseases: A Scoping Review on the Ecological and Public Health Impacts

Climate change is increasingly recognized as a significant driver of ecological and public health changes, particularly concerning vectorborne diseases. This scoping review aims to systematically map the current research on the impact of climate change on vector ecology and the subsequent effects on disease transmission dynamics. We conducted a comprehensive literature review across multiple databases to identify critical vectors, such as mosquitoes, ticks, and fleas. We examined how climate variables like temperature, precipitation, and humidity affect their populations, behaviors, and life cycles. Additionally, we explored the shifting geographic distributions of these vectors, investigating how climate change influences their spread and the emergence of diseases such as malaria, dengue, and Lyme disease in new regions. The review highlights the complex and multifaceted interactions between climate change and vector-borne diseases, emphasizing the necessity of understanding these relationships to inform effective public health strategies. Our findings indicate considerable variability in the impacts of climate change across different regions and vector species, underscoring the need for localized studies and tailored interventions. Moreover, significant research gaps were identified, particularly in predictive modeling, long-term surveillance, and the socio-economic impacts of vector-borne diseases exacerbated by climate change. We suggest directions for future research, including the development of integrated climate-health models and enhanced disease surveillance systems, to better anticipate and mitigate the effects of climate change on vector-borne disease transmission. This review underscores the urgency of addressing climate change as a critical component of global health initiatives and the importance of interdisciplinary approaches in tackling this complex issue. Bangladesh Journal of Medical Science Vol. 23 No. 04 October’24 Page : 915-933

Exploring Trypanosoma cruzi transmission dynamics in an acute Chagas disease outbreak using next-generation sequencing

BackgroundChagas disease (CD), caused by Trypanosoma cruzi, poses a major global public health challenge. Although vector-borne transmission is the primary mode of infection, oral transmission is increasingly concerning.MethodsThis study utilized long-amplicon-based sequencing (long-ABS), focusing on the 18S rRNA gene, to explore T. cruzi’s genetic diversity and transmission dynamics during an acute CD outbreak in Colombia, an area without domestic infestation.ResultsAnalyzing samples from five patients and five T. cruzi-positive marsupial samples, we identified coinfections between T. cruzi and Trypanosoma rangeli, mixed T. cruzi DTUs, suggesting possible links between human and marsupial T. cruzi infections. Coexistence of TcI, TcIV and T. rangeli suggests marsupial secretions as the possible source of T. cruzi transmission. Our investigation revealed diversity loss in DTUs TcIV and T. rangeli in humans after infection and in marsupial samples after culture.ConclusionThese findings provide significant insights into T. cruzi dynamics, crucial for implementing control and prevention strategies.Graphical abstract

Increased Virulence of Culicoides Midge Cell-Derived Bluetongue Virus in IFNAR Mice.

Bluetongue (BT) is a Culicoides midge-borne hemorrhagic disease affecting cervids and ruminant livestock species, resulting in significant economic losses from animal production and trade restrictions. Experimental animal infections using the α/β interferon receptor knockout IFNAR mouse model and susceptible target species are critical for understanding viral pathogenesis, virulence, and evaluating vaccines. However, conducting experimental vector-borne transmission studies with the vector itself are logistically difficult and experimentally problematic. Therefore, experimental infections are induced by hypodermic injection with virus typically derived from baby hamster kidney (BHK) cells. Unfortunately, for many U.S. BTV serotypes, it is difficult to replicate the severity of the disease seen in natural, midge-transmitted infections by injecting BHK-derived virus into target host animals. Using the IFNAR BTV murine model, we compared the virulence of traditional BHK cell-derived BTV-17 with C. sonorensis midge (W8) cell-derived BTV-17 to determine whether using cells of the transmission vector would provide an in vitro virulence aspect of vector-transmitted virus. At both low and high doses, mice inoculated with W8-BTV-17 had an earlier onset of viremia, earlier onset and peak of clinical signs, and significantly higher mortality compared to mice inoculated with BHK-BTV-17. Our results suggest using a Culicoides W8 cell-derived inoculum may provide an in vitro vector-enhanced infection to more closely represent disease levels seen in natural midge-transmitted infections while avoiding the logistical and experimental complexity of working with live midges.

Spatiotemporal Modeling of Aedes aegypti Risk: Enhancing Dengue Virus Control through Meteorological and Remote Sensing Data in French Guiana.

French Guiana lacks a dedicated model for developing an early warning system tailored to its entomological contexts. We employed a spatiotemporal modeling approach to predict the risk of Aedes aegypti larvae presence in local households in French Guiana. The model integrated field data on larvae, environmental data obtained from very high-spatial-resolution Pleiades imagery, and meteorological data collected from September 2011 to February 2013 in an urban area of French Guiana. The identified environmental and meteorological factors were used to generate dynamic maps with high spatial and temporal resolution. The study collected larval data from 261 different surveyed houses, with each house being surveyed between one and three times. Of the observations, 41% were positive for the presence of Aedes aegypti larvae. We modeled the Aedes larvae risk within a radius of 50 to 200 m around houses using six explanatory variables and extrapolated the findings to other urban municipalities during the 2020 dengue epidemic in French Guiana. This study highlights the potential of spatiotemporal modeling approaches to predict and monitor the evolution of vector-borne disease transmission risk, representing a major opportunity to monitor the evolution of vector risk and provide valuable information for public health authorities.

Preventing Vertical Transmission of Chagas Disease: An Emerging Public Health Issue in Perinatal Care.

Chagas [shah-guhs] disease, caused by the Trypanosoma cruzi parasite, presents a growing concern for health care providers overseeing perinatal care in the United States due to existing and expanding vector-borne transmission and population migration. This life-threatening disease can be transmitted vertically during pregnancy, although adequate testing and treatment can effectively reduce morbidity and mortality caused by Chagas disease. This article presents an overview of the disease burden in the United States and its implications for perinatal care providers including recommended testing and treatment practices and the information needed for patient education and shared decision-making regarding the management of care for individuals at risk of Chagas disease. Being informed about Chagas disease and its implications is needed for all individuals providing perinatal care and is especially critical for those overseeing the care of refugee and immigrant populations.

Grapevine Pinot gris virus spreads in infected vineyards: latent infections have no direct impact on grape production

BackgroundGrapevine Pinot gris virus (GPGV) infects grapevines worldwide and causes symptoms such as chlorotic mottling and deformations on leaves, stunted shoots and short panicles, or none of these symptoms if it appears as latent infection. So far, the consequences of GPGV infections for winegrowers are difficult to assess since important information such as plant performance at different GPGV infection levels and symptom expression are not fully clarified.MethodsIn order to investigate the course of GPGV spread, annual visual evaluations and ELISA tests were conducted over 3–4 consecutive years in four GPGV-infected vineyards in southern Germany: GEM, HEC, NIM, and REI. The program PATCHY was used to analyze spatial disease patterns. Sanger sequencing was used to determine virus isolates in vines at different GPGV infection levels, to test their respective influence on symptom expression. Yield and GrapeScan (FTIR) analyses were conducted to test the impact of different GPGV infection levels and isolates on fruit quantity and quality.ResultsGPGV infections significantly increased in all four vineyards (GEM 22–32%, HEC 50–99%, NIM 83–90%, REI 56–76%) with significant spreading patterns across and along rows. Specific symptom progression patterns were not observed. According to our results, the virus isolate has an influence on whether symptoms develop during a GPGV infection. While yield analyses revealed that yield losses only occur in symptomatic vines and range from 13 to 96% depending on the severity of symptoms, latent infections have no impact on grape production. No relevant effects of GPGV infections on must quality were observed.ConclusionsSecondary spread of GPGV was observed in all vineyards monitored, indicating vector-borne transmission that is likely to be accelerated by human viticultural management. GPGV should be further monitored to prevent the accumulation of detrimental symptomatic isolates. The results of this study can be used to assess the risk of GPGV to viticulture and should be considered when developing management strategies against the virus.

GIS-ODE: linking dynamic population models with GIS to predict pathogen vector abundance across a country under climate change scenarios.

Mechanistic mathematical models such as ordinary differential equations (ODEs) have a long history for their use in describing population dynamics and determining estimates of key parameters that summarize the potential growth or decline of a population over time. More recently, geographic information systems (GIS) have become important tools to provide a visual representation of statistically determined parameters and environmental features over space. Here, we combine these tools to form a 'GIS-ODE' approach to generate spatiotemporal maps predicting how projected changes in thermal climate may affect population densities and, uniquely, population dynamics of Ixodes ricinus, an important tick vector of several human pathogens. Assuming habitat and host densities are not greatly affected by climate warming, the GIS-ODE model predicted that, even under the lowest projected temperature increase, I. ricinus nymph densities could increase by 26-99% in Scotland, depending on the habitat and climate of the location. Our GIS-ODE model provides the vector-borne disease research community with a framework option to produce predictive, spatially explicit risk maps based on a mechanistic understanding of vector and vector-borne disease transmission dynamics.

Haemosporidian intensity and nestlings' life-history along an urban-to-rural gradient

Urban areas, i.e. dense housing and reduced green spaces, can significantly impact avian health, through altering land use and increasing biotic and abiotic stress. This study assessed the association of urbanization on haemosporidian infections, vectors, immune response, and body condition in Parus major nestlings, across four classes of urbanization along an urban-to-rural gradient in Vienna, Austria. Contrary to our expectations, vector abundance remained consistent across the gradient, while an increase in leukocyte count is positively associated with total parasite intensity. We found that nestlings in more urbanized areas exhibited higher parasite intensity and altered immune response, as evidenced by variations in the heterophil to lymphocyte ratio and leukocyte counts. Culicidae female vectors were associated with nestlings’ total parasites, scaled mass index, and industrial units. Nestlings in highly developed areas had higher infection rates than those in forests, suggesting increased exposure to infections. However, there was no clear relationship between total female vectors and total parasites. The level of urbanization negatively affected nestling body condition, with a decrease in fat deposits from forested to highly urbanized areas. Our findings highlight the complex interplay between urbanization, vector-borne parasite transmission, and host immune response, emphasizing the need for comprehensive urban planning to improve wildlife health and guarantee ecosystem functioning. Understanding how urbanization affects bird immunity and parasite infections is critical for adapting urban landscapes for wildlife health and ecosystem integrity.

The Effects of Climate Change on Maternal, Fetal and Neonatal Health: An in-Depth Review

The substantial elevation in atmospheric greenhouse gas levels is a consequence of human activities, resulting in a 1.1°C elevation in surface temperature as the worldwide average. The detrimental outcomes of this temperature rise encompass severe weather events, deterioration in food, water, and air quality, alongside an escalation in vector-borne infectious diseases and/or transmission risks. The mitigation and adaptation to climate change are pivotal factors for the survival of humanity in the midst of this existential crisis. Climate change exerts notable effects on maternal, fetal, and neonatal health, with women experiencing more adverse impacts compared to men. Pregnant women may face conditions such as hypertensive disorders like preeclampsia and eclampsia, gestational diabetes mellitus (GDM), variations in pregnancy duration, and mental health disorders. Fetal and newborn health can be affected, leading to results like preterm birth (<37 weeks of gestation), low birth weight (<2500 grams), congenital anomalies (including atrial septum issues), early membrane rupture (EMR), underdeveloped immune systems, intrauterine growth restriction (IUGR), and neonatal death. Effective interventions aimed at reducing heat-related risks should include health education on heat and heat increase risks for caregivers - other than parents - and clinicians responsible for childcare. Additionally, there is a need for improvements in cooling systems in healthcare facilities, fair enhancements in housing quality, and food systems. Focus should also be placed on nutrition and lifestyle counseling. Despite the growing attention to the influence of climate on human health, the risks associated with heat and other factors associated with climate for women, pregnant individuals, newborns, infants, and children are not sufficiently addressed. This review seeks to investigate the effects of climate change on maternal, fetal, and neonatal outcomes related to health based on existing literature.

Mosquito Vector Ecology in Swamp Ecosystems

This study investigates the ecological dynamics of mosquito vectors in the swamp ecosystems of Desa Kebun Raya, Kecamatan Kintap, Kabupaten Tanah Laut, Kalimantan Selatan. An entomological survey was conducted to assess species composition, abundance, and larval indices in relation to the unique swamp habitat. Four mosquito species were identified: Culex quinquefasciatus, Culex tritaeniorhynchus, Aedes aegypti, and Aedes albopictus. The dominance of Culex species, particularly C. quinquefasciatus, suggests a strong adaptation to the swamp environment. Larval indices indicated a high risk of vector-borne disease transmission, with a House Index (HI) of 35%, Container Index (CI) of 0.14%, and Breteau Index (BI) of 64%. The study highlights the complex interactions between swamp ecology, mosquito population dynamics, and potential disease transmission risks in this understudied region of Indonesia.

Exploring Climate-Disease Connections in Geopolitical Versus Ecological Regions: The Case of West Nile Virus in the United States.

Many infectious disease forecasting models in the United States (US) are built with data partitioned into geopolitical regions centered on human activity as opposed to regions defined by natural ecosystems; although useful for data collection and intervention, this has the potential to mask biological relationships between the environment and disease. We explored this concept by analyzing the correlations between climate and West Nile virus (WNV) case data aggregated to geopolitical and ecological regions. We compared correlations between minimum, maximum, and mean annual temperature; precipitation; and annual WNV neuroinvasive disease (WNND) case data from 2005 to 2019 when partitioned into (a) climate regions defined by the National Oceanic and Atmospheric Administration (NOAA) and (b) Level I ecoregions defined by the Environmental Protection Agency (EPA). We found that correlations between climate and WNND in NOAA climate regions and EPA ecoregions were often contradictory in both direction and magnitude, with EPA ecoregions more often supporting previously established biological hypotheses and environmental dynamics underlying vector-borne disease transmission. Using ecological regions to examine the relationships between climate and disease cases can enhance the predictive power of forecasts at various scales, motivating a conceptual shift in large-scale analyses from geopolitical frameworks to more ecologically meaningful regions.

Entomological investigation of triatomine fauna in rural communities in the state of Piauí, Brazilian semi-arid region

Objective: To describe the characteristics and distribution of triatomine fauna in rural communities of Simplício Mendes municipality, located in the state of Piauí, Brazilian semiarid region. Methods: This is a cross-sectional study and entomological survey conducted from 2022 to 2023. Insects were captured using active search method in all human dwellings, which were georeferenced, followed by characterized of species, sex, developmental stage, and identification of presence of infection by trypanosomatids. Results: All households (n=178) in 10 rural localities of the municipality were investigated, resulting in a household triatomine infestation rate of 14%. A total of 268 insects were collected, predominantly species from the Triatoma brasiliensis complex (n=190), immature developmental stage (n=172), and originating from peridomestic environments (n=250). The rate of triatomines with natural infection by Trypanosoma cruzi was 1.1%. Conclusion: The finding of infestation by species from the T. brasiliensis complex with higher concentration cohabiting extradomestic spaces, wide dispersion, and presence of natural infection by T. cruzi signals conditions for the maintenance of vector-borne transmission of Chagas disease in the municipality.