The prevalence of selected vector-borne diseases in dromedary camels (Camelus dromedarius) in the United Arab Emirates.

Vector-borne diseases (VBDs) affecting dromedary camels (Camelus dromedarius) have considerable importance in the United Arab Emirates (UAE) because of the consequences associated with production decline and economic losses. Our study aimed to determine the prevalence of selected VBDs in camels in the UAE and identify risk factors. This research is currently affected by the low number of epidemiological molecular surveys addressing this issue. Blood samples were obtained from 425 dromedary camels from different locations across the UAE. Whole genomic DNA was isolated, and PCR screening was done to detect piroplasmids (Babesia/Theileria spp.), Trypanosoma spp., and Anaplasmataceae spp. (Anaplasma, Ehrlichia, Neorickettsia and Wolbachia spp.). Amplicons were sequenced, and phylogenetic trees were constructed. Trypanosoma sequences were identified as T. brucei evansi, whereas Anaplasmataceae sequences were identified as A. platys-like. All camels were negative for Babesia/Theileria spp. (0%); however, 18 camels were positive for T. b. evansi (4%) and 52 were positive for A. platys-like (12%). Mixed infection with T. b. evansi and A. platys-like was found in one camel. Statistical analyses revealed that camels with a brown coat colour were significantly more prone to acquire the A. platys-like strain compared with those having a clearer coat. A similar finding was observed when comparing urban moving camels with desert indoor and urban indoor camels. Continuous disease surveillance is required to ensure and maintain the good health status of the camels in the UAE. Nonetheless, the risk of disease outbreak remains if the misuse of drugs continues.

Climate change: A driver of increasing vector-borne disease transmission in non-endemic areas.

In this Perspective, Shlomit Paz discusses the link between climate change and transmission of vector-borne diseases in non-endemic areas.

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.

Evaluating the long-term impact of COVID-19-associated public health interventions on zoonotic and vector-borne diseases in China: an interrupted time series analysis.

BACKGROUND: The long-term impact of COVID-19-associated public health interventions on zoonotic and vector-borne infectious diseases (ZVBs) remains uncertain. This study sought to examine the changes in ZVBs in China during the COVID-19 pandemic and predict their future trends. METHODS: Monthly incidents of seven ZVBs (Hemorrhagic fever with renal syndrome [HFRS], Rabies, Dengue fever [DF], Human brucellosis [HB], Leptospirosis, Malaria, and Schistosomiasis) were gathered from January 2004 to July 2023. An autoregressive fractionally integrated moving average (ARFIMA) by incorporating the COVID-19-associated public health intervention variables was developed to evaluate the long-term effectiveness of interventions and forecast ZVBs epidemics from August 2023 to December 2025. RESULTS: Over the study period, there were 1,599,647 ZVBs incidents. HFRS and rabies exhibited declining trends, HB showed an upward trajectory, while the others remained relatively stable. The ARFIMA, incorporating a pulse pattern, estimated the average monthly number of changes of - 83 (95% confidence interval [CI] - 353-189) cases, - 3 (95% CI - 33-29) cases, - 468 (95% CI - 1531-597) cases, 2191 (95% CI 1056-3326) cases, 7 (95% CI - 24-38) cases, - 84 (95% CI - 222-55) cases, and - 214 (95% CI - 1036-608) cases for HFRS, rabies, DF, HB, leptospirosis, malaria, and schistosomiasis, respectively, although these changes were not statistically significant besides HB. ARFIMA predicted a decrease in HB cases between August 2023 and December 2025, while indicating a relative plateau for the others. CONCLUSIONS: China's dynamic zero COVID-19 strategy may have exerted a lasting influence on HFRS, rabies, DF, malaria, and schistosomiasis, beyond immediate consequences, but not affect HB and leptospirosis. ARFIMA emerges as a potent tool for intervention analysis, providing valuable insights into the sustained effectiveness of interventions. Consequently, the application of ARFIMA contributes to informed decision-making, the design of effective interventions, and advancements across various fields.

Effects of cattle on vector-borne disease risk to humans: A systematic review.

Vector-borne pathogens (VBPs) causing vector-borne diseases (VBDs) can circulate among humans, domestic animals, and wildlife, with cattle in particular serving as an important source of exposure risk to humans. The close associations between humans and cattle can facilitate the transmission of numerous VBPs, impacting public health and economic security. Published studies demonstrate that cattle can influence human exposure risk positively, negatively, or have no effect. There is a critical need to synthesize the information in the scientific literature on this subject, in order to illuminate the various ecological mechanisms that can affect VBP exposure risk in humans. Therefore, the aim of this systematic review was to review the scientific literature, provide a synthesis of the possible effects of cattle on VBP risk to humans, and propose future directions for research. This study was performed according to the PRISMA 2020 extension guidelines for systematic review. After screening 470 peer-reviewed articles published between 1999-2019 using the databases Web of Science Core Collection, PubMed Central, CABI Global Health, and Google Scholar, and utilizing forward and backward search techniques, we identified 127 papers that met inclusion criteria. Results of the systematic review indicate that cattle can be beneficial or harmful to human health with respect to VBDs depending on vector and pathogen ecology and livestock management practices. Cattle can increase risk of exposure to infections spread by tsetse flies and ticks, followed by sandflies and mosquitoes, through a variety of mechanisms. However, cattle can have a protective effect when the vector prefers to feed on cattle instead of humans and when chemical control measures (e.g., acaricides/insecticides), semio-chemicals, and other integrated vector control measures are utilized in the community. We highlight that further research is needed to determine ways in which these mechanisms may be exploited to reduce VBD risk in humans.

A retrospective study of vector borne disease prevalence among anemic dogs in North Carolina.

BACKGROUND: Anemia is an important cause of morbidity and mortality in dogs. Further understanding of the prevalence of vector borne diseases (VBD) in anemic dogs is needed. OBJECTIVES: The objective of this retrospective study was to describe the rate of exposure to or infection with VBD among anemic dogs presented to a teaching hospital in North Carolina and to further characterize the anemia in dogs with VBD exposure. ANIMALS: A total of 597 anemic dogs that were concurrently tested for VBD were examined at a referral veterinary hospital between January 2012 and December 2018. METHODS: Retrospective descriptive study. Demographic, clinicopathologic, and VBD testing data were obtained from medical records. RESULTS: Of the 597 anemic dogs examined, 180 (30.15%; 95% CI: 26.49-34.01%) tested positive for one or more VBD. There was no difference in the severity of anemia or the proportion of dogs displaying a regenerative anemia between dogs testing positive and negative for VBD. CONCLUSIONS: A large proportion of anemic dogs from this region test positive for exposure to or infection with VBD. Our study supported the use of PCR and serology run in parallel to maximize the chance of detecting exposure to or infection with VBD compared to either serology or PCR alone. At this time, it is unknown whether infection with VBD contributed to the development of anemia in these patients. However, given the prevalence of VBD exposure in anemic dogs, testing for VBD in anemic patients from this region of the United States is warranted.

Threshold dynamics of an almost periodic vector-borne disease model.

Many infectious diseases cannot be transmitted from human to human directly, and the transmission needs to be done via a vector. It is well known that vectors' life cycles are highly dependent on their living environment. In order to investigate dynamics of vector-borne diseases under environment influence, we propose a vector-borne disease model with almost periodic coefficients. We derive the basic reproductive number [Formula: see text] for this model and establish a threshold type result on its global dynamics in terms of [Formula: see text]. As an illustrative example, we consider an almost periodic model of malaria transmission. Our numerical simulation results show that the basic reproductive number may be underestimated if almost periodic coefficients are replaced by their average values . Finally, we use our model to study the dengue fever transmission in Guangdong, China. The parameters are chosen to fit the reported data available for Guangdong. Numerical simulations indicate that the annual dengue fever case in Guangdong will increase steadily in the near future unless more effective control measures are implemented. Sensitivity analysis implies that the parameters with strong impact on the outcome are recovery rate, mosquito recruitment rate, mosquito mortality rate, baseline transmission rates between mosquito and human. This suggests that the effective control strategies may include intensive treatment, mosquito control, decreasing human contact number with mosquitoes (e.g., using bed nets and preventing mosquito bites), and environmental modification.

Basic reproduction ratio of a mosquito-borne disease in heterogeneous environment.

To explore the influence of spatial heterogeneity on mosquito-borne diseases, we formulate a reaction-diffusion model with general incidence rates. The basic reproduction ratio [Formula: see text] for this model is introduced and the threshold dynamics in terms of [Formula: see text] are obtained. In the case where the model is spatially homogeneous, the global asymptotic stability of the endemic equilibrium is proved when [Formula: see text]. Under appropriate conditions, we establish the asymptotic profiles of [Formula: see text] in the case of small or large diffusion rates, and investigate the monotonicity of [Formula: see text] with respect to the heterogeneous diffusion coefficients. Numerically, the proposed model is applied to study the dengue fever transmission. Via performing simulations on the impacts of certain factors on [Formula: see text] and disease dynamics, we find some novel and interesting phenomena which can provide valuable information for the targeted implementation of disease control measures.

[Climate change and vector-borne diseases. From knowledge to action]. / Cambio climático y enfermedades transmitidas por vectores. Convertir el conocimiento en acción.

Andalusia is particularly sensitive to climate change, not only because of extreme weather events, but also because of the impact on the population dynamics of vectors, pathogens, reservoirs and hosts, which has led to a change in the epidemiological patterns of vector-borne diseases. In order to achieve an integrated vector management for disease control, public action is necessary. This study describes the design of the initial phase of a strategy for knowledge translation about climate change and vector-borne diseases to the public, using transdisciplinary co-creation and the World Café participatory method with three discussion rounds to address strategies for three age groups (adults, adolescents and schoolchildren). The aim is to drive knowledge into action and for this purpose the underlying messages for action (strategic and instrumental) have been identified, as well as the formats of the knowledge products and the potential implementers of the strategies.

A general modeling framework for exploring the impact of individual concern and personal protection on vector-borne disease dynamics.

BACKGROUND: As climate variability and extreme weather events associated with climate change become more prevalent, public health authorities can expect to face an expanding spectrum of vector-borne diseases with increasing incidence and geographical spread. Common interventions include the use of larvicides and adulticides, as well as targeted communications to increase public awareness regarding the need for personal protective measures, such as mosquito repellant, protective clothing, and mosquito nets. Here, we propose a simplified compartmental model of mosquito-borne disease dynamics that incorporates the use of personal protection against mosquito bites influenced by two key individual-level behavioral drivers-concern for being bitten by mosquitos as a nuisance and concern for mosquito-borne disease transmission. METHODS: We propose a modified compartmental model that describes the dynamics of vector-borne disease spread in a naïve population while considering the public demand for community-level control and, importantly, the effects of personal-level protection on population-level outbreak dynamics. We consider scenarios at low, medium, and high levels of community-level vector control, and at each level, we consider combinations of low, medium, and high levels of motivation to use personal protection, namely concern for disease transmission and concern for being bitten in general. RESULTS: When there is very little community-level vector control, nearly the entire population is quickly infected, regardless of personal protection use. When vector control is at an intermediate level, both concerns that motivate the use of personal protection play an important role in reducing disease burden. When authorities have the capacity for high-level community vector control through pesticide use, the motivation to use personal protection to reduce disease transmission has little additional effect on the outbreak. CONCLUSIONS: While results show that personal-level protection alone is not enough to significantly impact an outbreak, personal protective measures can significantly reduce the severity of an outbreak in conjunction with community-level control. Furthermore, the model provides insight for targeting public health messaging to increase the use of personal protection based on concerns related to being bitten by mosquitos or vector-borne disease transmission.

Incidência de casos confirmados de dengue no Estado do Paraná Brasil nos anos de 2016 a 2021 / Incidence of confirmed dengue cases in the State of Paraná Brazil in the years of 2016 to 2021 / Incidencia de casos confirmados de dengue en el Estado de Paraná Brasil en los años 2016 a 2021

A dengue é uma doença dolorosa e debilitante transmitida por insetos da espécie Aedes aegypti. Ela é definida como uma doença viral que, nos últimos anos, se espalhou vertiginosamente por todas as regiões tropicais e subtropicais do planeta. Este estudo teve como objetivo identificar e discutir o número e a taxa de incidência de casos de dengue no estado do Paraná utilizando-se dos boletins emitidos por semana epidemiológica nos anos de 2016 a 2021, considerando a sazonalidade da doença. Também se objetivou debater a incidência por macrorregional, as possíveis causas de períodos epidêmicos e ações de combate vetorial para redução dos casos da patologia. Foram utilizados como fonte de informações o banco de dados da Dengue/SVS/SESA, por meio de informes técnicos, disponibilizados pelo portal online de Boletins da Dengue Paraná da Secretaria de Estado de Saúde do Paraná. Conclui-se que o ano epidemiológico de 2019/2020 foi o de maior incidência e os anos epidemiológicos 2016/2017 e 2017/2018 apresentaram os menores casos durante todo período analisado. Dessa forma, a vigilância epidemiológica é muito importante para avaliação espacial da distribuição de casos para execução de ações estratégicas para redução da infestação do vetor. As políticas públicas e a disponibilização de inseticidas para aplicação também são essenciais para o combate da Dengue.

Dengue is a painful and debilitating disease transmitted by insects of the Aedes aegypti species. It is defined as a viral disease that, in recent years, has spread vertiginously throughout the tropical and subtropical regions of the planet. This study aimed to identify and discuss the number and incidence rate of dengue cases in the state of Paraná using the bulletins issued by epidemiological week in the years 2016 to 2021, considering the seasonality of the disease. The aim was also to discuss the incidence per macro-region, the possible causes of epidemic periods, and vectorial combat actions to reduce the cases of the pathology. The Dengue/SVS/SESA database was used as a source of information, through technical reports, made available by the online portal of Dengue Paraná Bulletins of the Paraná State Health Department. It is concluded that the epidemiological year 2019/2020 was the one with the highest incidence and the epidemiological years 2016/2017 and 2017/2018 had the lowest cases during the entire period analyzed. Thus, epidemiological surveillance is very important for the spatial assessment of the distribution of cases to carry out strategic actions to reduce vector infestation. Public policies and the availability of insecticides for application are also essential to combat Dengue.

El dengue es una enfermedad dolorosa y debilitante transmitida por insectos de la especie Aedes aegypti. Se define como una enfermedad viral que, en los últimos años, se ha extendido vertiginosamente por las regiones tropicales y subtropicales del planeta. Este estudio tuvo como objetivo identificar y discutir el número y la tasa de incidencia de los casos de dengue en el estado de Paraná utilizando los boletines emitidos por la semana epidemiológica en los años 2016 a 2021, considerando la estacionalidad de la enfermedad. También se pretendía discutir la incidencia por macrorregiones, las posibles causas de los periodos epidémicos y las acciones de control de vectores para la reducción de los casos de la enfermedad. Se utilizó como fuente de información la base de datos de Dengue/SVS/SESA, por medio de informes técnicos, puestos a disposición por el portal online de Boletines de Dengue Paraná de la Secretaría de Salud del Estado de Paraná. Se concluye que el año epidemiológico 2019/2020 fue el de mayor incidencia y los años epidemiológicos 2016/2017 y 2017/2018 presentaron los menores casos durante todo el periodo analizado. Por lo tanto, la vigilancia epidemiológica es muy importante para la evaluación espacial de la distribución de los casos para la implementación de acciones estratégicas para reducir la infestación del vector. Las políticas públicas y la disponibilidad de insecticidas para su aplicación también son esenciales para combatir el dengue.

Vector-Borne diseases in Egypt: Present status and accelerating toward elimination.

Vector borne diseases (VBDs) remain one of the greatest dangers to global health. At least seven VBDs of public health concern are prevalent in Egypt, including schistosomiasis, fascioliasis, lymphatic filariasis, leishmaniasis, malaria, dengue, and Rift Valley fever. Although many of these diseases are preventable by using evidence-based protective measures, VBD expansion patterns over the past few decades pose a significant challenge for modern parasitology and tropical medicine. In their action plan, Egypt did not identify populations at risk of VBDs. Egypt intends to improve its regional and international communication to identify pathogens and infections and develop "One Health"- compliant preparedness and prevention strategies. However, cross-border collaborations are required for the control of VBDs. In this context, we provide a situational analysis and comprehensive review of the epidemiological data on Egypt's most prevalent VBDs based on an exhaustive search of the major electronic databases and literature from 1950 to 2019. We identified the gaps in Egypt's preparedness for vector-borne disease threats, including adaptation documents, surveillance and monitoring, environmental management, and preparations for the health system. There is a lack of implementation of an integrated vector management strategy that integrates chemical, environmental, and biological control as well as health education. This necessitates cross-sectoral coordination and community involvement to improve vector control activities and the use, storage, and disposal of pesticides.

Spatio-temporal distribution of vector borne diseases in Australia and Papua New Guinea vis-à-vis climatic factors.

BACKGROUND & OBJECTIVES: Weather and climate are directly linked to human health including the distribution and occurrence of vector-borne diseases which are of significant concern for public health. METHODS: In this review, studies on spatiotemporal distribution of dengue, Barmah Forest Virus (BFV) and Ross River Virus (RRV) in Australia and malaria in Papua New Guinea (PNG) under the influence of climate change and/ or human society conducted in the past two decades were analysed and summarised. Environmental factors such as temperature, rainfall, relative humidity and tides were the main contributors from climate. RESULTS: The Socio-Economic Indexes for Areas (SEIFA) index (a product from the Australian Bureau of Statistics that ranks areas in Australia according to relative socio-economic advantage and disadvantage) was important in evaluating contribution from human society. INTERPRETATION & CONCLUSION: For future studies, more emphasis on evaluation of impact of the El Niño-Southern Oscillation (ENSO) and human society on spatio-temporal distribution of vector borne diseases is recommended to highlight importance of the environmental factors in spreading mosquito-borne diseases in Australia and PNG.

Time-Scale Analysis and Parameter Fitting for Vector-Borne Diseases with Spatial Dynamics.

Vector-borne diseases are progressively spreading in a growing number of countries, and it has the potential to invade new areas and habitats. From the dynamical perspective, the spatial-temporal interaction of models that try to adjust to such events is rich and challenging. The first challenge is to address the dynamics of vectors (very fast and local) and the dynamics of humans (very heterogeneous and non-local). The objective of this work is to use the well-known Ross-Macdonald models, identifying different time scales, incorporating human spatial movements and estimate in a suitable way the parameters. We will concentrate on a practical example, a simplified space model, and apply it to dengue spread in the state of Rio de Janeiro, Brazil.

Comparing Vector-Borne Disease Surveillance and Response in Beijing and the Netherlands.

Background: Climate change, environmental change, and globalization affect the geographical distribution of vector-borne diseases. Temperate regions should be prepared for emerging diseases and learn from each other's experiences. Objectives: The vector-borne disease preparedness in two regions, Beijing and the Netherlands, were compared in order understand their similarities and differences leading to learning points on this complex topic. Methods: A comparative study was performed using interviews with vector-borne disease experts from Beijing and the Netherlands and supplemented by literature. Findings: In Beijing, syndromic surveillance is a priority for the identification of suspected vector-borne disease cases. In the Netherlands, the main surveillance emphasis is on laboratory confirmed vector-borne disease cases. Vector-surveillance at potential points of entry and other high-risk locations is performed according to the International Health Regulation (2005) in both settings. Beijing controls invasive and native mosquitos, which is not the case in the Netherlands. In Beijing, vector surveillance is performed to measure mosquito density around hospitals, this is not observed in the Dutch setting. Health risks posed by ticks are a priority in urban areas in the Netherlands, and the public is educated in self-protection. In contrast, ticks seem to occur less often in Beijing's urban areas. Conclusions: The vector-borne disease context framework allowed us to compare the vector-borne disease preparedness between Beijing and the Netherlands, despite differences in vector-borne disease challenges. We can learn valuable lessons concerning surveillance and early detection of emerging vector-borne diseases when comparing the preparedness between different regions.

Comparison of time series and mechanistic models of vector-borne diseases.

Vector-borne disease models are widely used to understand the dynamics involved in virus transmission. The simplest version of the mechanistic SEIR-SEI model is the most widely used representation of the dynamics involved in vector-borne diseases. Modifications to the basic model can improve the complex dynamics' acuracy. This work evaluates the capability of different models to represent the dynamics involved in dengue virus transmission. The models include a vector life stage representation, a re-susceptibility factor, and environmental variables in a mechanistic form. Furthermore, Autoregressive Integrated Moving Average methodologies (ARIMA method) were also used for comparison. The inclusion of environmental variables and vector life cycle improves the model's accuracy for mechanistic models, but the modification's complexity can restrict its applicability. Data-driven techniques were shown to be less accurate than all the mechanistic-based models (based on all criteria adopted).

Efficacy of a spatial repellent for control of Aedes-borne virus transmission: A cluster-randomized trial in Iquitos, Peru.

Over half the world's population is at risk for viruses transmitted by Aedes mosquitoes, such as dengue and Zika. The primary vector, Aedes aegypti, thrives in urban environments. Despite decades of effort, cases and geographic range of Aedes-borne viruses (ABVs) continue to expand. Rigorously proven vector control interventions that measure protective efficacy against ABV diseases are limited to Wolbachia in a single trial in Indonesia and do not include any chemical intervention. Spatial repellents, a new option for efficient deployment, are designed to decrease human exposure to ABVs by releasing active ingredients into the air that disrupt mosquito-human contact. A parallel, cluster-randomized controlled trial was conducted in Iquitos, Peru, to quantify the impact of a transfluthrin-based spatial repellent on human ABV infection. From 2,907 households across 26 clusters (13 per arm), 1,578 participants were assessed for seroconversion (primary endpoint) by survival analysis. Incidence of acute disease was calculated among 16,683 participants (secondary endpoint). Adult mosquito collections were conducted to compare Ae. aegypti abundance, blood-fed rate, and parity status through mixed-effect difference-in-difference analyses. The spatial repellent significantly reduced ABV infection by 34.1% (one-sided 95% CI lower limit, 6.9%; one-sided P value = 0.0236, z = 1.98). Aedes aegypti abundance and blood-fed rates were significantly reduced by 28.6 (95% CI 24.1%, ∞); z = -9.11) and 12.4% (95% CI 4.2%, ∞); z = -2.43), respectively. Our trial provides conclusive statistical evidence from an appropriately powered, preplanned cluster-randomized controlled clinical trial of the impact of a chemical intervention, in this case a spatial repellent, to reduce the risk of ABV transmission compared to a placebo.

Vector-borne pathogens in dogs from areas where leishmaniosis is endemic.

Many vector-borne pathogens (VBPs), including Ehrlichia canis and Dirofilaria immitis, may infect simultaneously dogs in areas where Leishmania infantum is endemic, especially in the tropics, where highly abundant arthropod vectors thrive. The aim of this study was to compare the frequency of simultaneous VBPs infection in Leishmania-positive and Leishmania-negative dogs. Animals enrolled in this study were divided in two groups (G1 and G2), G1 being comprised of L. infantum-infected dogs (n = 58) and the G2 of L. infantum-negative dogs (n = 58). Blood samples were screened using a qualitative ELISA test (SNAP® 4Dx® Plus, IDEXX Laboratory, Westbrook, Maine, USA) for detection of antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and antigens of Dirofilaria immitis. Overall, 89.7% (52/58) of dogs from G1 were positive for at least one VBP, whereas 50.0% (29/58) of dogs from G2 dogs were positive as well. The highest positivity was to E. canis (67.2%; 78/116), followed by D. immitis (12.9%; 15/116), and A. platys (6.0%; 7/116). None of the animals scored positive for B. burgdorferi s.l.. There was a statistically significant difference for the simultaneous positivity to E. canis plus D. immitis between groups. Furthermore, 43.1% (25/58) of dogs from G1 were infested by ectoparasites (ticks, fleas, or both), compared to 20.6% (12/58) of dogs from G2. In conclusion, Leishmania-infected dogs were more co-infected with other VBPs than Leishmania-negative animals. Therefore, it is pivotal to increase the awareness of veterinarian and dog owners about the importance of testing Leishmania-infected dogs for other VBPs, as this may directly affect treatment decisions and management.

Implicit versus explicit vector management strategies in models for vector-borne disease epidemiology.

Throughout the vector-borne disease modeling literature, there exist two general frameworks for incorporating vector management strategies (e.g. area-wide adulticide spraying and larval source reduction campaigns) into vector population models, namely, the "implicit" and "explicit" control frameworks. The more simplistic "implicit" framework facilitates derivation of mathematically rigorous results on disease suppression and optimal control, but the biological connection of these results to real-world "explicit" control actions that could guide specific management actions is vague at best. Here, we formally define a biological and mathematical relationship between implicit and explicit control, and we provide mathematical expressions relating the strength of implicit control to management-relevant properties of explicit control for four common intervention strategies. These expressions allow the optimal control and basic reproduction number analyses typically utilized in implicit control modeling to be interpreted directly in terms of real-world actions and real-world monetary costs. Our methods reveal that only certain sub-classes of explicit control protocols are able to be represented as implicit controls, and that implicit control is a meaningful approximation of explicit control only when resonance-like synergistic effects between multiple explicit controls have negligible effects on population reduction. When non-negligible synergy exists, implicit control results, despite their mathematical tidiness, fail to provide accurate predictions regarding vector control and disease spread. Collectively, these elements build an effective bridge between analytically interesting and mathematically tractable implicit control and the challenging, action-oriented explicit control.

Effects of land use and weather on the presence and abundance of mosquito-borne disease vectors in a urban and agricultural landscape in Eastern Ontario, Canada.

Weather and land use can significantly impact mosquito abundance and presence, and by consequence, mosquito-borne disease (MBD) dynamics. Knowledge of vector ecology and mosquito species response to these drivers will help us better predict risk from MBD. In this study, we evaluated and compared the independent and combined effects of weather and land use on mosquito species occurrence and abundance in Eastern Ontario, Canada. Data on occurrence and abundance (245,591 individuals) of 30 mosquito species were obtained from mosquito capture at 85 field sites in 2017 and 2018. Environmental variables were extracted from weather and land use datasets in a 1-km buffer around trapping sites. The relative importance of weather and land use on mosquito abundance (for common species) or occurrence (for all species) was evaluated using multivariate hierarchical statistical models. Models incorporating both weather and land use performed better than models that include weather only for approximately half of species (59% for occurrence model and 50% for abundance model). Mosquito occurrence was mainly associated with temperature whereas abundance was associated with precipitation and temperature combined. Land use was more often associated with abundance than occurrence. For most species, occurrence and abundance were positively associated with forest cover but for some there was a negative association. Occurrence and abundance of some species (47% for occurrence model and 88% for abundance model) were positively associated with wetlands, but negatively associated with urban (Culiseta melanura and Anopheles walkeri) and agriculture (An. quadrimaculatus, Cs. minnesotae and An. walkeri) environments. This study provides predictive relationships between weather, land use and mosquito occurrence and abundance for a wide range of species including those that are currently uncommon, yet known as arboviruses vectors. Elucidation of these relationships has the potential to contribute to better prediction of MBD risk, and thus more efficiently targeted prevention and control measures.