Novel methods for the control of phlebotomine sand flies (Diptera: Psychodidae)

In arid and semi-arid parts of the Old World, Phlebotomus paptasi is a significant biting pest of man and is the primary vector of Leishmania major, the causative agent of zoonotic cutaneous leishmaniasis (ZCL). Phlebotomus papatasi exhibits a close association with the burrowing rodents that serve as the reservoirs of L. major. Rodent burrows are considered to be the primary habitat of immature P. papatasi in ZCL foci, and sand fly larvae have been observed feeding on rodent feces. In laboratory studies, five insecticides (diflubenzuron, novaluron, methoprene, pyriproxyfen, or ivermectin) were incorporated into the diet of Syrian hamsters and evaluated as feed-throughs to control immature sand flies. Feces of hamsters fed a diet containing approximately 10 mg/kg diflubenzuron, novaluron, or pyriproxyfen, or 20 mg/kg ivermectin killed 100% of sand fly larvae that consumed these feces. Feces of hamsters fed a diet containing up to 978.8 mg/kg methoprene caused significant, but not complete, mortality of sand fly larvae. Feces of novaluron-treated hamsters also were held under simulated field conditions for up to 30 d, and all larvae that consumed these feces died before pupation; a significant reduction in treated larval survival relative to control was observed when the feces were aged for up to 150 d. Novaluron also was shown to be effective as a feed-though larvicide when novaluron-treated food made up only a portion of the diet of hamsters. Ivermectin also was evaluated as a systemic insecticide; ivermectin treatment of hamsters was 100% effective against bloodfeeding sand flies for up to 7 d after hamsters were withdrawn from ivermectin-treated diets. In the final study, proof of concept was established for a novel biomarker system using a feed-through fluorescent dye. The value of this method is that it can mark rodents and their feces to establish the consumption of treated-baits, mark adult female sand flies that feed rodents for the duration of persistence of the dye in rodents, and mark adult male and female sand flies that had fed on feces of bait-fed rodents as larvae

Main outcomes of the Phebus FPT1 uncertainty and sensitivity analysis in the EU-MUSA project

The Management and Uncertainties of Severe Accidents (MUSA) project was funded in HORIZON 2020 and is coordinated by CIEMAT (Spain). The project aims at consolidating a harmonized approach for the analysis of uncertainties and sensitivities associated with Severe Accidents (SAs) analysis, focusing on source term figures of merit. The Application of Uncertainty Quantification (UQ) Methods against Integral Experiments (AUQMIE – Work Package 4 (WP4)), led by ENEA (Italy), was devoted to apply and test UQ methodologies adopting the internationally recognized PHEBUS FPT1 test. FPT1 was chosen to test UQ methodologies because, even though it is a simplified SA scenario, it was representative of the in-vessel phase of a severe accident initiated by a break in the cold leg of a PWR primary circuit. WP4 served as a platform to identify and discuss the issues encountered in the application of UQ methodol ogies to SA analyses (e.g. discuss the UQ methodology, perform the coupling between the SA codes and the UQ tools, define the results post-processing methods, etc.). The purpose of this paper is to describe the MUSA PHEBUS FPT1 uncertainty application exercise with the related specifications and the methodologies used by the partners to perform the UQ exercise. The main outcomes and lessons learned of the analysis are: scripting was in general needed for the SA code and uncertainty tool coupling and to have more flexibility; particular attention should be devoted to the proper choice of the input uncertain parameters; outlier values of figures of merit should be carefully analyzed; the computational time is a key element to perform UQ in SA; the large number of uncertain input parameters may complicate the interpretation of correlation or sensitivity analysis; there is the need for a statistically solid handling of failed calculations

First outcomes from the PHEBUS FPT1 uncertainty application done in the EU MUSA project

The Management and Uncertainties of Severe Accidents (MUSA) project, founded in HORIZON 2020 and coordinated by CIEMAT (Spain), aims to consolidate a harmonized approach for the analysis of uncertainties and sensitivities associated with Severe Accidents (SAs) by focusing on Source Term (ST) Figure of Merits (FOM). In this framework, among the 7 MUSA WPs the Application of Uncertainty Quantification (UQ) Methods against Integral Experiments (AUQMIE – Work Package 4 (WP4)), led by ENEA (Italy), looked at applying and testing UQ methodologies, against the internationally recognized PHEBUS FPT1 test. Considering that FPT1 is a simplified but representative SA scenario, the main target of the WP4 is to train project partners to perform UQ for SA analyses. WP4 is also a collaborative platform for highlighting and discussing results and issues arising from the application of UQ methodologies, already used for design basis accidents, and in MUSA for SA analyses. As a consequence, WP4 application creates the technical background useful for the full plant and spent fuel pool applications planned along the MUSA project, and it also gives a first contribution for MUSA best practices and lessons learned. 16 partners from different world regions are involved in the WP4 activities. The purpose of this paper is to describe the MUSA PHEBUS FPT1 uncertainty application exercise, the methodologies used by the partners to perform the UQ exercise, and the first insights coming out from the calculation phase

Emerging Themes and Future Directions of Multi-Sector Nexus Research and Implementation

Water, energy, and food are all essential components of human societies. Collectively, their respective resource systems are interconnected in what is called the “nexus”. There is growing consensus that a holistic understanding of the interdependencies and trade-offs between these sectors and other related systems is critical to solving many of the global challenges they present. While nexus research has grown exponentially since 2011, there is no unified, overarching approach, and the implementation of concepts remains hampered by the lack of clear case studies. Here, we present the results of a collaborative thought exercise involving 75 scientists and summarize them into 10 key recommendations covering: the most critical nexus issues of today, emerging themes, and where future efforts should be directed. We conclude that a nexus community of practice to promote open communication among researchers, to maintain and share standardized datasets, and to develop applied case studies will facilitate transparent comparisons of models and encourage the adoption of nexus approaches in practice

Emerging Themes and Future Directions of Multi-Sector Nexus Research and Implementation

Water, energy, and food are all essential components of human societies. Collectively, their respective resource systems are interconnected in what is called the “nexus”. There is growing consensus that a holistic understanding of the interdependencies and trade-offs between these sectors and other related systems is critical to solving many of the global challenges they present. While nexus research has grown exponentially since 2011, there is no unified, overarching approach, and the implementation of concepts remains hampered by the lack of clear case studies. Here, we present the results of a collaborative thought exercise involving 75 scientists and summarize them into 10 key recommendations covering: the most critical nexus issues of today, emerging themes, and where future efforts should be directed. We conclude that a nexus community of practice to promote open communication among researchers, to maintain and share standardized datasets, and to develop applied case studies will facilitate transparent comparisons of models and encourage the adoption of nexus approaches in practice

Laboratory evaluation of oral treatment of rodents with systemic insecticides for control of bloodfeeding sand flies (Diptera: Psychodidae)

The purpose of this study was to evaluate the efficacy of oral treatment of rodents with diets containing the systemic insecticides ivermectin, abamectin, imidacloprid, or spinosad, to control bloodfeeding sand flies. We found that diets containing concentrations higher than 10 mg/kg abamectin were not palatable to rodents, and that a diet containing 10 mg/kg abamectin (a palatable concentration) did not cause 100% mortality of bloodfeeding sand flies. Treatment of rodents with imidacloprid was effective for less than 3 days post-treatment. Treatment of rodents with diets containing 20 mg/kg ivermectin or 5000 mg/kg spinosad caused 100% mortality of bloodfeeding sand flies for at least 1 week. The efficacy of ivermectin and spinosad also were not reduced when combined with the fluorescent tracer dye rhodamine B in a single diet. We also did not observe significant benefits by increasing the feeding period of the rodents from 3 to 6 or 9 days. We conclude that ivermectin and spinosad are effective as rodent systemic insecticides against bloodfeeding sand flies, and suggest that weekly treatment of wild rodent reservoirs of Leishmania major with bait containing one of these systemic insecticides could be a useful tool as part of a sand fly control program. © Copyright 2012, Mary Ann Liebert, Inc. 2012

Ecological and Control Techniques for Sand Flies (Diptera: Psychodidae) Associated with Rodent Reservoirs of Leishmaniasis

BACKGROUND: Leishmaniasis remains a global health problem because of the substantial holes that remain in our understanding of sand fly ecology and the failure of traditional vector control methods. The specific larval food source is unknown for all but a few sand fly species, and this is particularly true for the vectors of Leishmania parasites. We provide methods and materials that could be used to understand, and ultimately break, the transmission cycle of zoonotic cutaneous leishmaniasis. METHODS AND FINDINGS: We demonstrated in laboratory studies that analysis of the stable carbon and nitrogen isotopes found naturally in plant and animal tissues was highly effective for linking adult sand flies with their larval diet, without having to locate or capture the sand fly larvae themselves. In a field trial, we also demonstrated using this technique that half of captured adult sand flies had fed as larvae on rodent feces. Through the identification of rodent feces as a sand fly larval habitat, we now know that rodent baits containing insecticides that have been shown in previous studies to pass into the rodents' feces and kill sand fly larvae also could play a future role in sand fly control. In a second study we showed that rubidium incorporated into rodent baits could be used to demonstrate the level of bloodfeeding by sand flies on baited rodents, and that the elimination of sand flies that feed on rodents can be achieved using baits containing an insecticide that circulates in the blood of baited rodents. CONCLUSIONS: Combined, the techniques described could help to identify larval food sources of other important vectors of the protozoa that cause visceral or dermal leishmaniasis. Unveiling aspects of the life cycles of sand flies that could be targeted with insecticides would guide future sand fly control programs for prevention of leishmaniasis

Health challenges of rangers—a planetary health workforce

Rangers safeguard the balance between humans and nature by protecting and managing biodiversity and natural resources. The challenging working conditions that rangers face make them vulnerable to wildlife attacks and exposure to zoonotic and vector-borne diseases. Despite all of these work-related challenges and threats to their health, a vast majority of rangers lack access to adequate medical treatment facilities. This research has used data from the one of the largest and most comprehensive surveys of rangers across multiple countries, collected as part of the Global Ranger Perception Survey, to examine the relationship between the precarious working conditions of rangers and their health outcomes. By comparing data from the 2020 World Malaria Report, our study highlights the severe malaria burden carried by rangers around the world. Malaria prevalence in rangers working in Central Africa, East Africa, and South America was estimated to be four times higher than in the general population. The results of this study are valuable because they show that rangers are a vulnerable, high-risk population of professionals and their working conditions are highly associated with their respective health outcomes. The research also makes it imperative that improving working conditions is essential for maintaining a professional ranger workforce that protects the planet’s natural areas and biodiversity