scholarly journals Vector dynamics influence spatially imperfect genetic interventions against disease

2020 ◽  
Author(s):  
Mete K Yuksel ◽  
Christopher H Remien ◽  
Bandita Karki ◽  
James J Bull ◽  
Stephen M Krone
Keyword(s):  
Spatial Structure ◽  
Mathematical Models ◽  
Human Movement ◽  
Structured Populations ◽  
Vector Borne Diseases ◽  
Spatially Structured Populations ◽  
Parasite Reproduction ◽  
Vector Borne ◽  
Genetic Interventions ◽  
Imperfect Coverage

Abstract Background and objectives Genetic engineering and similar technologies offer promising new approaches to controlling human diseases by blocking transmission from vectors. However, in spatially structured populations, imperfect coverage of the vector will leave pockets in which the parasite may persist. Movement by humans may disrupt this local persistence and facilitate eradication when these pockets are small, spreading parasite reproduction outside unprotected areas and into areas that block its reproduction. Here we consider the sensitivity of this process to biological details: do simple generalities emerge that may facilitate interventions? Methodology We develop formal mathematical models of this process similar to standard Ross-Macdonald models, but (i) specifying spatial structure of two patches, with vector transmission blocked in one patch but not in the other, (ii) allowing temporary human movement (travel instead of migration), and (iii) considering two different modes of mosquito biting. Results We find that there is no invariant effect of disrupting spatial structure with travel. For both biting models, travel out of the unprotected patch has different consequences than travel by visitors into the patch, but the effects are reversed between the two biting models. Conclusions and implications Overall, the effect of human travel on the maintenance of vector-borne diseases in structured habitats must be considered in light of the actual biology of mosquito abundances, biting dynamics, and human movement patterns. Lay summary Genetic interventions against pathogens transmitted by insect vectors are promising methods of controlling infectious diseases. These interventions may be imperfect, leaving pockets where the parasite persists. How will human movement between protected and unprotected areas affect persistence? Mathematical models developed here show that the answer is ecology-dependent, depending on vector biting behavior.

scholarly journals Vector dynamics influence spatially imperfect genetic interventions against disease

2020 ◽  
Author(s):  
Mete K Yuksel ◽  
Christopher H Remien ◽  
Bandita Karki ◽  
James J Bull ◽  
Stephen M Krone
Keyword(s):  
Spatial Structure ◽  
Mathematical Models ◽  
Human Movement ◽  
Structured Populations ◽  
Vector Borne Diseases ◽  
Spatially Structured Populations ◽  
Parasite Reproduction ◽  
Vector Borne ◽  
Genetic Interventions ◽  
Imperfect Coverage

AbstractBackground and objectivesGenetic engineering and similar technologies offer promising new approaches to controlling human diseases by blocking transmission from vectors. However, in spatially structured populations, imperfect coverage of the vector will leave pockets in which the parasite can persist. Yet movement by humans may disrupt this local persistence and facilitate eradication when these pockets are small, essentially distributing parasite reproduction out of unprotected areas and into areas that block its reproduction.MethodologyWe develop formal mathematical models of this process similar to standard Ross-Macdonald models, but (i) specifying spatial structure of two patches, with transmission blocked in one patch but not in the other, (ii) allowing temporary human movement (travel instead of migration), and (iii) considering two different modes of mosquito biting.ResultsWe find that there is no invariant effect of disrupting spatial structure with travel. For both biting models, travel out of the unprotected patch has different consequences than travel by visitors into the patch, but the effects are reversed between the two biting models.Conclusions and implicationsOverall, the effect of human travel on the maintenance of vector-borne diseases in structured habitats must be considered in light of the actual biology of mosquito abundances and biting dynamics.Lay summaryGenetic interventions against pathogens transmitted by insect vectors are promising methods of controlling infectious diseases. These interventions may be imperfect, leaving pockets where the parasite persists. How will human movement between protected and unprotected areas affect persistence? Mathematical models developed here show that the answer is ecology-dependent, depending on vector biting behavior.

The Scientific Basis for the Prevention of Zooanthroponoze Vector-Borne Diseases Spread by Parasitic Arthropods of the Center of the East European Plain

2020 ◽  
Vol 14 (1) ◽  
pp. 81-88
Author(s):  
Fedor I. Vasilevich ◽  
Anna M. Nikanorova
Keyword(s):  
Mathematical Models ◽  
Culex Pipiens ◽  
Preventive Measures ◽  
Mosquito Species ◽  
Natural Habitat ◽  
Piperonyl Butoxide ◽  
East European Plain ◽  
Vector Borne Diseases ◽  
Vector Borne ◽  
Kaluga Region

The purpose of the research is development of preventive measures against zooanthroponoze vector-borne diseases spread by parasitic arthropods in the Kaluga Region. Materials and methods. The subject of the research was Ixodidae, mosquitoes, and small mammals inhabiting the Kaluga Region. The census of parasitic arthropods was carried out on the territory of all districts of the Kaluga Region and the city of Kaluga. Open natural habitat and human settlements were investigated. Weather conditions from 2013 to 2018 were also taken into account. For the purposes of the study, we used standard methods for capturing and counting arthropods and mouse-like rodents. In order to obtain mathematical models of small mammal populations, a full factorial experiment was conducted using the collected statistical data. In-process testing of the drug based on s-fenvalerate and piperonyl butoxide were carried out under the conditions of the agricultural collective farm “Niva” of the Kozelsky District, the Kaluga Region, and LLC “Angus Center of Genetics” of the Babyninsky District, the Kaluga Region. Results and discussion. In the Kaluga Region, two species of ixodic ticks are found, namely, Ixodes ricinus and Dermacentor reticulatus, which have two activity peaks. Mosquito may have 3-4 generations in a year in the Kaluga region. The most common mosquito species in the Kaluga Region are Aedes communis, Ae. (Och.) togoi and Ae. (Och.) diantaeus, Culex pipiens Culex Linnaeus, 1758 (Diptera, Culicidae) (Culex pipiens): Cx. pipiens f. pipiens L. (non-autogenic form) and Cx. p. f. molestus Fors. (autogenic form), which interbreed, and reproductively isolated in the Region. The developed mathematical models make it possible to quantify the risks of outbreaks of zooanthroponoze vector-borne diseases without the cost of field research, and allow for rational, timely and effective preventive measures. Medications based on s-fenvalerate and piperonyl butoxide and based on cyfluthrin showed high insecto-acaricidal efficacy and safety.

scholarly journals Vector-borne disease risk indexes in spatially structured populations

2018 ◽  
Vol 12 (2) ◽  
pp. e0006234 ◽  
Author(s):  
Jorge Velázquez-Castro ◽  
Andrés Anzo-Hernández ◽  
Beatriz Bonilla-Capilla ◽  
Moisés Soto-Bajo ◽  
Andrés Fraguela-Collar
Keyword(s):  
Disease Risk ◽  
Structured Populations ◽  
Vector Borne Disease ◽  
Spatially Structured Populations ◽  
Vector Borne

How to model the impact of climate change on vector-borne diseases?

2021 ◽  
pp. 26-31
Author(s):  
Cyril Caminade
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Mathematical Models ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Risk ◽  
Vector Borne Diseases ◽  
Impact Of Climate Change ◽  
Vector Borne ◽  
The Impact

Abstract This expert opinion provides an overview of mathematical models that have been used to assess the impact of climate change on ticks and tick-borne diseases, ways forward in terms of improving models for the recent context and broad guidelines for conducting future climate change risk assessment.

scholarly journals Dynamics of Zika virus outbreaks: an overview of mathematical modeling approaches

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4526 ◽  
Author(s):  
Anuwat Wiratsudakul ◽  
Parinya Suparit ◽  
Charin Modchang
Keyword(s):  
Public Health ◽  
Mathematical Models ◽  
Real World ◽  
Zika Virus ◽  
Real World Data ◽  
World Data ◽  
Vector Borne Diseases ◽  
Complex Models ◽  
Vector Borne ◽  
Simple Models

BackgroundThe Zika virus was first discovered in 1947. It was neglected until a major outbreak occurred on Yap Island, Micronesia, in 2007. Teratogenic effects resulting in microcephaly in newborn infants is the greatest public health threat. In 2016, the Zika virus epidemic was declared as a Public Health Emergency of International Concern (PHEIC). Consequently, mathematical models were constructed to explicitly elucidate related transmission dynamics.Survey MethodologyIn this review article, two steps of journal article searching were performed. First, we attempted to identify mathematical models previously applied to the study of vector-borne diseases using the search terms “dynamics,” “mathematical model,” “modeling,” and “vector-borne” together with the names of vector-borne diseases including chikungunya, dengue, malaria, West Nile, and Zika. Then the identified types of model were further investigated. Second, we narrowed down our survey to focus on only Zika virus research. The terms we searched for were “compartmental,” “spatial,” “metapopulation,” “network,” “individual-based,” “agent-based” AND “Zika.” All relevant studies were included regardless of the year of publication. We have collected research articles that were published before August 2017 based on our search criteria. In this publication survey, we explored the Google Scholar and PubMed databases.ResultsWe found five basic model architectures previously applied to vector-borne virus studies, particularly in Zika virus simulations. These include compartmental, spatial, metapopulation, network, and individual-based models. We found that Zika models carried out for early epidemics were mostly fit into compartmental structures and were less complicated compared to the more recent ones. Simple models are still commonly used for the timely assessment of epidemics. Nevertheless, due to the availability of large-scale real-world data and computational power, recently there has been growing interest in more complex modeling frameworks.DiscussionMathematical models are employed to explore and predict how an infectious disease spreads in the real world, evaluate the disease importation risk, and assess the effectiveness of intervention strategies. As the trends in modeling of infectious diseases have been shifting towards data-driven approaches, simple and complex models should be exploited differently. Simple models can be produced in a timely fashion to provide an estimation of the possible impacts. In contrast, complex models integrating real-world data require more time to develop but are far more realistic. The preparation of complicated modeling frameworks prior to the outbreaks is recommended, including the case of future Zika epidemic preparation.

scholarly journals Antisocial rewarding in structured populations

2016 ◽  
Author(s):  
Miguel dos Santos ◽  
Jorge Peña
Keyword(s):  
Spatial Structure ◽  
Social Interactions ◽  
Structured Populations ◽  
Theoretic Model ◽  
Mixed Strategies ◽  
Weak Selection ◽  
The Public ◽  
Spatially Structured Populations ◽  
Game Theoretic ◽  
Game Theoretic Model

ABSTRACTCooperation in collective action dilemmas usually breaks down in the absence of additional incentive mechanisms. This tragedy can be escaped if cooperators have the possibility to invest in reward funds that are shared exclusively among cooperators(prosocial rewarding). Yet, the presence of defectors who do not contribute to the public good but do reward themselves(antisocial rewarding) deters cooperation in the absence of additional countermeasures. A recent simulation study suggests that spatial structure is sufficient to prevent antisocial rewarding from deterring cooperation. Here we reinvestigate this issue assuming mixed strategies and weak selection on a game-theoretic model of social interactions, which we also validate using individual-based simulations. We show that increasing reward funds facilitates the maintenance of prosocial rewarding but prevents its evolution from rare, and that spatial structure can sometimes select against the evolution of prosocial rewarding. Our results suggest that, even in spatially structured populations, additional mechanisms are required to prevent antisocial rewarding from deterring cooperation in public goods dilemmas.

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