Disease spread through animal movements: a static and temporal network analysis of pig trade in Germany

Background: Animal trade plays an important role for the spread of infectious diseases in livestock populations. As a case study, we consider pig trade in Germany, where trade actors (agricultural premises) form a complex network. The central question is how infectious diseases can potentially spread within the system of trade contacts. We address this question by analyzing the underlying network of animal movements. Methodology/Findings: The considered pig trade dataset spans several years and is analyzed with respect to its potential to spread infectious diseases. Focusing on measurements of network-topological properties, we avoid the usage of external parameters, since these properties are independent of specific pathogens. They are on the contrary of great importance for understanding any general spreading process on this particular network. We analyze the system using different network models, which include varying amounts of information: (i) static network, (ii) network as a time series of uncorrelated snapshots, (iii) temporal network, where causality is explicitly taken into account. Findings: Our approach provides a general framework for a topological-temporal characterization of livestock trade networks. We find that a static network view captures many relevant aspects of the trade system, and premises can be classified into two clearly defined risk classes. Moreover, our results allow for an efficient allocation strategy for intervention measures using centrality measures. Data on trade volume does barely alter the results and is therefore of secondary importance. Although a static network description yields useful results, the temporal resolution of data plays an outstanding role for an in-depth understanding of spreading processes. This applies in particular for an accurate calculation of the maximum outbreak size.Comment: main text 33 pages, 17 figures, supporting information 7 pages, 7 figure

Influence of a high fat diet during adolescence on the reinforcing effects of cocaine and alcohol

RESUMEN La adolescencia es un período de especial vulnerabilidad en el desarrollo del ser humano, en el que se dan grandes cambios a nivel estructural y funcional (Spear, 2000; Chambers et al., 2003). En esta etapa de gran vulnerabilidad, los jóvenes muestran trastornos de la alimentación, consumo de sustancias, búsqueda de sensaciones y conductas de riesgo (Bava and Tapert, 2010). Actualmente, el consumo excesivo de comida especialmente rica en azúcares y grasas, se ha convertido en un serio problema para nuestra sociedad, habiéndose producido un incremento en las tasas de obesidad a nivel mundial que afecta particularmente a la población adolescente. La alimentación está regulada tanto por mecanismos homeostáticos como hedónicos. Un malfuncionamiento de cualquiera de estos sistemas puede provocar una alteración en la alimentación y producir obesidad (Kenny et al., 2011). El sistema de refuerzo, constituido esencialmente por el sistema dopaminérgico mesocorticolímbico, regula la motivación para buscar o consumir estímulos reforzantes como las drogas o la comida altamente palatable. Por lo tanto, el consumo de drogas o la alimentación por razones hedónicas activan las mismas vías del refuerzo. Inicialmente nuestro organismo se desarrolló en un contexto caracterizado por la escasez nutricional y conseguir alimentos era el principal objetivo a alcanzar en el día a día. Ya que nuestro cuerpo procesa los alimentos de forma rápida, mostramos una preferencia innata por las comidas con alto contenido calórico y energético. Este tipo de alimentos, al igual que la cocaína o el alcohol, producen liberación de dopamina en el sistema de recompensa cerebral. Hoy en día, en la sociedad de la abundancia y la variedad de alimentos, comemos no sólo por hambre, sino también por placer (Gold, 2011). Por lo tanto, comer por placer afecta a los mecanismos neurales relacionados con el refuerzo y promueve el mantenimiento de esta conducta (ver revisión Avena et al., 2008; Volkow et al., 2013). En resumen, tanto los reforzadores naturales como las drogas estimulan el circuito cerebral de recompensa, produciendo placer y euforia. El estado nutricional es un importante factor modulador en el desarrollo de la adicción, y algunos estudios han mostrado similitudes psicológicas y biológicas entre la ingesta de comida rápida y la adicción a las drogas, (Garber and Lustig, 2011; Avena et al., 2012). Por ejemplo, tanto la adicción a las drogas como la obesidad pueden ser definidas como trastornos en los que el valor de determinado refuerzo (droga o comida) está anormalmente incrementado en relación y a expensas de otros refuerzos. La adicción a drogas y los atracones de comida se caracterizan por una pérdida de control sobre la conducta consumatoria, la escalada, la dependencia y el ansia por consumir (craving), mostrando ambos trastornos una elevada comorbilidad (Swanson et al., 2011). Numerosos estudios han puesto de manifiesto que el consumo de drogas durante la adolescencia incrementa la probabilidad de desarrollar dependencia y problemas relacionados con estas sustancias en la edad adulta (Arteaga et al., 2010; Merline et al., 2004). Se ha propuesto igualmente una teoría de puerta de entrada también para la comida y el abuso de sustancias (Degenhardt y cols., 2008). Esta teoría postula que la ingesta compulsiva de comida puede facilitar el desarrollo de otros comportamientos desadaptativos, como es el consumo de drogas. Por el momento, los estudios preclínicos indican que el atracón de comida rica en azúcar provoca a una sensibilización conductual a la anfetamina (Avena y Hoebel, 2003) y aumenta la autoadministración de alcohol (Avena y cols., 2004). Se han realizado estudios utilizando comida rica en azúcar, sin embargo, los estudios con comida rica en grasa son escasos. Hasta la fecha todavía no se han evaluado las consecuencias de realizar atracones de grasa durante la adolescencia sobre el consumo de drogas como la cocaína y el alcohol. Tampoco conocemos los efectos de suspender el consumo de una dieta alta en grasas, sobre los efectos gratificantes de la cocaína o el alcohol. Así pues, el objetivo de la presente tesis doctoral ha sido evaluar cómo una dieta alta en grasa consumida durante la adolescencia, puede modificar los efectos reforzantes de la cocaína y el alcohol. Estudiamos dos tipos diferentes de consumo de la dieta alta en grasa, el acceso continuado a la dieta rica en grasa (los animales consumen la dieta durante todo el periodo de tiempo correspondiente, sin limitar su acceso) y el atracón, que es un acceso limitado e intermitente. Este último patrón se ha demostrado que induce un consumo de grasa en forma de atracones (Puhl y cols., 2011; Bocarsly y cols., 2011). En el protocolo de administración intermitente los ratones tienen acceso a la dieta rica en grasa solo durante 2 horas los lunes, miércoles y viernes con un acceso ilimitado a la dieta estándar. Como metodología principal para evaluar la respuesta a la cocaína y el alcohol utilizamos los paradigmas de Condicionamiento de la Preferencia de Lugar y el procedimiento de Autoadministración operante. El Condicionamiento de la Preferencia de lugar es el paradigma más utilizado para medir el efecto de las claves ambientadas asociadas con los efectos reforzantes de las drogas (Aguilar et al., 2013). Por otro lado, el modelo de autoadministración operante evalúa directamente la motivación del animal por conseguir la sustancia. Ambos modelos proporcionan una evaluación completa de los efectos reforzantes de las drogas, ya que nos permiten medir tanto las claves individuales como las externas. También hemos estudiado los efectos metabólicos que estos tipos de dieta grasa producían en los niveles plasmáticos de leptina, grelina y corticosterona. Igualmente, hemos estudiado mediante la reacción en cadena de la polimerasa (PCR) en tiempo real, la expresión de genes pertenecientes a los sistemas dopaminérgico, cannabinoide y opioide, debido a su implicación tanto en el refuerzo inducido por las drogas como por la comida. En cuanto a los resultados obtenidos, en el primer estudio hemos observado que, aunque no hay cambios en ninguna de las conductas estudiadas mientras se mantiene el consumo de grasa, el cese de esta dieta produce un incremento en el nivel de ansiedad, aumenta la respuesta aguda a la cocaína y produce condicionamiento de la preferencia de lugar con dosis subumbrales de cocaína. Todo esto se acompaña por cambios a nivel de expresión del gen para el receptor opioide mu, el cannabinoide CB1 y GHSR. Por otro lado, observamos el poder de la dieta rica en grasa como refuerzo alternativo, ya que cuando la administramos tras condicionar a los animales con una dosis efectiva, éstos tardan menos en extinguir la preferencia y no presentan reinstauración con dosis con las que el grupo control sí reinstaura la preferencia de lugar. En el segundo estudio hemos evaluado el efecto de realizar atracones de una dieta rica en grasa y hemos observado que provocan un aumento en la sensibilidad a dosis subumbrales de cocaína en el condicionamiento de la preferencia de lugar y se autoadministran más cocaína que el grupo con dieta estándar. Por otro lado, observamos también cambios en la expresión de los genes responsables de los receptores opioide mu, cannabinoide CB1 y de la grelina GHSR. En el tercer estudio realizamos el mismo procedimiento que en el estudio anterior, pero con el fin de evaluar si este tipo de administración de dieta rica en grasa también incrementaba la sensibilidad al alcohol. De nuevo encontramos que los animales que realizan atracones son más sensibles a dosis subumbrales de alcohol y se autoadministran más que el grupo con dieta estándar. Además, presentan cambios a nivel de expresión de genes tras la autoadministración, diferentes a los obtenidos con la simple administración de la grasa en estudios anteriores. En el cuarto estudio evaluamos si estos efectos sobre la ingesta de alcohol tenían un efecto a largo plazo, incluso habiendo cesado el consumo de grasa. Observamos cómo los animales que realizaron atracones durante la adolescencia y llevaban 15 días sin acceso a la grasa seguían presentando un incremento en la autoadministración de alcohol, pero ya no eran más sensibles a los efectos reforzantes de una dosis subumbral de alcohol en el condicionamiento de la preferencia de lugar. En el quinto estudio evaluamos el papel que tiene un estrés crónico, como es el aislamiento, en la modulación que produce la dieta rica en grasa en atracón sobre los efectos reforzantes de la cocaína. Observamos resultados opuestos a los obtenidos con animales agrupados, ya que los animales aislados con una dieta estándar fueron más sensibles a dosis subumbrales de cocaína que los que realizaron atracones de dieta rica en grasa. Además, los grupos que desarrollaron la preferencia (aislados dieta estándar y agrupados dieta atracón grasa) también presentaron niveles incrementados de leptina. En el sexto y último estudio trazamos un perfil conductual con todos los grupos que hemos utilizado en la presente tesis doctoral, observando que los animales que realizan atracones de grasa presentan pocas alteraciones conductuales. Únicamente exhiben un incremento en la actividad locomotora y conductas agresivas en la interacción social con un oponente. Sí que observamos déficits a nivel de aprendizaje espacial con los animales que comen comida rica en grasa de forma continuada y además de un comportamiento agresivo. En ambos tipos de dieta, el cese del consumo produce un incremento en el nivel de ansiedad. Los resultados obtenidos nos indican el consumo de una dieta alta en grasa de forma continuada produce efectos muy diferentes a los producidos por el consumo intermitente en atracón. Mientras que el consumo en forma de atracón no produce grandes efectos metabólicos, incrementa la sensibilidad a los efectos reforzantes del alcohol y la cocaína. Sin embargo, el consumo de grasa de forma continuada produce grandes cambios metabólicos, como hiperleptinemia y aumento de peso, pero no afecta la respuesta a la cocaína. Sin embargo, tras el cese en el consumo continuado de una dieta alta en grasa, aparece un incremento en la respuesta a los efectos condicionados reforzantes de la cocaína, confirmando así que el sistema de refuerzo ha quedado sensibilizado tras el consumo de grasa. Ambos tipos de dieta alta en grasa produce cambios en la expresión génica de los receptores opioide mu, cannabinoide CB1 y del receptor de grelina GHSR, indicando que ambos patrones de consumo de grasa modifican de forma diferente la función del sistema de refuerzo cerebral, produciendo consecuencias a largo plazo, incluso cuando la comida rica en grasa ya no está disponible. Nuestro trabajo demuestra que los hábitos nutricionales no solo producen alteraciones metabólicas en nuestro organismo o modifican nuestro peso corporal. También modifican nuestro SNC y alteran la forma en que respondemos a las drogas de abuso. Una de las principales aportaciones de este trabajo es la demostración de que la dieta grasa consumida de forma continuada, que induce grandes cambios metabólicos y obesidad, así como alteraciones conductuales, no parece modular la respuesta a las drogas hasta que esta deja de consumirse, momento en el que observamos una respuesta incrementada. Sin embargo, los atracones de grasa, que no alteran metabólicamente al sujeto, ni modifican su peso corporal o su conducta, sí que incrementan la respuesta a drogas como la cocaína o el etanol, incluso cuando ya ha dejado de consumirse. Por lo tanto, esperamos que los artículos que componen la presente Tesis Doctoral ayuden a incrementar el conocimiento y la conciencia sobre la importancia de los hábitos nutricionales en el abordaje de un problema multifactorial como es la adicción a las drogas.  ABSTRACT Adolescence is a highly vulnerable developmental period in which numerous structural and functional maturational changes occur (Spear, 2000; Chambers et al., 2003). In this early stage of vulnerability, adolescents exhibit eating disorders, substance abuse, novelty-seeking and risk-taking behaviors (Bava and Tapert, 2010). Regarding these environmental hazards, the rise in obesity rates worldwide has encouraged extensive research to improve understanding of this problem, in which the excessive intake of food, especially sugar-rich and high-fat food has become a serious problem for society. As we know, addiction is a chronic and multifactorial relapsing disorder resulting from an interaction of biological and environmental aspects, characterized by a loss of control in the use of the substance and relapse (Koob and Volkow, 2010). Developmental factors are important components of vulnerability, with strong evidence supporting that exposure to drugs of abuse during adolescence leads to a significantly higher likelihood of drug dependence and drug-related problems in adulthood. Feeding is regulated by homeostatic and hedonic mechanisms. Abnormalities in these functions can cause several feeding alterations and produce obesity (Kenny et al., 2011). The reward system, which is essentially constituted by the dopamine mesocorticolimbic system, regulates motivation to seek and take rewarding stimuli, such as drugs or highly palatable food. Therefore, drug abuse or hedonic eating activate the same reward pathways. Our body was initially developed in a context characterized by nutritional deficiencies and getting food was the daily main objective to achieve. It processes foods quickly and we have innate preference for high energy meals, especially those high in fat and sugar, because in a situation of scarcity those would be the energy stores that would help us to survive. This type of food, like drugs of abuse, produces a dopamine release in the brain reward system, which explains its pleasurable effects. Nowadays, there is such abundance and variety of food, that this survival-oriented evolutionary adaptation has lost its sense, since we eat not only for hunger, but also for pleasure (Gold, 2011). Thus, hedonic eating affects neural mechanisms connected with reward and maintains this behavior (For reviews: Avena et al., 2008; Volkow et al., 2013). In summary, both natural reinforcers and drugs stimulate the brain reward circuit, producing pleasure and euphoria. The nutritional status is an important factor in the development of addiction, since some studies indicate psychological and biological similarities between fast food intake and addiction to drugs, sharing common reward mechanisms (Garber and Lustig, 2011; Avena et al., 2012). For example, both drug addiction and obesity can be defined as disorders in which the value of the type of reinforcement (drug or food, respectively) is abnormally increased in relationship to other reinforcements (Avena et al., 2012; Volkow et al., 2013). Drug addiction and binge eating are characterized by a loss of control over consummatory behaviors, exhibiting escalation, dependence and craving when the reward is not available, and both present a high comorbidity (Swanson et al., 2011). Several studies report that drug use during adolescence often predicts an increased likelihood of continued use into adulthood (Arteaga et al., 2010; Merline et al., 2004). Based on these relationships, a Theory of Gateway has also been proposed for eating disorders and substance abuse (Degenhardt et al., 2008), in which it is postulated that eating disorders, such as binge eating, can lead to the development of another desadaptive behavior, such as drug abuse. At the moment, preclinical studies indicate, for example, that intake of certain types of sugar leads to a sensitization to amphetamine (Avena and Hoebel, 2003) and to an increase in alcohol self-administration (Avena et al., 2004). Studies with sugar are abundant, unlike studies with high-fat food and drug vulnerability. For example, there are no studies reporting the effects of bingeing on fat during adolescence and vulnerability to drug abuse, like cocaine or alcohol, nor are there studies examining the effects of interrupting fat consumption on the subsequent vulnerability to drugs like cocaine or alcohol. Thus, the objective of the present work was to evaluate how a high-fat diet exposure during adolescence modulates the reinforcing effects of cocaine and alcohol. We studied two different types of fat diet consumption: continuous access (animals have ad libitum access to high-fat food without a limit) and the intermittent and limited access. The latter has been shown to induce a binge eating pattern (Puhl and cols., 2011; Bocarsly et al., 2011), and our protocol is based on that used by Corwin et al. (1998). Here, mice had access to the high-fat diet only for 2 hours every Monday, Wednesday and Friday, with ad libitum access to the standard diet. The main methodology employed to assess the vulnerability to cocaine and alcohol rewarding effects was the Conditioned Place Preference paradigm and the operant Self-Administration procedure. The conditioned place preference is the most commonly used test to evaluate the environmental cues conditioned to the rewarding effects of the drug (Aguilar et al., 2013), while the self-administration procedure evaluates directly the animals’ motivation to obtain the substance of abuse. Both models provide a complete scenario to evaluate vulnerability to drug abuse, since they allow us to measure both the external and the individual cues. We have also studied some metabolic effects on circulating leptin, ghrelin and corticosterone levels and examined changes in gene expression with real time polymerase chain reaction (rt-PCR) related to dopaminergic, opioid and endocannabinoid systems, because of their involvement in the rewarding properties of drugs and food. Regarding our results, in the first study we observed no effects on the behavioral response to drugs while fat is available. However, following fat discontinuation, mice exhibited increased anxiety, augmented locomotor response to cocaine, and developed preference for subthreshold doses of cocaine. In addition, there were changes in MOr, CB1 and GHSR gene expression. On the other hand, we observed how high-fat diets act as an alternative reinforcer, as its administration after conditioned place preference reduces the number of sessions required to extinguish the preference and decreased sensitivity to drug priming-induced reinstatement. In the second study, we observed that animals that binged on fat were more sensitive to the reinforcing effects of a subthreshold dose of cocaine in the conditioned place preference and enhanced self-administration. We also observed changes in MOr, CB1 and GHSR gene expression. In the third study, we employed the same procedure as in the former study, but with the aim of evaluating if the increased sensitivity also arises with alcohol. Animals in the high-fat binge group presented more sensitivity to the rewarding effects of subthreshold doses of ethanol and greater ethanol consumption with a higher motivation to obtain the drug. In addition, they presented changes in gene expression after the self-administration procedure which are different from those found with the fat administration alone. In the fourth study, we evaluated if these effects of bingeing on fat and alcohol intake would have a long term consequences, even when fat consumption is interrupted. Our results showed how after 15 days from the last binge session, animals still presented a greater ethanol consumption, but they were not sensitive to subthreshold doses in the conditioned place preference anymore. The fifth study aimed to evaluate the role of chronic stress, such as isolation, on the modulatory effects of fat on the rewarding properties of cocaine. We observed opposite effects as those found in grouped animals, as isolated mice with a standard diet access were more sensitive to subthreshold doses of cocaine than those fed with a fat binge eating pattern. In addition, the groups that developed preference (isolated with standard diet and grouped with high-fat binge) were those who presented increased circulating leptin levels. In the sixth and last study, we drew a behavioral profile with the groups used in the present doctoral thesis, and found a few alterations in animals that binge on fat, such as hyperlocomotion and aggressive behaviors. On the other hand, we observed marked spatial learning deficits in animals eating fat continuously as well as increased attack behaviors with conspecifics. In both diet patterns, discontinuation of fat led to an increase in anxiety levels. Our results show that bingeing on fat is quite different from eating fat continuously. While the former does not produce great metabolic effects, it produces significant changes in the sensitivity to drugs such as alcohol and cocaine. On the other hand, continuously eating fat produces big metabolic changes like hyperleptinemia and increased bodyweight and but has no effect regarding vulnerability to drug use. However, when access to fat is interrupted (withdrawal period), the increased response to the rewarding effects of drugs arises, confirming that the reward system has become sensitized. Both fat consumption patterns produce several changes in gene expression of mu opioid receptor, of cannabinoid receptor CB1 and of ghrelin receptor GHSR, indicating that both patterns of fat consumption changed the reward system function in different manners, having long-lasting effects, even when fat is no longer available. Our work shows that the nutritional habits not only produce metabolic alterations in our organism or modify our body weight, they also modify our CNS and change the way w

Assessing anti-rabies baiting – what happens on the ground?

BACKGROUND: Rabies is one of the most hazardous zoonoses in the world. Oral mass vaccination has developed into the most effective management method to control fox rabies. The future need to control the disease in large countries (i.e. Eastern Europe and the Americas) forces cost-benefit discussions. The 'Increase bait density' option refers to the usual management assumption that more baits per km(2 )could compensate for high fox abundance and override the imperfect supply of bait pieces to the individual fox. METHODS: We use a spatial simulation, which combines explicitly fox space use (tessellation polygons) and aeroplane flight lines (straight lines). The number of baits actually falling into each polygon is measured. The manager's strategic options are converted into changes of the resulting bait distribution on the ground. The comparison enables the rating of the options with respect to the management aim (i.e. accessibility of baits). RESULTS: Above 5% (approx. 10%) of all fox groups without any bait (at most 5 baits) relate to the baiting strategy applied in the field (1 km spaced parallel flight lines, 20 baits per km(2 )distributed) under habitat conditions comparable to middle and western Europe (fox group home-range 1 km(2), 2.5 adults; reference strategy). Increasing the bait density on the same flight-line pattern neither reduces the number of under-baited fox group home-ranges, nor improves the management outcome and hence wastes resources. However, reducing the flight line distance provides a more even bait distribution and thus compensates for missed fox groups or extra high fox density. The reference strategy's bait density can be reduced when accounting for the missed fox groups. The management result with the proper strategy is likely the same but with reduced costs. CONCLUSION: There is no overall optimal strategy for the bait distribution in large areas. For major parts of the landscape, the reference strategy will be more competitive. In situations where set backs are attributed to non-homogeneous bait accessibility the distribution scheme has to be refined zone-based (i.e. increase of the flight line length per unit area). However, increase in bait density above the reference strategy appears inappropriate at least for non-urban abundance conditions of the red fox

Kinetics of maternal immunity against rabies in fox cubs (Vulpes vulpes)

BACKGROUND: In previous experiments, it was demonstrated that maternal antibodies (maAb) against rabies in foxes (Vulpes vulpes) were transferred from the vixen to her offspring. However, data was lacking from cubs during the first three weeks post partum. Therefore, this complementary study was initiated. METHODS: Blood samples (n = 281) were collected from 64 cubs (3 to 43 days old) whelped by 19 rabies-immune captive-bred vixens. Sera was collected up to six times from each cub. The samples were analysed by a fluorescence focus inhibition technique (RFFIT), and antibody titres (nAb) were expressed in IU/ml. The obtained data was pooled with previous data sets. Subsequently, a total of 499 serum samples from 249 cubs whelped by 54 rabies-immune vixens were fitted to a non-linear regression model. RESULTS: The disappearance rate of maAb was independent of the vixens' nAb-titre. The maAb-titre of the cubs decreased exponentially with age and the half-life of the maAb was estimated to be 9.34 days. However, maAb of offspring whelped by vixens with high nAb-titres can be detected for longer by RFFIT than that of offspring whelped by vixens with relatively low nAb-titres. At a mean critical age of about 23 days post partum, maAb could no longer be distinguished from unspecific reactions in RFFIT depending on the amount of maAb transferred by the mother. CONCLUSIONS: The amount of maAb cubs receive is directly proportional to the titre of the vixen and decreases exponentially with age below detectable levels in seroneutralisation tests at a relatively early age

Solar Science with the Atacama Large Millimeter/Submillimeter Array — A New View of Our Sun

The Atacama Large Millimeter/submillimeter Array (ALMA) is a new powerful tool for observing the Sun at high spatial, temporal, and spectral resolution. These capabilities can address a broad range of fundamental scientific questions in solar physics. The radiation observed by ALMA originates mostly from the chromosphere—a complex and dynamic region between the photosphere and corona, which plays a crucial role in the transport of energy and matter and, ultimately, the heating of the outer layers of the solar atmosphere. Based on first solar test observations, strategies for regular solar campaigns are currently being developed. State-of-the-art numerical simulations of the solar atmosphere and modeling of instrumental effects can help constrain and optimize future observing modes for ALMA. Here we present a short technical description of ALMA and an overview of past efforts and future possibilities for solar observations at submillimeter and millimeter wavelengths. In addition, selected numerical simulations and observations at other wavelengths demonstrate ALMA’s scientific potential for studying the Sun for a large range of science cases

Emergency vaccination of rabies under limited resources – combating or containing?

BACKGROUND: Rabies is the most important viral zoonosis from a global perspective. Worldwide efforts to combat the disease by oral vaccination of reservoirs have managed to eradicate wildlife rabies in large areas of central Europe and North-America. Thus, repeated vaccination has been discontinued recently on a geographical scale. However, as rabies has not yet been eradicated globally, a serious risk of re-introduction remains. What is the best spatial design for an emergency vaccination program – particularly if resources are limited? Either, we treat a circular area around the detected case and run the risk of infected hosts leaving the limited control area, because a sufficient immunisation level has not yet been built up. Or, initially concentrate the SAME resources in order to establish a protective ring which is more distant from the infected local area, and which then holds out against the challenge of the approaching epidemic. METHODS: We developed a simulation model to contrast the two strategies for emergency vaccination. The spatial-explicit model is based on fox group home-ranges, which facilitates the simulation of rabies spread to larger areas relevant to management. We used individual-based fox groups to follow up the effects of vaccination in a detailed manner. Thus, regionally – bait distribution orientates itself to standard schemes of oral immunisation programs and locally – baits are assigned to individual foxes. RESULTS: Surprisingly, putting the controlled area ring-like around the outbreak does not outperform the circular area of the same size centred on the outbreak. Only during the very first baitings, does the ring area result in fewer breakouts. But then as rabies is eliminated within the circle area, the respective ring area fails, due to the non-controlled inner part. We attempt to take advantage of the initially fewer breakouts beyond the ring when applying a mixed strategy. Therefore, after a certain number of baitings, the area under control was increased for both strategies towards the same larger circular area. The circle-circle strategy still outperforms the ring-circle strategy and analysis of the spatial-temporal disease spread reveals why: improving control efficacy by means of a mixed strategy is impossible in the field, due to the build-up time of population immunity. CONCLUSION: For practical emergency management of a new outbreak of rabies, the ring-like application of oral vaccination is not a favourable strategy at all. Even if initial resources are substantially low and there is a serious risk of rabies cases outside the limited control area, our results suggest circular application instead of ring vaccination

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2

Spatio-temporal analysis of fox rabies cases in Germany 2005-2006

Aiming to achieve new insights into rabies dynamics, this paper is the first to investigate fox rabies in Germany from a space-time pattern perspective. Based on a locally restricted dataset covering a fourteen month period, our findings indicate a strongly aggregated spatiotemporal point pattern resulting from an inhomogeneous stochastic process. In contrast to spatial or temporal approaches or cellular automata, our analysis focuses on the disease dynamics in time and space in a continuous time domain. Our findings confirm existing theories regarding fox rabies control highlighting the potential risk of urban areas and the need for effective rabies vaccination