scholarly journals Predicting spread and effective control measures for African swine fever– should we blame the boars?

2019 ◽  
Author(s):  
Rachel A. Taylor ◽  
Tomasz Podgórski ◽  
Robin R. L. Simons ◽  
Sophie Ip ◽  
Paul Gale ◽  
...  
Keyword(s):  
At Risk ◽  
Wild Boar ◽  
Control Strategies ◽  
Control Measure ◽  
African Swine Fever ◽  
Control Measures ◽  
Effective Control ◽  
Risk Of Infection ◽  
Long Distance ◽  
Baltic Countries

SummaryAfrican swine fever (ASF) has been causing multiple outbreaks in Russia, Poland and the Baltic countries in recent years and is currently spreading westwards throughout Europe and eastwards into China, with cases occurring in wild boar and domestic pigs. Curtailing further spread of ASF requires full understanding of the transmission pathways of the disease. Wild boars have been implicated as a potential reservoir for the disease and one of the main modes of transmission within Europe. We developed a spatially explicit model to estimate the risk of infection with ASF in boar and pigs due to the natural movement of wild boar that is applicable across the whole of Europe. We demonstrate the model by using it to predict the probability that early cases of ASF in Poland were caused by wild boar dispersion. The risk of infection in 2015 is computed due to wild boar cases in Poland in 2014, compared against the reported cases in 2015 and then the procedure is repeated for 2015-2016. We find that long- and medium-distance spread of ASF (i.e. >30km) is very unlikely to have occurred due to boar dispersal, due in part to the generally short distances boar will travel (<20km on average). We also predict what the relative success of different control strategies would have been in 2015, if they were implemented in 2014. Results suggest that hunting of boar reduces the number of new cases, but a larger region is at risk of ASF compared to no control measure. Alternatively, introducing boar-proof fencing reduces the size of the region at risk in 2015, but not the total number of cases. Overall, our model suggests wild boar movement is only responsible for local transmission of disease, thus other pathways are more dominant in medium and long distance spread of the disease.

scholarly journals The African Swine Fever Epidemic in Wild Boar (Sus scrofa) in Lithuania (2014–2018)

2020 ◽  
Vol 7 (1) ◽  
pp. 15 ◽  
Author(s):  
Petras Mačiulskis ◽  
Marius Masiulis ◽  
Gediminas Pridotkas ◽  
Jūratė Buitkuvienė ◽  
Vaclovas Jurgelevičius ◽  
...  
Keyword(s):  
Wild Boar ◽  
Population Decline ◽  
African Swine Fever ◽  
Control Measures ◽  
Disease Spread ◽  
Wild Boar Population ◽  
Baltic States ◽  
Long Distance ◽  
First Case ◽  
The Baltic

In January 2014 the first case of African swine fever (ASF) in wild boar of the Baltic States was reported from Lithuania. It has been the first occurrence of the disease in Eastern EU member states. Since then, the disease spread further affecting not only the Baltic States and Poland but also south-eastern Europe, the Czech Republic and Belgium. The spreading pattern of ASF with its long-distance spread of several hundreds of kilometers on the one hand and the endemic situation in wild boar on the other is far from being understood. By analyzing data of ASF cases in wild boar along with implemented control measures in Lithuania from 2014–2018 this study aims to contribute to a better understanding of the disease. In brief, despite huge efforts to eradicate ASF, the disease is now endemic in the Lithuanian wild boar population. About 86% of Lithuanian’s territory is affected and over 3225 ASF cases in wild boar have been notified since 2014. The ASF epidemic led to a considerable decline in wild boar hunting bags. Intensified hunting might have reduced the wild boar population but this effect cannot be differentiated from the population decline caused by the disease itself. However, for ASF detection sampling of wild boar found dead supported by financial incentives turned out to be one of the most effective tools.

scholarly journals Agent-Based Modeling of the Hajj Rituals with the Possible Spread of COVID-19

2021 ◽  
Vol 13 (12) ◽  
pp. 6923
Author(s):  
Ali M. Al-Shaery ◽  
Bilal Hejase ◽  
Abdessamad Tridane ◽  
Norah S. Farooqi ◽  
Hamad Al Jassmi
Keyword(s):  
Control Strategies ◽  
Control Measure ◽  
Agent Based Modeling ◽  
Control Measures ◽  
Effective Control ◽  
Mass Gathering ◽  
Agent Based Model ◽  
Agent Based ◽  
Crowd Dynamics ◽  
The Impact

With the coronavirus (COVID-19) pandemic continuing to spread around the globe, there is an unprecedented need to develop different approaches to containing the pandemic from spreading further. One particular case of importance is mass-gathering events. Mass-gathering events have been shown to exhibit the possibility to be superspreader events; as such, the adoption of effective control strategies by policymakers is essential to curb the spread of the pandemic. This paper deals with modeling the possible spread of COVID-19 in the Hajj, the world’s largest religious gathering. We present an agent-based model (ABM) for two rituals of the Hajj: Tawaf and Ramy al-Jamarat. The model aims to investigate the effect of two control measures: buffers and face masks. We couple these control measures with a third control measure that can be adopted by policymakers, which is limiting the capacity of each ritual. Our findings show the impact of each control measure on the curbing of the spread of COVID-19 under the different crowd dynamics induced by the constraints of each ritual.

Characterizing the effectiveness of COVID-19 mitigation measures: A data-centric approach (Preprint)

2020 ◽  
Author(s):  
Lukman Olagoke ◽  
Ahmet E. Topcu
Keyword(s):  
Control Measure ◽  
Control Measures ◽  
World Health ◽  
Mitigation Measures ◽  
Effective Control ◽  
The World ◽  
Decision Making Processes ◽  
And Performance ◽  
Health Organization ◽  
The Impact

BACKGROUND COVID-19 represents a serious threat to both national health and economic systems. To curb this pandemic, the World Health Organization (WHO) issued a series of COVID-19 public safety guidelines. Different countries around the world initiated different measures in line with the WHO guidelines to mitigate and investigate the spread of COVID-19 in their territories. OBJECTIVE The aim of this paper is to quantitatively evaluate the effectiveness of these control measures using a data-centric approach. METHODS We begin with a simple text analysis of coronavirus-related articles and show that reports on similar outbreaks in the past strongly proposed similar control measures. This reaffirms the fact that these control measures are in order. Subsequently, we propose a simple performance statistic that quantifies general performance and performance under the different measures that were initiated. A density based clustering of based on performance statistic was carried out to group countries based on performance. RESULTS The performance statistic helps evaluate quantitatively the impact of COVID-19 control measures. Countries tend show variability in performance under different control measures. The performance statistic has negative correlation with cases of death which is a useful characteristics for COVID-19 control measure performance analysis. A web-based time-line visualization that enables comparison of performances and cases across continents and subregions is presented. CONCLUSIONS The performance metric is relevant for the analysis of the impact of COVID-19 control measures. This can help caregivers and policymakers identify effective control measures and reduce cases of death due to COVID-19. The interactive web visualizer provides easily digested and quick feedback to augment decision-making processes in the COVID-19 response measures evaluation. CLINICALTRIAL Not Applicable

An experimental evaluation of conventional control measures against the sheep tick, Ixodes ricinus (L.) (Acari: Ixodidae). II. The dynamics of the tick-host interaction

1985 ◽  
Vol 75 (3) ◽  
pp. 501-518 ◽  
Author(s):  
Sarah E. Randolph ◽  
Gordon M. Steele
Keyword(s):  
Ixodes Ricinus ◽  
Control Method ◽  
Control Strategies ◽  
Stocking Density ◽  
Experimental Manipulation ◽  
Control Measures ◽  
Effective Control ◽  
Contact Rate ◽  
Host Interaction ◽  
Questing Ticks

AbstractThe experimental manipulation of separate, but originally identical, populations of Ixodes ricinus (L.) by applying three conventional tick control measures in different enclosures on naturally infested moorland in Wales allowed the elements of the tick-host interaction to be analysed quantitatively and the effectiveness of the control methods to be compared. From the relationship between the sheep stocking density and the numbers of questing ticks picked up by fortnightly blanket-dragging in each enclosure, the death rate of ticks during their activity season and the rate of contact between sheep and ticks were calculated. From this, it was possible to investigate the effect of different stocking densities on the feeding success of ticks. A major factor determining the much lower contact rate for larvae than for nymphs was the different spatial distribution of questing ticks, clumped for larvae and random for nymphs. The non-random use by sheep of the three different vegetation zones in the paddock resulted in the highest contact rate between sheep and ticks in the pasture area, but tick survival was apparently highest in the bog area. Combining these factors resulted in the prediction that the bracken area was the least favourable habitat for ticks. In the two enclosures where the sheep were not treated with acaricide the mean tick loads on the sheep were similar, but the lower overall use of the pasture by the sheep in the low stocking density enclosure (2/ha) resulted in slightly lower tick loads there compared with those in the high stocking density enclosure (4/ha). The numbers of ticks counted in the second year showed that pasture spelling was the most effective control method, acaricide treatment was less effective, and the benefits of halving the stocking density were marginal. The implications of these results for control strategies are discussed.

scholarly journals The potential anti- African Swine Fever Virus effects of medium chain fatty acids on in vitro pig feed and water models

2020 ◽  
Author(s):  
Ha Thi Thanh Tran ◽  
Anh Duc Truong ◽  
Duc Viet Ly ◽  
Tuan Van Hoang ◽  
Chinh Thi Nguyen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Control Measures ◽  
Effective Control ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Water Models ◽  
Chain Fatty Acids

Abstract Background African swine fever (ASF) is an important disease affecting swine and has a significant economic loss on both the developed and developing world but due to the lack of vaccines, drug, and effective control measures, ASF virus remains a serious threat to global pork production. The activities of medium-chain fatty acids (MCFAs) against viral pathogens have been reported previously. However, the effects of this family on ASFV have been not yet investigated. In this study, we evaluated the potential effects of MCFAs in individual and synergistic forms, to prevent and/or reduce ASFV infection using in vitro feed and water models. Results The potential effects of MCFAs, including C8, C6-C8-C10 (1:1:1 ratio) and C8-C10-C12 (1:1:1 ratio) against a field ASFV strain isolated in Red River Delta region of Vietnam were further examined by real-time PCR in in vitro feed and water models. All tested products have shown a strong antiviral effect against ASFV infectivity at doses of 0.375% and 0.5% in both feed and water assays. Interestingly, the synergistic MCFAs have shown clearly their potential activities against ASFV in which at lower dose of 0.25%, pre-treatment with product 2 and 3 induced significant increases at the level of Cq value when compared to positive control and/or product 1 (P < 0.05). Conclusions To our knowledge, it is the first report on in vitro examination of the anti-ASFV activities of the MCFAs. Our findings suggested that all tested products, both individual and synergistic forms of MCFAs, have possessed a strong anti-ASFV effect and this effect is dose- dependence in in vitro feed and water models. Additionally, synergistic effects of MCFAs are more effective against ASFV when compared to individual form. The further studies focusing on in vivo anti-ASFV effects of MCFAs are very important to bring new insight into the mode of ASFV-reduced action by these compounds in swine feed and water consumption.

scholarly journals Emergence of African Swine Fever in Poland (2014–2021). Successes and Failures in Disease Eradication

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 738
Author(s):  
Grzegorz Woźniakowski ◽  
Zygmunt Pejsak ◽  
Artur Jabłoński
Keyword(s):  
Wild Boar ◽  
Management Strategies ◽  
African Swine Fever ◽  
Economic Loss ◽  
Wild Boar Population ◽  
Long Distance ◽  
Domestic Pig ◽  
Effective Measure ◽  
Disease Eradication ◽  
Pig Production

African swine fever (ASF) in Poland has been a major concern for pig production for the last seven years. The main constrains in ASF eradication in Poland are due to the high density of wild boar in ASF-affected areas of the country. Other factors, responsible for long-distance ASF spread to new regions of the country, are mainly related to human-mediated activity and lack of awareness of the potential disease threat to pig production. In the case of pig holdings, the only effective measure of ASF prevention is strict implementation of biosecurity rules. Despite many efforts to implement these measures, the disease occurred in a number of voivodeships, poviats and counties of Poland, primarily in eastern Poland; however, starting from 2019, also in the western part of the country. Further recommendations to eradicate ASF in Poland or at least to minimize the economic loss caused by ASF in pig production include effective wild boar population management strategies along with the implementation of strict biosecurity measures. The observations from the last seven years of ASF epizootic in Poland clearly indicate that the disease could not have been effectively controlled in wild boar population and could only be restricted in domestic pig population following severe biosecurity rules. As for ASF spread control in wild boar population, the measures applied in other EU countries include active wild boar carcass search and disposal along with sanitary and reduction hunting. These measures have also been shown non-effective. The only solution for future sustainable pig production in Poland seems to be strict collaboration between pig producers, veterinary inspection, and hunting associations.

scholarly journals A review of some important viral diseases of wild boars

2021 ◽  
Vol 37 (4) ◽  
pp. 235-254
Author(s):  
Jakov Nisavic ◽  
Andrea Radalj ◽  
Nenad Milic ◽  
Aleksandar Zivulj ◽  
Damir Benkovic ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Control Measure ◽  
Survival Rates ◽  
African Swine Fever ◽  
Classical Swine Fever ◽  
Control Measures ◽  
Detection Methods ◽  
Virus Species ◽  
Wild Boars ◽  
Prevalence Studies

Wild boars are one of the widest-ranging mammals worldwide and represent reservoirs for many important viruses. Disease outbreaks in domestic swine are often described as a consequence of contact with wild boars, and traditional rearing conditions are a particular risk factor. Examples of such diseases include classical swine fever (CSF), African swine fever (ASF), Aujeszky?s disease (AD), and diseases caused by porcine circoviruses and parvoviruses. Some viral infections causing high mortality rates are easily noticeable and thus reported, though many viruses infecting wildlife are insidious impacting survival rates and reproduction in wild animals. Samples from wild boars for laboratory testing are usually collected postmortem and include various tissues or blood sera. The recovery of viable viruses during virus isolation depends on the virus species and the condition of the sample. Since this method does not yield timely results, most diagnostic procedures are based on PCR or antigen detection methods. Serological surveys are inexpensive and appropriate for prevalence studies. When interpreting the results of diagnostic tests, both virus and host characteristics, and the epizootiological situation must be accounted for. Disease control techniques such as fencing or feeding wild boars cause animal aggregation and give rise to population density which favors pathogen maintenance in the environment. Hunting reduces the number of susceptible animals and is helpful as an additional control measure and for sampling. Available data on infectious disease dynamics in wild boars is scarce, and constant knowledge improvement on pathogenesis, clinical symptoms, risk factors, and adequate control measures are required.

scholarly journals Duodenoscope-Acquired Infections: Risk Factors to Consider

2021 ◽  
Vol 12 (03) ◽  
pp. 151-159
Author(s):  
Grace Thornhill ◽  
Brian Dunkin
Keyword(s):  
Risk Factors ◽  
At Risk ◽  
Antibiotic Sensitivity ◽  
Infectious Agent ◽  
Multidrug Resistant ◽  
Infection Risk ◽  
Control Measures ◽  
Risk Of Infection ◽  
New Device ◽  
Mesh Terms

AbstractIn the wake of highly publicized duodenoscope-associated outbreaks caused by multidrug-resistant organisms (MDRO), a herculean effort was made to understand the conditions that led to these transmission events. Although there is now a clearer picture on how these outbreaks happened, there are still significant data gaps when it comes to understanding the rate of duodenoscope-acquired infections (DAIs), especially in nonoutbreak situations. Recent publications indicate that DAIs are still occurring and suggest that infection rates are higher than currently believed. Given this data gap, it is important to identify those patient populations that are most at risk of postprocedure infection, so that appropriate infection control measures may be implemented. Although those patients receiving antibiotic prophylaxis are most at risk for infection, there are additional risk factors that should be considered. For the purposes of this review, risk factors for infection were divided into three broad categories as follows: (1) those that increase patient susceptibility to infection, (2) those related to the endoscopic procedure, and (3) those factors that put reusable duodenoscope inventories at risk of contamination. Infection risk is a complex interaction between the immune status of the patient, the characteristics of the infectious agent (antibiotic sensitivity, virulence factors, and epidemiology), and the environment of care. Because of this complexity, any assessment of the risk of infection should be performed on a case-by-case basis. There is a dearth of information on infection risk for those patients undergoing endoscopic retrograde cholangiopancreatograpy (ERCP), especially in the context of the development and implementation of new device technology, and new endoscopic procedures that are increasing in complexity. This narrative review was developed using the Medical Subject Heading (MeSH) terms to perform an electronic search in PubMed with the goal of generating a summary of the patient, procedural, and duodenoscope-associated factors that increase the risk of infection in patients undergoing ERCP. This review provides practical information regarding the segmentation of ERCP patients by infection risk, so that endoscopists can make informed decisions about the risk benefits of using enhanced duodenoscope technologies in the care of their patients.

scholarly journals Control Strategies for the Third wave of COVID-19 infection in India: A Mathematical Model Incorporating Vaccine Effectiveness

2022 ◽  
Author(s):  
Ashutosh Mahajan ◽  
Namitha Sivadas ◽  
Pooja Panda
Keyword(s):  
Transmission Rate ◽  
Control Strategies ◽  
Control Measures ◽  
Disease Spread ◽  
Effective Control ◽  
Third Wave ◽  
Social Distancing ◽  
Vaccination Rates ◽  
New Variant ◽  
The Future

The waning effectiveness of the COVID-19 vaccines and the emergence of a new variant Omicron has given rise to the possibility of another outbreak of the infection in India. COVID-19 has caused more than 34 million reported cases and 475 thousand deaths in India so far, and it has affected the country at the root level, socially as well as economically. After going through different control measures, mass vaccination has been achieved to a large extent for the highly populous country, and currently under progress. India has already been hit by a massive second wave of infection in April-June, 2021 mainly due to the delta variant, and might see a third wave in the near future that needs to be controlled with effective control strategies. In this paper, we present a compartmental epidemiological model with vaccinations incorporating the dose-dependent effectiveness. We study a possible sudden outbreak of SARS-CoV2 variants in the future, and bring out the associated predictions for various vaccination rates and point out optimum control measures. Our results show that for transmission rate 30% higher than the current rate due to emergence of new variant or relaxation of social distancing conditions, daily new cases can peak to 250k in March 2022, taking the second dose effectiveness dropping to 50% in the future. A combination of vaccination and controlled lockdown or social distancing is the key to tackling the current situation and for the coming few months. Our simulation results show that social distancing measures show better control over the disease spread than the higher vaccination rates. <br>

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