scholarly journals An Update on African Swine Fever Virology

Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 864 ◽  
Author(s):  
Axel Karger ◽  
Daniel Pérez-Núñez ◽  
Jesús Urquiza ◽  
Patricia Hinojar ◽  
Covadonga Alonso ◽  
...  

Animal diseases constitute a continuing threat to animal health, food safety, national economy, and the environment. Among those, African swine fever (ASF) is one of the most devastating viruses affecting pigs and wild suids due to the lack of vaccine or effective treatment. ASF is endemic in countries in sub-Saharan Africa, but since its introduction to the Caucasus region in 2007, a highly virulent strain of ASF virus (ASFV) has continued to circulate and spread into Eastern Europe and Russia, and most recently into Western Europe, China, and various countries of Southeast Asia. Given the importance of this disease, this review will highlight recent discoveries in basic virology with special focus on proteomic analysis, replication cycle, and some recent data on genes involved in cycle progression and viral–host interactions, such as I215L (E2 ubiquitin-conjugating enzyme), EP402R (CD2v), A104R (histone-like protein), QP509L, and Q706L (RNA helicases) or P1192R (Topoisomerase II). Taking into consideration the large DNA genome of ASFV and its complex interactions with the host, more studies and new approaches are to be taken to understand the basic virus–host interaction for ASFV. Proteomic studies are just paving the way for future research.

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1474
Author(s):  
Elisabeth Lopez ◽  
Juanita van Heerden ◽  
Laia Bosch-Camós ◽  
Francesc Accensi ◽  
Maria Jesus Navas ◽  
...  

African swine fever (ASF) has become the major threat for the global swine industry. Furthermore, the epidemiological situation of African swine fever virus (ASFV) in some endemic regions of Sub-Saharan Africa is worse than ever, with multiple virus strains and genotypes currently circulating in a given area. Despite the recent advances on ASF vaccine development, there are no commercial vaccines yet, and most of the promising vaccine prototypes available today have been specifically designed to fight the genotype II strains currently circulating in Europe, Asia, and Oceania. Previous results from our laboratory have demonstrated the ability of BA71∆CD2, a recombinant LAV lacking CD2v, to confer protection against homologous (BA71) and heterologous genotype I (E75) and genotype II (Georgia2007/01) ASFV strains, both belonging to same clade (clade C). Here, we extend these results using BA71∆CD2 as a tool trying to understand ASFV cross-protection, using phylogenetically distant ASFV strains. We first observed that five out of six (83.3%) of the pigs immunized once with 106 PFU of BA71∆CD2 survived the tick-bite challenge using Ornithodoros sp. soft ticks naturally infected with RSA/11/2017 strain (genotype XIX, clade D). Second, only two out of six (33.3%) survived the challenge with Ken06.Bus (genotype IX, clade A), which is phylogenetically more distant to BA71∆CD2 than the RSA/11/2017 strain. On the other hand, homologous prime-boosting with BA71∆CD2 only improved the survival rate to 50% after Ken06.Bus challenge, all suffering mild ASF-compatible clinical signs, while 100% of the pigs immunized with BA71∆CD2 and boosted with the parental BA71 virulent strain survived the lethal challenge with Ken06.Bus, without almost no clinical signs of the disease. Our results confirm that cross-protection is a multifactorial phenomenon that not only depends on sequence similarity. We believe that understanding this complex phenomenon will be useful for designing future vaccines for ASF-endemic areas.


2016 ◽  
Vol 371 (1709) ◽  
pp. 20150467 ◽  
Author(s):  
H. Charles J. Godfray ◽  
Daniel Mason-D'Croz ◽  
Sherman Robinson

Fungal diseases are major threats to the most important crops upon which humanity depends. Were there to be a major epidemic that severely reduced yields, its effects would spread throughout the globalized food system. To explore these ramifications, we use a partial equilibrium economic model of the global food system (IMPACT) to study a hypothetical severe but short-lived epidemic that reduces rice yields in the countries affected by 80%. We modelled a succession of epidemic scenarios of increasing severity, starting with the disease in a single country in southeast Asia and ending with the pathogen present in most of eastern Asia. The epidemic and subsequent crop losses led to substantially increased global rice prices. However, as long as global commodity trade was unrestricted and able to respond fast enough, the effects on individual calorie consumption were, to a large part, mitigated. Some of the worse effects were projected to be experienced by poor net-rice importing countries in sub-Saharan Africa, which were not affected directly by the disease but suffered because of higher rice prices. We critique the assumptions of our models and explore political economic pressures to restrict trade at times of crisis. We finish by arguing for the importance of ‘stress-testing’ the resilience of the global food system to crop disease and other shocks. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’.


Author(s):  
M-L. Penrith ◽  
W. Vosloo

African swine fever is one of the most important and serious diseases of domestic pigs. Its highly contagious nature and ability to spread over long distances make it one of the most feared diseases, since its devastating effects on pig production have been experienced not only in most of sub-Saharan Africa but also in western Europe, the Caribbean, Brazil and, most recently, the Caucasus. Unlike most diseases of livestock, there is no vaccine, and therefore prevention relies entirely upon preventing contact between the virus and the susceptible host. In order to do so it is necessary to understand the way in which the virus is transmitted and spreads. By implementing strict biosecurity measures that place barriers between the source of virus and the pigs it is possible to prevent infection. However, this has implications for free-ranging pig husbandry systems that are widespread in developing countries. Attempts to produce a vaccine are ongoing and new technology offers some hope for the future, but this will not remove the necessity for implementing adequate biosecurity on pig farms.


2021 ◽  
Author(s):  
Gustavo Machado ◽  
Trevor Farthing ◽  
Mathieu Andraud ◽  
Francisco Paulo Nunes Lopes ◽  
Cristina Lanzas

African swine fever (ASF) is considered the most impactful transboundary swine disease. In the absence of effective vaccines, control strategies are heavily dependent on mass depopulation and movement restrictions. Here we developed a nested multiscale model for the transmission of ASF, combining spatially explicit network model of animal movements with a deterministic compartmental model for the dynamics of two ASF strains within-pixels of 3 km x 3 km, amongst the pig population in one Brazilian state. The model outcomes are epidemic duration, number of secondary infected farms and pigs, and distance of ASF spread. The model also predicted the spatial distribution of ASF epidemics. We analyzed quarantine-based control interventions in the context of mortality trigger thresholds for the deployment of control strategies. The mean epidemic duration of a moderately virulent strain was 11.2 days assuming the first infection is detected (best-case scenario) and 15.9 days when detection is triggered at 10 % mortality. For a highly virulent strain, the epidemic duration was 6.5 days and 13.1 days, respectively. The distance from the source to infected locations and the spatial distribution was not dependent on strain virulence. Under the best-case scenario, we projected an average number of infected farms of 18.79 farms and 23.77 farms for the moderate and highly virulent strains, respectively. At 10% mortality-trigger, the predicted number of infected farms was on average 48.28 farms and 42.97 farms, respectively. We also demonstrated that the establishment of ring quarantine zones regardless of size (i.e., 5 km, 15 km) was outperformed by backward animal movement tracking. The proposed modeling framework provides an evaluation of ASF epidemic potential, providing a ranking of quarantine-based control strategies that could assist animal health authorities in planning the national preparedness and response plan.


2018 ◽  
Vol 92 (23) ◽  
Author(s):  
Alí Alejo ◽  
Tania Matamoros ◽  
Milagros Guerra ◽  
Germán Andrés

ABSTRACTAfrican swine fever virus (ASFV) is a large and complex DNA virus that causes a highly lethal swine disease for which there is no vaccine available. The ASFV particle, with an icosahedral multilayered structure, contains multiple polypeptides whose identity is largely unknown. Here, we analyzed by mass spectroscopy the protein composition of highly purified extracellular ASFV particles and performed immunoelectron microscopy to localize several of the detected proteins. The proteomic analysis identified 68 viral proteins, which account for 39% of the genome coding capacity. The ASFV proteome includes essentially all the previously described virion proteins and, interestingly, 44 newly identified virus-packaged polypeptides, half of which have an unknown function. A great proportion of the virion proteins are committed to the virus architecture, including two newly identified structural proteins, p5 and p8, which are derived from the core polyproteins pp220 and pp62, respectively. In addition, the virion contains a full complement of enzymes and factors involved in viral transcription, various enzymes implicated in DNA repair and protein modification, and some proteins concerned with virus entry and host defense evasion. Finally, 21 host proteins, many of them localized at the cell surface and related to the cortical actin cytoskeleton, were reproducibly detected in the ASFV particle. Immunoelectron microscopy strongly supports the suggestion that these host membrane-associated proteins are recruited during virus budding at actin-dependent membrane protrusions. Altogether, the results of this study provide a comprehensive model of the ASFV architecture that integrates both compositional and structural information.IMPORTANCEAfrican swine fever virus causes a highly contagious and lethal disease of swine that currently affects many countries of sub-Saharan Africa, the Caucasus, the Russian Federation, and Eastern Europe and has very recently spread to China. Despite extensive research, effective vaccines or antiviral strategies are still lacking, and many basic questions on the molecular mechanisms underlying the infective cycle remain. One such gap regards the composition and structure of the infectious virus particle. In the study described in this report, we identified the set of viral and host proteins that compose the virion and determined or inferred the localization of many of them. This information significantly increases our understanding of the biological and structural features of an infectious African swine fever virus particle and will help direct future research efforts.


Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 531
Author(s):  
Keke Wu ◽  
Jiameng Liu ◽  
Lianxiang Wang ◽  
Shuangqi Fan ◽  
Zhaoyao Li ◽  
...  

African swine fever (ASF) is a highly lethal contagious disease of swine caused by African swine fever virus (ASFV). At present, it is listed as a notifiable disease reported to the World Organization for Animal Health (OIE) and a class one animal disease ruled by Chinese government. ASF has brought significant economic losses to the pig industry since its outbreak in China in August 2018. In this review, we recapitulated the epidemic situation of ASF in China as of July 2020 and analyzed the influencing factors during its transmission. Since the situation facing the prevention, control, and eradication of ASF in China is not optimistic, safe and effective vaccines are urgently needed. In light of the continuous development of ASF vaccines in the world, the current scenarios and evolving trends of ASF vaccines are emphatically analyzed in the latter part of the review. The latest research outcomes showed that attempts on ASF gene-deleted vaccines and virus-vectored vaccines have proven to provide complete homologous protection with promising efficacy. Moreover, gaps and future research directions of ASF vaccine are also discussed.


2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  

Abstract Antimicrobial resistance (AMR) is one of the biggest contemporary threats to global health, food security and development. AMR is associated with longer illness, higher mortality and higher health care costs, and threatens the success of many disease interventions including surgery, chemotherapy and the fight against HIV, TB and Malaria. The risks and impacts of AMR are truly universal and global, putting everyone at risk across demographic, socioeconomic and geographic boundaries. AMR is a “wicked” problem driven by a range of complex, structural and interconnected factors, including in sectors related to human health, animal health, agriculture and the environment. Research on AMR is therefore needed not only from, but which bridges across, diverse disciplines including biomedicine, public health and the environmental, animal, social and political sciences. Despite calls for coordinated action on AMR, traditional siloes between sectors and disciplines, and from research to practice, remain difficult to bridge. Many efforts have strengthened communication and coordination but remain essentially focused on “drugs and bugs”, stopping short of achieving the type of radical, integrative and trans-border (disciplinary, sectoral, national, etc) collaboration needed to explore and effectively tackle this complex challenge. The goal of this workshop is to create a space for dedicated discussion between professionals from diverse disciplines, sectors and settings to explore the following questions: What key questions or challenges for understanding and tackling AMR (from a research, policy or practice perspective) need to be explored using an interdisciplinary research approach?What thematic intersections, tensions and synergies exist between different disciplines conducting research on or relevant to AMR? What different theoretical perspectives and methodological approaches can be brought together to answer such questions?How can we create bridges and strengthen solidarity between professionals in different disciplines, sectors and stakeholder groups to foster the type of systematic, inter-/trans-disciplinary research needed? How can we ensure the knowledge generated informs evidence-based policy and practice to effectively and equitably tackle AMR?What initiatives for inter-/trans-disciplinary research on AMR have been effective and what can be learned to inform future research? Following a brief introduction of key concepts and objectives, two presentations will provide input from research on the macro-structural drivers of AMR, which demonstrate the importance and value of different disciplinary research on this topic. A third presentation will explore equity and gender considerations in tackling AMR. The subsequent discussion will examine the above questions by tapping into the expertise, experience and perspectives of the presenters and participants. The workshop will close with a summary of lessons learnt and directions for future research. Key messages New forms of inter- and trans-disciplinary, translational research are needed to understand the complex drivers and dynamics of antimicrobial resistance and how to address this major global threat. Meaningful exchange is needed to identify concrete ways to overcome the methodological, practical and other challenges to conducting systematic, inter-/trans-disciplinary research on AMR.


2020 ◽  
Vol 30 (3) ◽  
pp. 187-204
Author(s):  
Lina Vidauskytė ◽  

This essay analyzes Karl Jaspers’ conception of the Axial Age and the comparative idea of paradigmatic individuals (Socrates, Buddha, Confucius, Jesus) among other relevant ideas (philosophical faith, biblical religion) in the light of post-secularity. The special focus is laid on the post-war situation in Western Europe which was one of the main factors of the formation of the aforementioned conceptions and ideas. The disaster which was brought by uncontrolled nationalism in Germany forced Jaspers to rethink the crisis of humanism after World War II. Using a comparative method Jaspers seeks a unity of human spirit and with this gesture his thinking appears to be a desire to have a foundation for the common being of contemporary society. Jaspers’ interpretation of paradigmatic individuals stimulated future research on comparative civilizational philosophies.


2020 ◽  
Vol 57 (4) ◽  
pp. 476-489 ◽  
Author(s):  
Giovanni Di Teodoro ◽  
Giuseppe Marruchella ◽  
Andrea Di Provvido ◽  
Anna Rita D’Angelo ◽  
Gianluca Orsini ◽  
...  

Contagious bovine pleuropneumonia (CBPP) is a respiratory disease of cattle that is listed as notifiable by the World Organization for Animal Health. It is endemic in sub-Saharan Africa and causes important productivity losses due to the high mortality and morbidity rates. CBPP is caused by Mycoplasma mycoides subsp. mycoides ( Mmm) and is characterized by severe fibrinous bronchopneumonia and pleural effusion during the acute to subacute stages and by pulmonary sequestra in chronic cases. Additional lesions can be detected in the kidneys and in the carpal and tarsal joints of calves. Mmm infection occurs through the inhalation of infected aerosol droplets. After the colonization of bronchioles and alveoli, Mmm invades blood and lymphatic vessels and causes vasculitis. Moreover, Mmm can be occasionally demonstrated in blood and in a variety of other tissues. In the lung, Mmm antigen is commonly detected on bronchiolar and alveolar epithelial cells, in lung phagocytic cells, within the wall of blood and lymphatic vessels, inside necrotic areas, and within tertiary lymphoid follicles. Mmm antigen can also be present in the cytoplasm of macrophages within lymph node sinuses, in the germinal center of lymphoid follicles, in glomerular endothelial cells, and in renal tubules. A complete pathological examination is of great value for a rapid presumptive diagnosis, but laboratory investigations are mandatory for definitive diagnosis. The purpose of this review is to describe the main features of CBPP including the causative agent, history, geographic distribution, epidemiology, clinical course, diagnosis, and control. A special focus is placed on gross and microscopic lesions in order to familiarize veterinarians with the pathology and pathogenesis of CBPP.


2020 ◽  
Vol 12 (24) ◽  
pp. 4190
Author(s):  
Siyamthanda Gxokwe ◽  
Timothy Dube ◽  
Dominic Mazvimavi

Wetlands are ranked as very diverse ecosystems, covering about 4–6% of the global land surface. They occupy the transition zones between aquatic and terrestrial environments, and share characteristics of both zones. Wetlands play critical roles in the hydrological cycle, sustaining livelihoods and aquatic life, and biodiversity. Poor management of wetlands results in the loss of critical ecosystems goods and services. Globally, wetlands are degrading at a fast rate due to global environmental change and anthropogenic activities. This requires holistic monitoring, assessment, and management of wetlands to prevent further degradation and losses. Remote-sensing data offer an opportunity to assess changes in the status of wetlands including their spatial coverage. So far, a number of studies have been conducted using remotely sensed data to assess and monitor wetland status in semi-arid and arid regions. A literature search shows a significant increase in the number of papers published during the 2000–2020 period, with most of these studies being in semi-arid regions in Australia and China, and few in the sub-Saharan Africa. This paper reviews progress made in the use of remote sensing in detecting and monitoring of the semi-arid and arid wetlands, and focuses particularly on new insights in detection and monitoring of wetlands using freely available multispectral sensors. The paper firstly describes important characteristics of wetlands in semi-arid and arid regions that require monitoring in order to improve their management. Secondly, the use of freely available multispectral imagery for compiling wetland inventories is reviewed. Thirdly, the challenges of using freely available multispectral imagery in mapping and monitoring wetlands dynamics like inundation, vegetation cover and extent, are examined. Lastly, algorithms for image classification as well as challenges associated with their uses and possible future research are summarised. However, there are concerns regarding whether the spatial and temporal resolutions of some of the remote-sensing data enable accurate monitoring of wetlands of varying sizes. Furthermore, it was noted that there were challenges associated with the both spatial and spectral resolutions of data used when mapping and monitoring wetlands. However, advancements in remote-sensing and data analytics provides new opportunities for further research on wetland monitoring and assessment across various scales.


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