scholarly journals Current State of Global African Swine Fever Vaccine Development under the Prevalence and Transmission of ASF in China

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 531
Author(s):  
Keke Wu ◽  
Jiameng Liu ◽  
Lianxiang Wang ◽  
Shuangqi Fan ◽  
Zhaoyao Li ◽  
...  
Keyword(s):  
Vaccine Development ◽  
African Swine Fever Virus ◽  
Animal Health ◽  
African Swine Fever ◽  
Economic Losses ◽  
Future Research ◽  
Chinese Government ◽  
Current State ◽  
The World ◽  
World Organization

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.

scholarly journals Development of a chemiluminescence immunoassay to accurately detect African swine fever virus antibodies in serum

2021 ◽  
Author(s):  
Yong Yang ◽  
Changjie Lv ◽  
Junqing Fan ◽  
Ya Zhao ◽  
Lili Jiang ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Animal Health ◽  
Serum Antibody ◽  
African Swine Fever ◽  
Animal Husbandry ◽  
Economic Losses ◽  
Effective Vaccine ◽  
Serum Samples ◽  
Working Parameters ◽  
World Organization

AbstractThe outbreak of African swine fever (ASF) has caused significant economic losses to animal husbandry worldwide. Currently, there is no effective vaccine or treatment available to control the disease, and therefore, efficient disease control is dependent on early detection and diagnosis of ASF virus (ASFV). In this study, a chemiluminescent immunoassay (CLIA) was developed using the ASFV protein p54 as a serum diagnostic antigen and an anti-p54 monoclonal antibody. After optimizing the working parameters of the CLIA, the sensitivity of the established CLIA was 1:128, ASFV-specific serum antibody was identified, and there was no cross-reaction with other swine virus antibodies. After testing 49 clinical serum samples, the consistency rate between the CLIA and the World Organization for Animal Health (OIE) recommended commercial kit was 100%. Thus, this CLIA had a high degree of specificity, sensitivity, and reliability, and could be used as a rapid detection method for epidemiological investigations of ASFV infection.

scholarly journals Computational Analysis of African Swine Fever Virus Protein Space for the Design of an Epitope-Based Vaccine Ensemble

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1078 ◽  
Author(s):  
Albert Ros-Lucas ◽  
Florencia Correa-Fiz ◽  
Laia Bosch-Camós ◽  
Fernando Rodriguez ◽  
Julio Alonso-Padilla
Keyword(s):  
T Cell ◽  
Vaccine Development ◽  
De Novo ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Virus Protein ◽  
Hemorrhagic Disease ◽  
Starting Point

African swine fever virus is the etiological agent of African swine fever, a transmissible severe hemorrhagic disease that affects pigs, causing massive economic losses. There is neither a treatment nor a vaccine available, and the only method to control its spread is by extensive culling of pigs. So far, classical vaccine development approaches have not yielded sufficiently good results in terms of concomitant safety and efficacy. Nowadays, thanks to advances in genomic and proteomic techniques, a reverse vaccinology strategy can be explored to design alternative vaccine formulations. In this study, ASFV protein sequences were analyzed using an in-house pipeline based on publicly available immunoinformatic tools to identify epitopes of interest for a prospective vaccine ensemble. These included experimentally validated sequences from the Immune Epitope Database, as well as de novo predicted sequences. Experimentally validated and predicted epitopes were prioritized following a series of criteria that included evolutionary conservation, presence in the virulent and currently circulating variant Georgia 2007/1, and lack of identity to either the pig proteome or putative proteins from pig gut microbiota. Following this strategy, 29 B-cell, 14 CD4+ T-cell and 6 CD8+ T-cell epitopes were selected, which represent a starting point to investigating the protective capacity of ASFV epitope-based vaccines.

scholarly journals African Swine Fever in Cameroon: A Review

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 421
Author(s):  
Ebanja Joseph Ebwanga ◽  
Stephen Mbigha Ghogomu ◽  
Jan Paeshuyse
Keyword(s):  
African Swine Fever Virus ◽  
Central Africa ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Future Research ◽  
Genotype I ◽  
Traditional System ◽  
Pork Industry ◽  
Domestic Cycle

African swine fever (ASF) is a hemorrhagic contagious porcine disease caused by the African swine fever virus. The disease poses enormous problems to the pork industry with pig mortality ranging from 30% to 100%, depending on the virulence of the virus circulating. Cameroon, situated in Central Africa is one of the countries in which the African swine fever virus (ASFV) has been endemic since its first outbreak in 1982. The disease is a major problem to the pig industry causing huge economic losses. A clear and concise review on ASF in Cameroon relating to the entry and current genotype of the virus, epidemiology, pathogenesis and economic impact is lacking. A thorough literature search revealed: (1) The virus entered the country in 1982 and caused the death of 80% of the pigs. (2) All isolates belong to serogroup I and only Genotype I is circulating in Cameroon principally in the domestic cycle as there are neither soft ticks nor warthog in the pig production regions sampled. (3) 70% of the pig farmers are involved in the traditional system of production with local and hybrid breeds of pigs with minimal input. (4) The country is endemic to the virus with huge economic losses. (5) So far, very little research has been effected on ASFV in Cameroon. This review gives a detailed overview of the situation of African swine fever virus (ASFV) in the country along with potential avenues for future research into ASFV in Cameroon.

scholarly journals Effectiveness of Chemical Compounds Used against African Swine Fever Virus in Commercial Available Disinfectants

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 878
Author(s):  
Małgorzata Juszkiewicz ◽  
Marek Walczak ◽  
Natalia Mazur-Panasiuk ◽  
Grzegorz Woźniakowski
Keyword(s):  
Caustic Soda ◽  
Sodium Hypochlorite ◽  
African Swine Fever Virus ◽  
Animal Health ◽  
Virus Titer ◽  
African Swine Fever ◽  
Chemical Compounds ◽  
Fever Virus ◽  
Economic Losses ◽  
Potassium Peroxymonosulfate

African swine fever (ASF) causes huge economic losses and is one of most dangerous diseases of pigs. The disease is known for almost 100 years, an effective vaccine or treatment is still unavailable, only proper biosecurity measures, including disinfection, are being applied, in order to prevent disease outbreaks. Eight active substances, i.e., formaldehyde, sodium hypochlorite, caustic soda, glutaraldehyde, phenol, benzalkonium chloride, potassium peroxymonosulfate and acetic acid, were tested, in order to confirm their effectiveness against African swine fever virus (ASFV). This specific selection was done based on the World Organisation for Animal Health (OIE)’s recommendation and previous disinfectant studies on surfaces. The result of our study shows that most of them inactivate the virus, in recommended concentrations. In order to reduce the cytotoxicity of the four substances, Microspin S-400 HR columns were applied, therefore making it possible to demonstrate four logarithms virus titer reduction. Sodium hypochlorite, glutaraldehyde, caustic soda and potassium peroxymonosulfate showed the best ASFV inactivation rates, achieving titer reductions over 5 logs. Despite microfiltration, the virucidal activity of formaldehyde was not assessable, due to its high cytotoxicity. Our results showed that cleaning is particularly important, because removal of the soiling provides improved effectiveness of the tested chemical compounds.

scholarly journals One Year of African Swine Fever Outbreak in China

2020 ◽  
Author(s):  
Dapeng Tao ◽  
Daipeng Sun ◽  
Shu Wei ◽  
Tongqing An ◽  
Guoshun Shen ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Production Capacity ◽  
African Swine Fever ◽  
Integrated Approach ◽  
Economic Losses ◽  
Anthropogenic Factors ◽  
Chinese Government ◽  
Science And Policy ◽  
Wild Boars ◽  
Domestic Pigs

Abstract Background: African swine fever (ASF) is a major threat to domestic pigs and wild boars. Since 2018, ASF outbreak has been ongoing in China. As of August 3, 2019, a total of 151 ASF outbreaks reported in China have caused severe economic losses for many pig farmers and pork producers. The present study is to analyze the epidemiologic characteristics of ASF outbreak that occurred in several regions across China during the period August 2018- August 2019. Particularly focusing on the epidemic distribution, main transmission routes, incidence/fatality, impact on pig production capacity, and the main preventive measures adopting to mitigate the risk of ASF spread in pig farming systems by Chinese government. Results: The data show that the importance of seasonality effect, spatial distribution and the anthropogenic factors on the transmission of ASF, and further suggest that effective ASF risk management in China will require a comprehensive and integrated approach linking science and policy and will need to involve all relevant stakeholders to develop realistic policies. Conclusions: This provides an improved scientific basis to optimize current interventions as well as develop new tools and strategies to reduce the risk of African swine fever virus (ASFV) transmission to domestic pigs and wild boars.

scholarly journals Validation of a Real Time PCR for Classical Swine Fever Diagnosis

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Natanael Lamas Dias ◽  
Antônio Augusto Fonseca Júnior ◽  
Anapolino Macedo Oliveira ◽  
Érica Bravo Sales ◽  
Bruna Rios Coelho Alves ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Animal Health ◽  
Classical Swine Fever ◽  
Viral Disease ◽  
Economic Losses ◽  
Pcr Assay ◽  
Free Zone ◽  
The World ◽  
World Organization ◽  
Different Tissues

The viral disease classical swine fever (CSF), caused by aPestivirus, is one of the major causes of economic losses for pig farming. The aim of this work was to validate a RT-qPCR using Taqman for detection of CSF in swine tissues. The parameters for the validation followed the specifications of the Manual of Diagnostic Tests and Vaccines for Terrestrial Animals of the World Organization for Animal Health (OIE) and the guide ABNT NBR ISO/IEC 17025:2005. The analysis of the 5′NTR region of CSF virus was performed in 145 samples from 29 infected pigs and in 240 samples from 80 pigs originated in the Brazilian CSF-free zone. The tissues tested were spleen, kidney, blood, tonsils, and lymph nodes. Sequencing of the positive samples for 5′NTR region was performed to evaluate the specificity of the RT-qPCR. Tests performed for the RT-qPCR validation demonstrated that the PCR assay was efficient in detecting RNA from CSF virus in all materials from different tissues of infected animals. Furthermore, RNA from CSF virus was not detected in samples of swine originated from the Brazilian CSF-free zone. Hence, it is concluded that RT-qPCR can be used as a complementary diagnostic for CSF.

scholarly journals Structure of African Swine Fever Virus and Associated Molecular Mechanisms Underlying Infection and Immunosuppression: A Review

2021 ◽  
Vol 12 ◽  
Author(s):  
Yue Wang ◽  
Weifang Kang ◽  
Wenping Yang ◽  
Jing Zhang ◽  
Dan Li ◽  
...  
Keyword(s):  
Immune Response ◽  
Molecular Mechanism ◽  
Molecular Mechanisms ◽  
African Swine Fever Virus ◽  
Animal Health ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Cell Immune Response ◽  
Effective Vaccine

African swine fever (ASF) is an acute, highly contagious, and deadly infectious disease. The mortality rate of the most acute and acute ASF infection is almost 100%. The World Organization for Animal Health [Office International des épizooties (OIE)] lists it as a legally reported animal disease and China lists it as class I animal epidemic. Since the first diagnosed ASF case in China on August 3, 2018, it has caused huge economic losses to animal husbandry. ASF is caused by the African swine fever virus (ASFV), which is the only member of Asfarviridae family. ASFV is and the only insect-borne DNA virus belonging to the Nucleocytoplasmic Large DNA Viruses (NCLDV) family with an icosahedral structure and an envelope. Till date, there are still no effective vaccines or antiviral drugs for the prevention or treatment of ASF. The complex viral genome and its sophisticated ability to regulate the host immune response may be the reason for the difficulty in developing an effective vaccine. This review summarizes the recent findings on ASFV structure, the molecular mechanism of ASFV infection and immunosuppression, and ASFV-encoded proteins to provide comprehensive proteomic information for basic research on ASFV. In addition, it also analyzes the results of previous studies and speculations on the molecular mechanism of ASFV infection, which aids the study of the mechanism of clinical pathological phenomena, and provides a possible direction for an intensive study of ASFV infection mechanism. By summarizing the findings on molecular mechanism of ASFV- regulated host cell immune response, this review provides orientations and ideas for fundamental research on ASFV and provides a theoretical basis for the development of protective vaccines against ASFV.

scholarly journals Development of a Potential Penside Colorimetric LAMP Assay Using Neutral Red for Detection of African Swine Fever Virus

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Wang ◽  
Junfei Dai ◽  
Yongsheng Liu ◽  
Jifei Yang ◽  
Qian Hou ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Animal Health ◽  
Colorimetric Detection ◽  
Monitoring Program ◽  
African Swine Fever ◽  
Lamp Assay ◽  
Neutral Red ◽  
Economic Losses ◽  
One Step ◽  
And Control

African swine fever (ASF) has caused huge economic losses to the swine industry worldwide. Since there is no commercial ASF vaccine available, an early diagnosis is extremely important to prevent and control the disease. In this study, ASF virus (ASFV) capsid protein-encoding gene (p72) was selected and used to design primers for establishing a one-step visual loop-mediated isothermal amplification (LAMP) assay with neutral red, a pH-sensitive dye, as the color shift indicator. Neutral red exhibited a sharp contrast of color change from faint orange (negative) to pink (positive) during LAMP for detection of ASFV. The designed primer set targeting highly conserved region of the p72 gene was highly specific to ASFV and showed no cross-reactivity with other swine viruses. The detection limit for the one-step visual LAMP developed was 10 copies/reaction based on the recombinant plasmid containing the p72 gene of ASFV. More importantly, the developed one-step visual LAMP showed high consistency with the results of the real-time polymerase chain reaction (qPCR) method recommended by World Organization for Animal Health (OIE). Furthermore, the results demonstrate that the colorimetric detection with this LAMP assay could be directly applied for the whole blood and serum samples without requiring genome extraction. Based on our results, the developed one-step visual LAMP assay is a promising penside diagnostic tool for development of early and cost-effective ASF monitoring program that would greatly contribute to the prevention and control of ASF.

scholarly journals Genotyping of African Swine Fever Virus (ASFV) Isolates in Romania with the First Report of Genotype II in Symptomatic Pigs

2021 ◽  
Vol 8 (12) ◽  
pp. 290
Author(s):  
Andrei Ungur ◽  
Cristina Daniela Cazan ◽  
Luciana Cătălina Panait ◽  
Marian Taulescu ◽  
Oana Maria Balmoș ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Animal Health ◽  
African Swine Fever ◽  
Fever Virus ◽  
Swine Industry ◽  
First Report ◽  
The World ◽  
First Time ◽  
Genotype Ii

The World Organisation for Animal Health has listed African swine fever as the most important deadly disease in domestic swine around the world. The virus was recently brought from South-East Africa to Georgia in 2007, and it has since expanded to Russia, Eastern Europe, China, and Southeast Asia, having a devastating impact on the global swine industry and economy. In this study, we report for the first time the molecular characterization of nine African swine fever virus (ASFV) isolates obtained from domestic pigs in Mureş County, Romania. All nine Romanian samples clustered within p72 genotype II and showed 100% identity with all compared isolates from Georgia, Armenia, Russia, Azerbaijan, Ukraine, Belarus, Lithuania, and Poland. This is the first report of ASFV genotype II in the country.

scholarly journals Live Attenuated African Swine Fever Viruses as Ideal Tools to Dissect the Mechanisms Involved in Cross-Protection

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1474
Author(s):  
Elisabeth Lopez ◽  
Juanita van Heerden ◽  
Laia Bosch-Camós ◽  
Francesc Accensi ◽  
Maria Jesus Navas ◽  
...  
Keyword(s):  
Vaccine Development ◽  
African Swine Fever Virus ◽  
Virulent Strain ◽  
Sequence Similarity ◽  
Clinical Signs ◽  
African Swine Fever ◽  
Cross Protection ◽  
Sub Saharan Africa ◽  
Genotype I ◽  
Genotype Ii

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.

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