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Van Borm S, Dellicour S, Martin DP, Lemey P, Agianniotaki EI, Chondrokouki ED, Vidanovic D, Vaskovic N, Petroviċ T, Laziċ S, Koleci X, Vodica A, Djadjovski I, Krstevski K, Vandenbussche F, Haegeman A, De Clercq K, Mathijs E. Complete genome reconstruction of the global and European regional dispersal history of the lumpy skin disease virus. J Virol 2023; 97:e0139423. [PMID: 37905838 PMCID: PMC10688313 DOI: 10.1128/jvi.01394-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 10/02/2023] [Indexed: 11/02/2023] Open
Abstract
IMPORTANCE Lumpy skin disease virus (LSDV) has a complex epidemiology involving multiple strains, recombination, and vaccination. Its DNA genome provides limited genetic variation to trace outbreaks in space and time. Sequencing of LSDV whole genomes has also been patchy at global and regional scales. Here, we provide the first fine-grained whole genome sequence sampling of a constrained LSDV outbreak (southeastern Europe, 2015-2017), which we analyze along with global publicly available genomes. We formally evaluate the past occurrence of recombination events as well as the temporal signal that is required for calibrating molecular clock models and subsequently conduct a time-calibrated spatially explicit phylogeographic reconstruction. Our study further illustrates the importance of accounting for recombination events before reconstructing global and regional dynamics of DNA viruses. More LSDV whole genomes from endemic areas are needed to obtain a comprehensive understanding of global LSDV dispersal dynamics.
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Affiliation(s)
- Steven Van Borm
- Scientific Directorate Animal Infectious Diseases, Sciensano, Brussels, Belgium
| | - Simon Dellicour
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, Brussels, Belgium
- Laboratory for Clinical and Epidemiological Virology, Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Leuven, Belgium
| | - Darren P. Martin
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Philippe Lemey
- Laboratory for Clinical and Epidemiological Virology, Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Leuven, Belgium
| | - Eirini I. Agianniotaki
- National Reference Laboratory for Capripoxviruses, Department of Molecular Diagnostics, FMD, Virological, Rickettsial and Exotic Diseases, Directorate of Athens Veterinary Center, Ministry of Rural Development and Food, Athens, Greece
| | - Eleni D. Chondrokouki
- National Reference Laboratory for Capripoxviruses, Department of Molecular Diagnostics, FMD, Virological, Rickettsial and Exotic Diseases, Directorate of Athens Veterinary Center, Ministry of Rural Development and Food, Athens, Greece
| | - Dejan Vidanovic
- Department for laboratory diagnostics, Veterinary Specialized Institute, Kraljevo, Serbia
| | - Nikola Vaskovic
- Department for laboratory diagnostics, Veterinary Specialized Institute, Kraljevo, Serbia
| | - Tamaš Petroviċ
- Department for Virology, Scientific Veterinary Institute, Novi Sad, Serbia
| | - Sava Laziċ
- Department for Virology, Scientific Veterinary Institute, Novi Sad, Serbia
| | - Xhelil Koleci
- Faculty of Veterinary Medicine, The Agricultural University of Tirana, Tirana, Albania
| | - Ani Vodica
- Animal Health Department, Food Safety and Veterinary Institute, Tirana, Albania
| | - Igor Djadjovski
- Faculty of Veterinary Medicine, Ss. Cyril and Methodius University in Skopje, Skopje, Macedonia
| | - Kiril Krstevski
- Faculty of Veterinary Medicine, Ss. Cyril and Methodius University in Skopje, Skopje, Macedonia
| | - Frank Vandenbussche
- Scientific Directorate Animal Infectious Diseases, Sciensano, Brussels, Belgium
| | - Andy Haegeman
- Scientific Directorate Animal Infectious Diseases, Sciensano, Brussels, Belgium
| | - Kris De Clercq
- Scientific Directorate Animal Infectious Diseases, Sciensano, Brussels, Belgium
| | - Elisabeth Mathijs
- Scientific Directorate Animal Infectious Diseases, Sciensano, Brussels, Belgium
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Haegeman A, Sohier C, Mostin L, De Leeuw I, Van Campe W, Philips W, De Regge N, De Clercq K. Evidence of Lumpy Skin Disease Virus Transmission from Subclinically Infected Cattle by Stomoxys calcitrans. Viruses 2023; 15:1285. [PMID: 37376585 DOI: 10.3390/v15061285] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 06/29/2023] Open
Abstract
Lumpy skin disease virus (LSDV) is a vector-transmitted capripox virus that causes disease in cattle. Stomoxys calcitrans flies are considered to be important vectors as they are able to transmit viruses from cattle with the typical LSDV skin nodules to naive cattle. No conclusive data are, however, available concerning the role of subclinically or preclinically infected cattle in virus transmission. Therefore, an in vivo transmission study with 13 donors, experimentally inoculated with LSDV, and 13 naïve acceptor bulls was performed whereby S. calcitrans flies were fed on either subclinical- or preclinical-infected donor animals. Transmission of LSDV from subclinical donors showing proof of productive virus replication but without formation of skin nodules was demonstrated in two out of five acceptor animals, while no transmission was seen from preclinical donors that developed nodules after Stomoxys calcitrans flies had fed. Interestingly, one of the acceptor animals which became infected developed a subclinical form of the disease. Our results show that subclinical animals can contribute to virus transmission. Therefore, stamping out only clinically diseased LSDV-infected cattle could be insufficient to completely halt the spread and control of the disease.
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Affiliation(s)
- Andy Haegeman
- Sciensano, Infectious Diseases in Animals, Exotic and Vector-Borne Diseases, Groeselenberg 99, B-1180 Brussels, Belgium
| | - Charlotte Sohier
- Sciensano, Infectious Diseases in Animals, Exotic and Vector-Borne Diseases, Groeselenberg 99, B-1180 Brussels, Belgium
| | - Laurent Mostin
- Sciensano, Experimental Center Machelen, Kerklaan 68, B-1830 Machelen, Belgium
| | - Ilse De Leeuw
- Sciensano, Infectious Diseases in Animals, Exotic and Vector-Borne Diseases, Groeselenberg 99, B-1180 Brussels, Belgium
| | - Willem Van Campe
- Sciensano, Experimental Center Machelen, Kerklaan 68, B-1830 Machelen, Belgium
| | - Wannes Philips
- EURL for Diseases Caused by Capripox Viruses, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium
| | - Nick De Regge
- Sciensano, Infectious Diseases in Animals, Exotic and Vector-Borne Diseases, Groeselenberg 99, B-1180 Brussels, Belgium
| | - Kris De Clercq
- Sciensano, Infectious Diseases in Animals, Exotic and Vector-Borne Diseases, Groeselenberg 99, B-1180 Brussels, Belgium
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Omoniwa DO, Meki IK, Kudi CA, Sackey AK, Aminu M, Adedeji AJ, Meseko CA, Luka PD, Asala OO, Adole JA, Atai RB, Atuman YJ, Settypalli TBK, Cattoli G, Lamien CE. Poxvirus Infections in Dairy Farms and Transhumance Cattle Herds in Nigeria. Viruses 2023; 15:v15051051. [PMID: 37243137 DOI: 10.3390/v15051051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
Lumpy Skin disease (LSD) is an economically important disease in cattle caused by the LSD virus (LSDV) of the genus Capripoxvirus, while pseudocowpox (PCP) is a widely distributed zoonotic cattle disease caused by the PCP virus (PCPV) of the genus Parapoxvirus. Though both viral pox infections are reportedly present in Nigeria, similarities in their clinical presentation and limited access to laboratories often lead to misdiagnosis in the field. This study investigated suspected LSD outbreaks in organized and transhumance cattle herds in Nigeria in 2020. A total of 42 scab/skin biopsy samples were collected from 16 outbreaks of suspected LSD in five northern States of Nigeria. The samples were analyzed using a high-resolution multiplex melting (HRM) assay to differentiate poxviruses belonging to Orthopoxvirus, Capripoxvirus, and Parapoxvirus genera. LSDV was characterized using four gene segments, namely the RNA polymerase 30 kDa subunit (RPO30), G-protein-coupled receptor (GPCR), the extracellular enveloped virus (EEV) glycoprotein and CaPV homolog of the variola virus B22R. Likewise, the partial B2L gene of PCPV was also analyzed. Nineteen samples (45.2%) were positive according to the HRM assay for LSDV, and five (11.9%) were co-infected with LSDV and PCPV. The multiple sequence alignments of the GPCR, EEV, and B22R showed 100% similarity among the Nigerian LSDV samples, unlike the RPO30 phylogeny, which showed two clusters. Some of the Nigerian LSDVs clustered within LSDV SG II were with commonly circulating LSDV field isolates in Africa, the Middle East, and Europe, while the remaining Nigerian LSDVs produced a unique sub-group. The B2L sequences of Nigerian PCPVs were 100% identical and clustered within the PCPV group containing cattle/Reindeer isolates, close to PCPVs from Zambia and Botswana. The results show the diversity of Nigerian LSDV strains. This paper also reports the first documented co-infection of LSDV and PCPV in Nigeria.
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Affiliation(s)
- David Oludare Omoniwa
- Department of Veterinary Medicine, Surgery and Radiology, University of Jos, Jos 930001, Plateau State, Nigeria
- Department of Veterinary Medicine, Ahmadu Bello University, Zaria 810211, Kaduna State, Nigeria
| | - Irene Kasindi Meki
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria
| | - Caleb Ayuba Kudi
- Department of Veterinary Medicine, Ahmadu Bello University, Zaria 810211, Kaduna State, Nigeria
| | - Anthony Kojo Sackey
- Department of Veterinary Medicine, Ahmadu Bello University, Zaria 810211, Kaduna State, Nigeria
| | - Maryam Aminu
- Department of Microbiology, Ahmadu Bello University, Zaria 810211, Kaduna State, Nigeria
| | | | | | - Pam Dachung Luka
- National Veterinary Research Institute, Vom 930103, Plateau State, Nigeria
| | | | - Jolly Amoche Adole
- National Veterinary Research Institute, Vom 930103, Plateau State, Nigeria
| | | | - Yakubu Joel Atuman
- National Veterinary Research Institute, Vom 930103, Plateau State, Nigeria
| | - Tirumala Bharani Kumar Settypalli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria
| | - Charles Euloge Lamien
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria
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Haegeman A, De Leeuw I, Philips W, De Regge N. Development and Validation of a New DIVA Real-Time PCR Allowing to Differentiate Wild-Type Lumpy Skin Disease Virus Strains, Including the Asian Recombinant Strains, from Neethling-Based Vaccine Strains. Viruses 2023; 15:v15040870. [PMID: 37112850 PMCID: PMC10146157 DOI: 10.3390/v15040870] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/09/2023] [Accepted: 03/24/2023] [Indexed: 03/31/2023] Open
Abstract
The current epidemic in Asia, driven by LSDV recombinants, poses difficulties to existing DIVA PCR tests, as these do not differentiate between homologous vaccine strains and the recombinant strains. We, therefore, developed and validated a new duplex real-time PCR capable of differentiating Neethling-based vaccine strains from classical and recombinant wild-type strains that are currently circulating in Asia. The DIVA potential of this new assay, seen in the in silico evaluation, was confirmed on samples from LSDV infected and vaccinated animals and on isolates of LSDV recombinants (n = 12), vaccine (n = 5), and classic wild-type strains (n = 6). No cross-reactivity or a-specificity with other capripox viruses was observed under field conditions in non-capripox viral stocks and negative animals. The high analytical sensitivity is translated into a high diagnostic specificity as more than 70 samples were all correctly detected with Ct values very similar to those of a published first-line pan capripox real-time PCR. Finally, the low inter- and intra-run variability observed shows that the new DIVA PCR is very robust which facilitates its implementation in the lab. All validation parameters that are mentioned above indicate the potential of the newly developed test as a promising diagnostic tool which could help to control the current LSDV epidemic in Asia.
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Affiliation(s)
- Andy Haegeman
- Sciensano, Infectious Diseases in Animals, Exotic and Vector-Borne Diseases, Groeselenberg 99, B-1180 Brussels, Belgium
- Correspondence:
| | - Ilse De Leeuw
- Sciensano, Infectious Diseases in Animals, Exotic and Vector-Borne Diseases, Groeselenberg 99, B-1180 Brussels, Belgium
| | - Wannes Philips
- Sciensano, EURL for Diseases Caused by Capripox Viruses, Groeselenberg 99, B-1180 Brussels, Belgium
| | - Nick De Regge
- Sciensano, Infectious Diseases in Animals, Exotic and Vector-Borne Diseases, Groeselenberg 99, B-1180 Brussels, Belgium
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Haegeman A, De Leeuw I, Mostin L, Van Campe W, Philips W, Elharrak M, De Regge N, De Clercq K. Duration of Immunity Induced after Vaccination of Cattle with a Live Attenuated or Inactivated Lumpy Skin Disease Virus Vaccine. Microorganisms 2023; 11. [PMID: 36677502 DOI: 10.3390/microorganisms11010210] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/18/2023] Open
Abstract
Vaccines have proven themselves as an efficient way to control and eradicate lumpy skin disease (LSD). In addition to the safety and efficacy aspects, it is important to know the duration for which the vaccines confer protective immunity, as this impacts the design of an efficient control and eradication program. We evaluated the duration of immunity induced by a live attenuated vaccine (LSDV LAV) and an inactivated vaccine (LSDV Inac), both based on LSDV. Cattle were vaccinated and challenged after 6, 12 and 18 months for LSDV LAV or after 6 and 12 months for the LSDV Inac. The LSDV LAV elicited a strong immune response and protection for up to 18 months, as no clinical signs or viremia could be observed after a viral LSDV challenge in any of the vaccinated animals. A good immune response and protection were similarly seen for the LSDV Inac after 6 months. However, two animals developed clinical signs and viremia when challenged after 12 months. In conclusion, our data support the annual booster vaccination when using the live attenuated vaccine, as recommended by the manufacturer, which could potentially even be prolonged. In contrast, a bi-annual vaccination seems necessary when using the inactivated vaccine.
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Liao K, Peng W, Qian B, Nan W, Shan Y, Zeng D, Tang F, Wu X, Chen Y, Xue F, Dai J. A highly adaptable platform powered by CRISPR-Cas12a to diagnose lumpy skin disease in cattle. Anal Chim Acta 2022; 1221:340079. [PMID: 35934339 DOI: 10.1016/j.aca.2022.340079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 05/19/2022] [Accepted: 06/09/2022] [Indexed: 12/24/2022]
Abstract
Lumpy skin disease (LSD) in cattle, a transboundary viral disease of cattle once restricted to Africa, has been spreading to many European and Asian countries in the past decade with huge economic losses. This emerging worldwide threat to cattle warrants the development of diagnostic methods for accurate disease screening of suspected samples to effectively control the spread of LSD. In this study, we integrated pre-amplification and three kinds of sensor systems with CRISPR and therefore established an LSD diagnosis platform with highly adaptable and ultra-sensitive advantages. It was the first CRISPR-powered platform that could identify lumpy skin disease virus from vaccine strains of goat pox virus and sheep pox virus. Its limit of detection (LOD) was one copy/reaction after introducing PCR or recombinase-aided amplification (RAA). Moreover, this platform achieved a satisfactory overall agreement in clinical diagnoses of 50 samples and its reproducibility and accuracy were superior to other qPCR methods we tested. The whole diagnostic procedure, from DNA extraction to the results, could complete in 5 h with a total cost of 1.7-9.6 $/test. Overall, this CRISPR-powered platform provided a novel diagnostic tool for portable, ultra-sensitive, rapid, and highly adaptable disease screening of LSD and may be an effective method to control this transboundary disease's spread.
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Affiliation(s)
- Kai Liao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wanqing Peng
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Bingxu Qian
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wenlong Nan
- Laboratory of Diagnostics Development, China Animal Health and Epidemiology Center, 369 Nanjing Road, Qingdao, Shandong, 266032, China
| | - Yuping Shan
- Lianyungang Animal Husbandry and Veterinary Station, Lianyungang, Jiangsu, 222003, China
| | - Dexin Zeng
- Technology Center of Hefei Customs, Hefei, 230022, China
| | - Fang Tang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiaodong Wu
- Laboratory of Diagnostics Development, China Animal Health and Epidemiology Center, 369 Nanjing Road, Qingdao, Shandong, 266032, China
| | - Yiping Chen
- Laboratory of Diagnostics Development, China Animal Health and Epidemiology Center, 369 Nanjing Road, Qingdao, Shandong, 266032, China.
| | - Feng Xue
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Jianjun Dai
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; China Pharmaceutical University, Nanjing, 211198, China
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Mathijs E, Haegeman A, De Clercq K, Van Borm S, Vandenbussche F. A robust, cost-effective and widely applicable whole-genome sequencing protocol for capripoxviruses. J Virol Methods 2022; 301:114464. [PMID: 35032481 PMCID: PMC8872832 DOI: 10.1016/j.jviromet.2022.114464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 12/22/2022]
Abstract
Robust method for the genomic characterization of all Capripoxviruses. Pre-sequencing enrichment method based on targeted long-range PCR amplification. Method applicable to low titre samples such as blood samples and vaccine batches. Viral DNA enrichment compatible with various sample types and sequencing platforms. Complete coding genome sequencing evaluated on three different sequencing platforms.
The diseases caused by capripoxviruses (CaPVs) are of major economic concern in sheep, goat and cattle as they are inexorably spreading into non-endemic regions. As CaPV strains are serologically indistinguishable and genetically highly homologous, typing closely related strains can only be achieved by whole genome sequencing. Unfortunately the number of publicly available genomes remains low as most sequencing methods rely on virus isolation. Therefore, we developed a robust, cost-effective and widely applicable method that allows to generate (nearly) complete CaPV genomes directly from clinical samples or commercial vaccine batches. A set of pan-CaPVs long-range PCRs spanning the entire genome was designed to generate PCR amplicons that can be sequenced on commonly used high-throughput sequencing platforms: MiSeq (Illumina), RSII (PacBio) and MinION (Oxford Nanopore Technologies). The robustness of the LR-PCR strategy was evaluated for all 3 members of CaPV directly from a variety of samples, including clinical samples (N = 7), vaccine batches (N = 6), and virus isolates (N = 2). The sequencing method described here allows to reconstruct (nearly) complete CaPV genomes in less than a week and will aid researchers studying closely-related CaPV strains worldwide.
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Affiliation(s)
- Elisabeth Mathijs
- Infectious Diseases in Animals, Sciensano, Rue Juliette Wytsmanstraat 14, 1050, Brussels, Belgium.
| | - Andy Haegeman
- Infectious Diseases in Animals, Sciensano, Rue Juliette Wytsmanstraat 14, 1050, Brussels, Belgium
| | - Kris De Clercq
- Infectious Diseases in Animals, Sciensano, Rue Juliette Wytsmanstraat 14, 1050, Brussels, Belgium
| | - Steven Van Borm
- Infectious Diseases in Animals, Sciensano, Rue Juliette Wytsmanstraat 14, 1050, Brussels, Belgium
| | - Frank Vandenbussche
- Infectious Diseases in Animals, Sciensano, Rue Juliette Wytsmanstraat 14, 1050, Brussels, Belgium
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Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin‐Bastuji B, Gonzales Rojas JL, Gortázar Schmidt C, Herskin M, Michel V, Miranda Chueca MÁ, Padalino B, Pasquali P, Sihvonen LH, Spoolder H, Ståhl K, Velarde A, Viltrop A, Winckler C, De Clercq K, Gubbins S, Klement E, Stegeman JA, Antoniou S, Aznar I, Broglia A, Van der Stede Y, Zancanaro G, Roberts HC. Assessment of the control measures for category A diseases of Animal Health Law: Lumpy Skin Disease. EFSA J 2022; 20:e07121. [PMID: 35106095 PMCID: PMC8784982 DOI: 10.2903/j.efsa.2022.7121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
EFSA received a mandate from the EC to assess the effectiveness of some of the control measures against diseases included in the Category A list according to Regulation (EU) 2016/429 on transmissible animal diseases ('Animal Health Law'). This opinion belongs to a series of opinions where these control measures are assessed, with this opinion covering the assessment of control measures for Lumpy Skin Disease (LSD). In this opinion, EFSA and the AHAW Panel of experts review the effectiveness of: i) clinical and laboratory sampling procedures, ii) monitoring period and iii) the minimum radius of the protection and surveillance zones, and the minimum length of time that measures should be applied in these zones. The general methodology used for this series of opinions has been published elsewhere; nonetheless, the transmission kernels used for the assessment of the minimum radius of the protection and surveillance zones are shown. Several scenarios for which these control measures had to be assessed were designed and agreed prior to the start of the assessment. The monitoring period was assessed as effective, and based on the transmission kernels available, it was concluded that the protection zone of 20 km radius and the surveillance zone of 50 km radius would comprise > 99% of the transmission from an affected establishment if transmission occurred. Recommendations provided for each of the assessed scenarios aim to support the European Commission in the drafting of further pieces of legislation, as well as for plausible ad hoc requests in relation to LSD.
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Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin-Bastuji B, Gonzales Rojas JL, Gortázar C, Herskin M, Michel V, Miranda Chueca MÁ, Padalino B, Pasquali P, Sihvonen LH, Spoolder H, Ståhl K, Velarde A, Viltrop A, Winckler C, De Clercq K, Gubbins S, Aznar I, Broglia A. Assessment of the control measures of the category A diseases of Animal Health Law: sheep and goat pox. EFSA J 2021; 19:e06933. [PMID: 34963791 PMCID: PMC8711069 DOI: 10.2903/j.efsa.2021.6933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
EFSA received a mandate from the European Commission to assess the effectiveness of some of the control measures against diseases included in the Category A list according to Regulation (EU) 2016/429 on transmissible animal diseases (‘Animal Health Law’). This opinion belongs to a series of opinions where these control measures will be assessed, with this opinion covering the assessment of control measures for sheep and goat pox. In this opinion, EFSA and the AHAW Panel of experts review the effectiveness of: (i) clinical and laboratory sampling procedures, (ii) monitoring period and (iii) the minimum radii of the protection and surveillance zones, and the minimum length of time the measures should be applied in these zones. The general methodology used for this series of opinions has been published elsewhere; nonetheless, the transmission kernels used for the assessment of the minimum radii of the protection and surveillance zones are shown. Several scenarios for which these control measures had to be assessed were designed and agreed prior to the start of the assessment. Different risk‐based sampling procedures based on clinical visits and laboratory testing are assessed in case of outbreak suspicion, granting animal movements and for repopulation purposes. The monitoring period of 21 days was assessed as effective. The estimated probability of transmission beyond the protection zone of 3 km radius from an infectious establishment is 9.6% (95% CI: 3.1–25.8%) and 2.3% (95% CI: 1–5.5%) for the surveillance zone of 10 km radius. This may be considered sufficient to contain the disease spread (95% probability of containing transmission corresponds to 5.3 Km). To contain 99% of the spread, the radius should be increased to 19.4 km (95% CI: 9.8–26.8). This may increase the number of farms in the surveillance zone, since the area would increase fourfold.
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Agianniotaki EI, Chaintoutis SC, Haegeman A, De Clercq K, Chondrokouki E, Dovas CI. A TaqMan probe-based multiplex real-time PCR method for the specific detection of wild type lumpy skin disease virus with beta-actin as internal amplification control. Mol Cell Probes 2021; 60:101778. [PMID: 34774743 DOI: 10.1016/j.mcp.2021.101778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/22/2021] [Accepted: 11/09/2021] [Indexed: 11/28/2022]
Abstract
Lumpy skin disease (LSD) is a transboundary disease of economic importance affecting cattle and buffaloes. In South-Eastern Europe, immunization of cattle with homologous live attenuated vaccines for LSD control has prevented outbreaks since 2017, but has been associated with adverse reactions resembling disease symptoms. Thus, a diagnostic method suitable for disease surveillance in farms during vaccination campaigns with Neethling (Onderstepoort) and SIS type (Lumpyvax) live attenuated LSDV vaccines in Europe should be able to detect the wild type (WT) LSDV in animals with adverse reactions to the vaccines and samples with potentially high titers of the vaccine LSDV. To this end, a real-time PCR method targeting the EEV gene of LSDV was developed for the specific detection of WT strains, along with the use of beta-actin gene as an internal amplification control (IAC). Amplification efficiency of the WT virus target was 99.0% and 98.6%, in the presence and in the absence of high loads of vaccine LSDV, respectively. In the presence of 105.6 vaccine LSDV DNA copies, the limit of detection for WT LSDV was 12.6 DNA copies per reaction. The inter-assay CV was 0.04% for WT LSDV and 0.13% for beta-actin. The method can confirm diagnosis in suspect cases irrespective of the presence of the vaccine LSDV DNA by overcoming the masking effect of the WT LSDV. The simultaneous amplification of the beta-actin gene further assures the quality of diagnostic testing. The new method is a surveillance tool, complementing the DIVA real-time PCR during vaccination campaigns and can provide rapid insight on the targeted EEV gene in countries with novel and recombinant LSDV strains.
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Affiliation(s)
- Eirini I Agianniotaki
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece; National Reference Laboratory for Capripoxviruses, Department of Molecular Diagnostics, FMD, Virological, Rickettsial & Exotic Diseases, Directorate of Athens Veterinary Center, Ministry of Rural Development and Food, Athens, Greece
| | - Serafeim C Chaintoutis
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Andy Haegeman
- Exotic Viruses and Particular Diseases Unit, Sciensano, Ukkel, Belgium
| | - Kris De Clercq
- Exotic Viruses and Particular Diseases Unit, Sciensano, Ukkel, Belgium
| | - Eleni Chondrokouki
- National Reference Laboratory for Capripoxviruses, Department of Molecular Diagnostics, FMD, Virological, Rickettsial & Exotic Diseases, Directorate of Athens Veterinary Center, Ministry of Rural Development and Food, Athens, Greece
| | - Chrysostomos I Dovas
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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11
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Aerts L, Haegeman A, De Leeuw I, Philips W, Van Campe W, Behaeghel I, Mostin L, De Clercq K. Detection of Clinical and Subclinical Lumpy Skin Disease Using Ear Notch Testing and Skin Biopsies. Microorganisms 2021; 9:2171. [PMID: 34683492 DOI: 10.3390/microorganisms9102171] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/28/2021] [Accepted: 10/15/2021] [Indexed: 11/16/2022] Open
Abstract
Lumpy skin disease (LSD) diagnosis is primarily based on clinical surveillance complemented by PCR of lesion crusts or nodule biopsies. Since LSD can be subclinical, the sensitivity of clinical surveillance could be lower than expected. Furthermore, real-time PCR for the detection of LSD viral DNA in blood samples from subclinical animals is only intermittently positive. Therefore, this study aimed to investigate an acceptable, easily applicable and more sensitive testing method for the detection of clinical and subclinical LSD. An animal experiment was conducted to investigate ear notches and biopsies from unaffected skin taken from the neck and dorsal back as alternatives to blood samples. It was concluded that for early LSD confirmation, normal skin biopsies and ear notches are less fit for purpose, as LSDV DNA is only detectable in these samples several days after it is detectable in blood samples. On the other hand, blood samples are less advisable for the detection of subclinical animals, while ear notches and biopsies were positive for LSD viral DNA in all subclinically infected animals by 16 days post infection. In conclusion, ear notches could be used for surveillance to detect subclinical animals after removing the clinical animals from a herd, to regain trade by substantiating the freedom of disease or to support research on LSDV transmission from subclinical animals.
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12
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Haegeman A, De Leeuw I, Saduakassova M, Van Campe W, Aerts L, Philips W, Sultanov A, Mostin L, De Clercq K. The Importance of Quality Control of LSDV Live Attenuated Vaccines for Its Safe Application in the Field. Vaccines (Basel) 2021; 9:1019. [PMID: 34579256 DOI: 10.3390/vaccines9091019] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/03/2021] [Accepted: 09/09/2021] [Indexed: 01/25/2023] Open
Abstract
Vaccination is an effective approach to prevent, control and eradicate diseases, including lumpy skin disease (LSD). One of the measures to address farmer hesitation to vaccinate is guaranteeing the quality of vaccine batches. The purpose of this study was to demonstrate the importance of a quality procedure via the evaluation of the LSD vaccine, Lumpivax (Kevevapi). The initial PCR screening revealed the presence of wild type LSD virus (LSDV) and goatpox virus (GTPV), in addition to vaccine LSDV. New phylogenetic PCRs were developed to characterize in detail the genomic content and a vaccination/challenge trial was conducted to evaluate the impact on efficacy and diagnostics. The characterization confirmed the presence of LSDV wild-, vaccine- and GTPV-like sequences in the vaccine vial and also in samples taken from the vaccinated animals. The analysis was also suggestive for the presence of GTPV-LSDV (vaccine/wild) recombinants. In addition, the LSDV status of some of the animal samples was greatly influenced by the differentiating real-PCR used and could result in misinterpretation. Although the vaccine was clinically protective, the viral genomic content of the vaccine (being it multiple Capripox viruses and/or recombinants) and the impact on the diagnostics casts serious doubts of its use in the field.
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13
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Vidanović D, Tešović B, Šekler M, Debeljak Z, Vasković N, Matović K, Koltsov A, Krstevski K, Petrović T, De Leeuw I, Haegeman A. Validation of TaqMan-Based Assays for Specific Detection and Differentiation of Wild-Type and Neethling Vaccine Strains of LSDV. Microorganisms 2021; 9:microorganisms9061234. [PMID: 34204157 PMCID: PMC8229051 DOI: 10.3390/microorganisms9061234] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/25/2021] [Accepted: 05/29/2021] [Indexed: 11/16/2022] Open
Abstract
Lumpy skin disease (LSD) is an important animal disease with significant health and economic impacts. It is considered a notifiable disease by the OIE. Attenuated strains of LSDV have been successfully used as vaccines (LAV) but can also produce mild or systemic reactions. Vaccination campaigns using LAVs are therefore only viable if accompanying DIVA assays are available. Two DIVA qPCR assays able to distinguish Neethling-based LAVs and wild-type LSDV were developed. Upon validation, both assays were shown to have high sensitivity and specificity with a diagnostic performance comparable to other published DIVA assays. This confirmed their potential as reliable tools to confirm infection in animals during vaccination campaigns based on Neethling vaccine strains.
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Affiliation(s)
- Dejan Vidanović
- Veterinary Specialized Institute Kraljevo, 36000 Kraljevo, Serbia; (B.T.); (M.Š.); (Z.D.); (N.V.); (K.M.)
- Correspondence: ; Tel.: +381-648247533
| | - Bojana Tešović
- Veterinary Specialized Institute Kraljevo, 36000 Kraljevo, Serbia; (B.T.); (M.Š.); (Z.D.); (N.V.); (K.M.)
| | - Milanko Šekler
- Veterinary Specialized Institute Kraljevo, 36000 Kraljevo, Serbia; (B.T.); (M.Š.); (Z.D.); (N.V.); (K.M.)
| | - Zoran Debeljak
- Veterinary Specialized Institute Kraljevo, 36000 Kraljevo, Serbia; (B.T.); (M.Š.); (Z.D.); (N.V.); (K.M.)
| | - Nikola Vasković
- Veterinary Specialized Institute Kraljevo, 36000 Kraljevo, Serbia; (B.T.); (M.Š.); (Z.D.); (N.V.); (K.M.)
| | - Kazimir Matović
- Veterinary Specialized Institute Kraljevo, 36000 Kraljevo, Serbia; (B.T.); (M.Š.); (Z.D.); (N.V.); (K.M.)
| | - Andrey Koltsov
- Federal Research Center of Virology and Microbiology, 601125 Pokrov, Russia;
| | - Kiril Krstevski
- Faculty of Veterinary Medicine, University Ss Cyril and Methodius in Skopje, 1000 Skopje, North Macedonia;
| | - Tamaš Petrović
- Scientific Veterinary Institute Novi Sad, 21000 Novi Sad, Serbia;
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14
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Haegeman A, De Leeuw I, Mostin L, Campe WV, Aerts L, Venter E, Tuppurainen E, Saegerman C, De Clercq K. Comparative Evaluation of Lumpy Skin Disease Virus-Based Live Attenuated Vaccines. Vaccines (Basel) 2021; 9:vaccines9050473. [PMID: 34066658 PMCID: PMC8151199 DOI: 10.3390/vaccines9050473] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/28/2021] [Accepted: 05/03/2021] [Indexed: 11/21/2022] Open
Abstract
Vaccines form the cornerstone of any control, eradication and preventative strategy and this is no different for lumpy skin disease. However, the usefulness of a vaccine is determined by a multiplicity of factors which include stability, efficiency, safety and ease of use, to name a few. Although the vaccination campaign in the Balkans against lumpy skin disease virus (LSDV) was successful and has been implemented with success in the past in other countries, data of vaccine failure have also been reported. It was therefore the purpose of this study to compare five homologous live attenuated LSDV vaccines (LSDV LAV) in a standardized setting. All five LSDV LAVs studied were able to protect against a challenge with virulent LSDV. Aside from small differences in serological responses, important differences were seen in side effects such as a local reaction and a Neethling response upon vaccination between the analyzed vaccines. These observations can have important implications in the applicability in the field for some of these LSDV LAVs.
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Affiliation(s)
- Andy Haegeman
- Infectious Diseases in Animals, Exotic and Particular Diseases, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium; (I.D.L.); (K.D.C.)
- Correspondence:
| | - Ilse De Leeuw
- Infectious Diseases in Animals, Exotic and Particular Diseases, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium; (I.D.L.); (K.D.C.)
| | - Laurent Mostin
- Experimental Center Machelen, Sciensano, Kerklaan 68, B-1830 Machelen, Belgium; (L.M.); (W.V.C.)
| | - Willem Van Campe
- Experimental Center Machelen, Sciensano, Kerklaan 68, B-1830 Machelen, Belgium; (L.M.); (W.V.C.)
| | - Laetitia Aerts
- EURL for Diseases Caused by Capripox Viruses, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium;
| | - Estelle Venter
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa;
- College of Public Health, Medical and Veterinary Sciences, Discipline: Veterinary Science, James Cook University, Townsville, QLD 4811, Australia
| | - Eeva Tuppurainen
- Institut für Internationale Tiergesundheit/One Health, Friedrich-Loeffler-Institut Federal Research Institute for Animal Health, 17489 Greifswald-Insel Riems, Germany;
| | - Claude Saegerman
- Fundamental and Applied Research for Animals & Health (FARAH) Center, Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiège), Faculty of Veterinary Medicine, University of Liege, 4000 Liege, Belgium;
| | - Kris De Clercq
- Infectious Diseases in Animals, Exotic and Particular Diseases, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium; (I.D.L.); (K.D.C.)
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15
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Wolff J, Beer M, Hoffmann B. Probe-Based Real-Time qPCR Assays for a Reliable Differentiation of Capripox Virus Species. Microorganisms 2021; 9:microorganisms9040765. [PMID: 33917525 PMCID: PMC8067474 DOI: 10.3390/microorganisms9040765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 11/30/2022] Open
Abstract
Outbreaks of the three capripox virus species, namely lumpy skin disease virus, sheeppox virus, and goatpox virus, severely affect animal health and both national and international economies. Therefore, the World Organization for Animal Health (OIE) classified them as notifiable diseases. Until now, discrimination of capripox virus species was possible by using different conventional PCR protocols. However, more sophisticated probe-based real-time qPCR systems addressing this issue are, to our knowledge, still missing. In the present study, we developed several duplex qPCR assays consisting of different types of fluorescence-labelled probes that are highly sensitive and show a high analytical specificity. Finally, our assays were combined with already published diagnostic methods to a diagnostic workflow that enables time-saving, reliable, and robust detection, differentiation, and characterization of capripox virus isolates.
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16
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Badhy SC, Chowdhury MGA, Settypalli TBK, Cattoli G, Lamien CE, Fakir MAU, Akter S, Osmani MG, Talukdar F, Begum N, Khan IA, Rashid MB, Sadekuzzaman M. Molecular characterization of lumpy skin disease virus (LSDV) emerged in Bangladesh reveals unique genetic features compared to contemporary field strains. BMC Vet Res 2021; 17:61. [PMID: 33514360 PMCID: PMC7844896 DOI: 10.1186/s12917-021-02751-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/08/2021] [Indexed: 11/23/2022] Open
Abstract
Background Lumpy skin disease (LSD) is a contagious viral disease of cattle caused by lumpy skin disease virus (LSDV). LSD has recently spread in Asia following outbreaks in the Middle East and Europe. The disease emerged in Bangladesh in July 2019 in the Chattogram district, then rapidly spread throughout the entire country. We investigated six LSD outbreaks in Bangladesh to record the clinical signs and collect samples for diagnostic confirmation. Furthermore, we performed the molecular characterization of Bangladesh isolates, analyzing the full RPO30 and GPCR genes and the partial EEV glycoprotein gene. Results Clinical observations revealed common LSD clinical signs in the affected cattle. PCR and real-time PCR, showed the presence of the LSDV genome in samples from all six districts. Phylogenetic analysis and detailed inspection of multiple sequence alignments revealed that Bangladesh isolates differ from common LSDV field isolates encountered in Africa, the Middle East, and Europe, as well as newly emerged LSDV variants in Russia and China. Instead, they were closely related to LSDV KSGP-0240, LSDV NI2490, and LSDV Kenya. Conclusions These results show the importance of continuous monitoring and characterization of circulating strains and the need to continually refine the strategies for differentiating vaccine strains from field viruses. Supplementary Information The online version contains supplementary material available at 10.1186/s12917-021-02751-x.
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Affiliation(s)
- Shukes Chandra Badhy
- Central Disease Investigation Laboratory (CDIL), 48, KaziAlauddin Road, Dhaka, People's Republic of Bangladesh.,Department of Livestock Services, Dhaka, People's Republic of Bangladesh
| | - Mohammad Golam Azam Chowdhury
- Central Disease Investigation Laboratory (CDIL), 48, KaziAlauddin Road, Dhaka, People's Republic of Bangladesh.,Department of Livestock Services, Dhaka, People's Republic of Bangladesh
| | - Tirumala Bharani Kumar Settypalli
- Animal Production and Health Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Wagramer Strasse 5, P.O. Box 100, A-1400, Vienna, Austria
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Wagramer Strasse 5, P.O. Box 100, A-1400, Vienna, Austria
| | - Charles Euloge Lamien
- Animal Production and Health Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Wagramer Strasse 5, P.O. Box 100, A-1400, Vienna, Austria
| | - Mohammad Aflak Uddin Fakir
- Central Disease Investigation Laboratory (CDIL), 48, KaziAlauddin Road, Dhaka, People's Republic of Bangladesh.,Department of Livestock Services, Dhaka, People's Republic of Bangladesh
| | - Shamima Akter
- Central Disease Investigation Laboratory (CDIL), 48, KaziAlauddin Road, Dhaka, People's Republic of Bangladesh.,Department of Livestock Services, Dhaka, People's Republic of Bangladesh
| | | | - Faisol Talukdar
- Department of Livestock Services, Dhaka, People's Republic of Bangladesh
| | - Noorjahan Begum
- Department of Livestock Services, Dhaka, People's Republic of Bangladesh
| | - Izhar Ahmed Khan
- Central Disease Investigation Laboratory (CDIL), 48, KaziAlauddin Road, Dhaka, People's Republic of Bangladesh.,Department of Livestock Services, Dhaka, People's Republic of Bangladesh
| | - Md Bazlur Rashid
- Central Disease Investigation Laboratory (CDIL), 48, KaziAlauddin Road, Dhaka, People's Republic of Bangladesh.,Department of Livestock Services, Dhaka, People's Republic of Bangladesh
| | - Mohammad Sadekuzzaman
- Central Disease Investigation Laboratory (CDIL), 48, KaziAlauddin Road, Dhaka, People's Republic of Bangladesh. .,Department of Livestock Services, Dhaka, People's Republic of Bangladesh.
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17
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Sohier C, Haegeman A, Mostin L, De Leeuw I, Campe WV, De Vleeschauwer A, Tuppurainen ESM, van den Berg T, De Regge N, De Clercq K. Experimental evidence of mechanical lumpy skin disease virus transmission by Stomoxys calcitrans biting flies and Haematopota spp. horseflies. Sci Rep 2019; 9:20076. [PMID: 31882819 DOI: 10.1038/s41598-019-56605-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/11/2019] [Indexed: 11/15/2022] Open
Abstract
Lumpy skin disease (LSD) is a devastating disease of cattle characterized by fever, nodules on the skin, lymphadenopathy and milk drop. Several haematophagous arthropod species like dipterans and ticks are suspected to play a role in the transmission of LSDV. Few conclusive data are however available on the importance of biting flies and horseflies as potential vectors in LSDV transmission. Therefore an in vivo transmission study was carried out to investigate possible LSDV transmission by Stomoxys calcitrans biting flies and Haematopota spp. horseflies from experimentally infected viraemic donor bulls to acceptor bulls. LSDV transmission by Stomoxys calcitrans was evidenced in 3 independent experiments, LSDV transmission by Haematopota spp. was shown in one experiment. Evidence of LSD was supported by induction of nodules and virus detection in the blood of acceptor animals. Our results are supportive for a mechanical transmission of the virus by these vectors.
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18
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Haegeman A, De Leeuw I, Mostin L, Van Campe W, Aerts L, Vastag M, De Clercq K. An Immunoperoxidase Monolayer Assay (IPMA) for the detection of lumpy skin disease antibodies. J Virol Methods 2019; 277:113800. [PMID: 31837373 PMCID: PMC6996284 DOI: 10.1016/j.jviromet.2019.113800] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/14/2019] [Accepted: 12/10/2019] [Indexed: 12/01/2022]
Abstract
A new immunoperoxidase monolayer assay (IPMA) was developed to detect LSDV antibodies. The new test is highly specific and sensitive and is suitable for medium throughput. LSDV-IPMA detected the antibodies earlier than the VNT and a commercial ELISA. The LSDV-IPMA system is easily adapted for SPPV and GPV.
During this study a new Immunoperoxidase Monolayer Assay (IPMA) was developed for the detection of antibodies against lumpy skin disease virus (LSDV) in an easy and low tech setting. Using two dilutions (1:50 and 1:300) in a duplicate format, the test was shown to be highly sensitive, specific and repeatable. In comparison to the VNT and a commercial ELISA, the LSDV-IPMA was able to detect the LSDV antibodies earlier in infected, vaccinated and vaccinated/infected animals. The assay is very flexible as it can be easily adapted for the detection of sheeppox or goatpox antibodies and it can be scaled-up to handle medium size sample sets by preparing the IPMA plates in advance. These plates are safe and can be handled in low biosafety level labs.
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Affiliation(s)
- Andy Haegeman
- Sciensano, Infectious Diseases in Animals, Exotic and Particular Diseases, Groeselenberg 99, B-1180, Brussels, Belgium.
| | - Ilse De Leeuw
- Sciensano, Infectious Diseases in Animals, Exotic and Particular Diseases, Groeselenberg 99, B-1180, Brussels, Belgium.
| | - Laurent Mostin
- Sciensano, Experimental Center Machelen, Kerklaan 68, B-1830, Machelen, Belgium.
| | - Willem Van Campe
- Sciensano, Experimental Center Machelen, Kerklaan 68, B-1830, Machelen, Belgium.
| | - Laetitia Aerts
- EURL for Diseases Caused by Capripox Viruses, Sciensano, Groeselenberg 99, B-1180, Brussels, Belgium.
| | - Maria Vastag
- Sciensano, Infectious Diseases in Animals, Exotic and Particular Diseases, Groeselenberg 99, B-1180, Brussels, Belgium.
| | - Kris De Clercq
- Sciensano, Infectious Diseases in Animals, Exotic and Particular Diseases, Groeselenberg 99, B-1180, Brussels, Belgium.
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19
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Haegeman A, De Vleeschauwer A, De Leeuw I, Vidanović D, Šekler M, Petrović T, Demarez C, Lefebvre D, De Clercq K. Overview of diagnostic tools for Capripox virus infections. Prev Vet Med 2019; 181:104704. [PMID: 31196699 DOI: 10.1016/j.prevetmed.2019.104704] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 01/29/2019] [Accepted: 03/13/2019] [Indexed: 01/06/2023]
Abstract
Capripox viruses are the causative agents of important animal diseases in cattle (Lumpy Skin Disease), sheep (Sheeppox) and goats (Goatpox) with severe socio-economic impact in case of wide scale outbreaks. Therefore there is a constant need for adequate diagnostic tools. The assays must be fit-for-purpose to identify the virus quickly and correctly and to be useful for surveillance and monitoring at different stages of an epidemic. Different diagnostic performance characteristics are required depending on the situation and the test purpose. The need for high throughput, high specificity/sensitivity and the capability for differentiating field virus strains from vaccine strains drives the development of new and better assays preferably with an advantageous cost-benefit balance. This review aims to look at existing and new virological and serological diagnostic tools used in the control against diseases caused by Capripox viruses.
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Affiliation(s)
- Andy Haegeman
- Sciensano, Exotic and Particular Diseases, Groeselenberg 99, 1180, Ukkel, Belgium.
| | | | - Ilse De Leeuw
- Sciensano, Exotic and Particular Diseases, Groeselenberg 99, 1180, Ukkel, Belgium.
| | - Dejan Vidanović
- Specialized Veterinary Institute "Kraljevo", Kraljevo, Serbia.
| | - Milanko Šekler
- Specialized Veterinary Institute "Kraljevo", Kraljevo, Serbia.
| | - Tamaš Petrović
- Department for Virology, Scientific Veterinary Institute "Novi Sad", Novi Sad, Serbia.
| | - Céline Demarez
- Sciensano, Exotic and Particular Diseases, Groeselenberg 99, 1180, Ukkel, Belgium.
| | - David Lefebvre
- Sciensano, Exotic and Particular Diseases, Groeselenberg 99, 1180, Ukkel, Belgium.
| | - Kris De Clercq
- Sciensano, Exotic and Particular Diseases, Groeselenberg 99, 1180, Ukkel, Belgium.
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20
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Calistri P, DeClercq K, De Vleeschauwer A, Gubbins S, Klement E, Stegeman A, Cortiñas Abrahantes J, Antoniou SE, Broglia A, Gogin A. Lumpy skin disease: scientific and technical assistance on control and surveillance activities. EFSA J 2018; 16:e05452. [PMID: 32625728 PMCID: PMC7009741 DOI: 10.2903/j.efsa.2018.5452] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The duration of the vaccination campaign sufficient to eliminate lumpy skin disease (LSD) mainly depends on the vaccination effectiveness and coverage achieved. By using a spread epidemiological model, assuming a vaccination effectiveness of 65%, with 50% and 90% coverage, 4 and 3 years campaigns, respectively, are needed to eliminate LSD. When vaccination effectiveness is 80% to 95%, 2 years of vaccination at coverage of 90% is sufficient to eliminate LSD virus (LSDV). For shorter campaigns, LSD is predicted to persist. When the infection is eliminated by vaccination, two pathways for disease recurrence are possible, (i) by new introduction from a neighbouring affected area, especially by introduction of infected animals, or, less likely (ii) the infection persisting either in the environment, in vectors or in wild animals. For planning surveillance, several elements should be considered: the objectives and related design prevalence, the epidemiological situation, the immunological status of the host population, the geographical area and the season, the type of surveillance (active or passive), the diagnostic methods including clinical detection (considered the most effective method for early detection of LSD), the target population, the sample size and frequency. According to the model, for early detecting new introductions of LSD, it may be needed to clinically check a large number of herds (e.g. 2–3,000 herds) monthly. Lower sample sizes can be considered, when a greater delay in detecting the virus is acceptable. Where vaccination is maintained, active surveillance for verifying the effectiveness of vaccination would be needed. Demonstrating disease absence can rely on serological surveillance, which should consider the test sensitivity, the design prevalence (estimated value: 3.5%), the onset and duration of serum antibodies. Important knowledge gaps on LSD are about within‐herd transmission, duration of protective immunity, role of vectors, diagnostic tests, farm location and type in the at‐risk countries and the epidemiological status of neighbouring countries.
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21
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Agianniotaki EI, Chaintoutis SC, Haegeman A, Tasioudi KE, De Leeuw I, Katsoulos PD, Sachpatzidis A, De Clercq K, Alexandropoulos T, Polizopoulou ZS, Chondrokouki ED, Dovas CI. Development and validation of a TaqMan probe-based real-time PCR method for the differentiation of wild type lumpy skin disease virus from vaccine virus strains. J Virol Methods 2017; 249:48-57. [PMID: 28837841 DOI: 10.1016/j.jviromet.2017.08.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 07/24/2017] [Accepted: 08/16/2017] [Indexed: 10/19/2022]
Abstract
Lumpy skin disease (LSD) is a transboundary viral disease of cattle with severe economic impact. Immunization of cattle with homologous live attenuated vaccines poses a number of diagnostic problems, as it has been associated with adverse reactions resembling disease symptoms. The latter hampers clinical diagnosis and poses challenges in virus identification. To this end, a duplex quantitative real-time PCR method targeting the GPCR gene was developed and validated, for the concurrent detection and differentiation of wild type and vaccine Lumpy skin disease virus (LSDV) strains. The method was evaluated in three laboratories. The evaluation included a panel of 38 poxvirus isolates/strains and the analytical characteristics of the method were determined. Amplification efficiencies were 91.3% and 90.7%, for wild type and vaccine LSDV, respectively; the limit of detection was 8 DNA copies for both targets and the inter-assay CV was 0.30% for wild type and 0.73% for vaccine LSDV. The diagnostic performance was assessed using 163 LSDV-positive samples, including field specimens and samples from experimentally vaccinated/infected animals. The method is able to confirm diagnosis in suspect cases, it differentiates infected from vaccinated animals (DIVA) and can be regarded as an important tool for effective LSD surveillance and eradication during vaccination campaigns.
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Affiliation(s)
- Eirini I Agianniotaki
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece; National Reference Laboratory for CaPVs, Department of Molecular Diagnostics, FMD, Virological, Rickettsial & Exotic Diseases, Athens Veterinary Center, Ministry of Rural Development and Food, Athens, Greece
| | - Serafeim C Chaintoutis
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Andy Haegeman
- Unit Vesicular and Exotic Diseases, Veterinary and Agrochemical Research Centre (CODA-CERVA), Ukkel, Belgium
| | - Konstantia E Tasioudi
- National Reference Laboratory for CaPVs, Department of Molecular Diagnostics, FMD, Virological, Rickettsial & Exotic Diseases, Athens Veterinary Center, Ministry of Rural Development and Food, Athens, Greece
| | - Ilse De Leeuw
- Unit Vesicular and Exotic Diseases, Veterinary and Agrochemical Research Centre (CODA-CERVA), Ukkel, Belgium
| | - Panagiotis-Dimitrios Katsoulos
- Clinic of Farm Animals, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Kris De Clercq
- Unit Vesicular and Exotic Diseases, Veterinary and Agrochemical Research Centre (CODA-CERVA), Ukkel, Belgium
| | - Thomas Alexandropoulos
- Directorate General of Sustainable Animal Production and Veterinary Medicines, Ministry of Rural Development and Food, Athens, Greece
| | - Zoe S Polizopoulou
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Eleni D Chondrokouki
- National Reference Laboratory for CaPVs, Department of Molecular Diagnostics, FMD, Virological, Rickettsial & Exotic Diseases, Athens Veterinary Center, Ministry of Rural Development and Food, Athens, Greece
| | - Chrysostomos I Dovas
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Vidanović D, Šekler M, Petrović T, Debeljak Z, Vasković N, Matović K, Hoffmann B. Real-Time PCR Assays for the Specific Detection of Field Balkan Strains of Lumpy Skin Disease Virus. ACTA VET-BEOGRAD 2016. [DOI: 10.1515/acve-2016-0038] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Lumpy skin disease (LSD) is an important disease of cattle which is included in the OIE list of notifiable terrestrial animal diseases because of its great economic importance. The etiological agent is the Lumpy skin disease virus (LSDV).
In the control of LSD attenuated strains of LSDV and SPPV are successfully used as vaccine strains in infected areas. In the case of vaccination policy, due to the possibility of mild or systemic post-vaccination reactions in vaccinated animals, the application of diagnostic procedures that will rapidly and specifically differentiate LSDV field strains from LSD vaccine virus strains are extremely important. Rapidity in diagnostics and disposal of infected animals is one of the key factors in the prevention of spreading the disease.
In the presented study we have described the development and validation of two real-time TaqMan-PCR assays for a rapid, sensitive and specific detection of the virulent field LSDV strain currently circulating in the Balkan Peninsula. Specificity for the field strain and exclusivity for vaccine strains was tested on 171 samples from naturally infected and vaccinated animals.
The results of this study show that both developed real-time PCR assays are more sensitive than the conventional nested PCR in detecting field LSDV strains thus enabling rapid and high-throughput detection of animals infected with field strains of LSDV.
In conclusion, both KV-2 and FLI real-time PCR assays described in this study are simple, rapid, sensitive and suitable for routine use in a diagnostic laboratory and have the potential to replace conventional nested gel-based PCR assays as the standard procedure for the detection of field strains of LSDV in clinical samples.
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Affiliation(s)
- Dejan Vidanović
- Department for Laboratory Diagnostic, Veterinary Specialized Institute „Kraljevo“, Kraljevo, Serbia
| | - Milanko Šekler
- Department for Laboratory Diagnostic, Veterinary Specialized Institute „Kraljevo“, Kraljevo, Serbia
| | - Tamaš Petrović
- Virology Department, Scientific Veterinary Institute „Novi Sad“, Novi Sad, Serbia
| | - Zoran Debeljak
- Department for Laboratory Diagnostic, Veterinary Specialized Institute „Kraljevo“, Kraljevo, Serbia
| | - Nikola Vasković
- Department for Laboratory Diagnostic, Veterinary Specialized Institute „Kraljevo“, Kraljevo, Serbia
| | - Kazimir Matović
- Department for Laboratory Diagnostic, Veterinary Specialized Institute „Kraljevo“, Kraljevo, Serbia
| | - Bernd Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler Institut, Greifswald-Insel Riems, Germany
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Shalaby MA, El-Deeb A, El-Tholoth M, Hoffmann D, Czerny CP, Hufert FT, Weidmann M, Abd El Wahed A. Recombinase polymerase amplification assay for rapid detection of lumpy skin disease virus. BMC Vet Res 2016; 12:244. [PMID: 27806722 PMCID: PMC5094145 DOI: 10.1186/s12917-016-0875-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 10/28/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Lumpy skin disease virus (LSDV) is a Capripoxvirus infecting cattle and Buffalos. Lumpy skin disease (LSD) leads to significant economic losses due to hide damage, reduction of milk production, mastitis, infertility and mortalities (10 %). Early detection of the virus is crucial to start appropriate outbreak control measures. Veterinarians rely on the presence of the characteristic clinical signs of LSD. Laboratory diagnostics including virus isolation, sequencing and real-time polymerase chain reaction (PCR) are performed at well-equipped laboratories. In this study, a portable, simple, and rapid recombinase polymerase amplification (RPA) assay for the detection of LSDV-genome for the use on farms was developed. RESULTS The LSDV RPA assay was performed at 42 °C and detected down to 179 DNA copies/reaction in a maximum of 15 min. Unspecific amplification was observed with neither LSDV-negative samples (n = 12) nor nucleic acid preparations from orf virus, bovine papular stomatitis virus, cowpoxvirus, Peste des petits ruminants and Blue tongue virus (serotypes 1, 6 and 8). The clinical sensitivity of the LSDV RPA assay matched 100 % (n = 22) to real-time PCR results. In addition, the LSDV RPA assay detected sheep and goat poxviruses. CONCLUSION The LSDV RPA assay is a rapid and sensitive test that could be implemented in field or at quarantine stations for the identification of LSDV infected case.
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Affiliation(s)
- Mohamed A. Shalaby
- Virology Department, Faculty of Veterinary Medicine, Cairo University, 12211 Giza, Egypt
| | - Ayman El-Deeb
- Virology Department, Faculty of Veterinary Medicine, Cairo University, 12211 Giza, Egypt
| | - Mohamed El-Tholoth
- Virology Department, Faculty of Veterinary Medicine, Mansoura University, 35516 Mansoura, Egypt
| | - Donata Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute, 17493 Greifswald-Insel Riems, Germany
| | - Claus-Peter Czerny
- Division of Microbiology and Animal Hygiene, Department of Animal Sciences, Faculty of Agriculture Sciences, Georg-August-University, 37077 Goettingen, Germany
| | - Frank T. Hufert
- Institute of Microbiology & Virology, Brandenburg Medical School Fontane, 01968 Senftenberg, Germany
| | - Manfred Weidmann
- Institute of Aquaculture, University of Stirling, FK9 4LA Stirling, Scotland UK
| | - Ahmed Abd El Wahed
- Division of Microbiology and Animal Hygiene, Department of Animal Sciences, Faculty of Agriculture Sciences, Georg-August-University, 37077 Goettingen, Germany
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Vandenbussche F, Mathijs E, Lefebvre D, De Clercq K, Van Borm S. A Tale of Tails: Dissecting the Enhancing Effect of Tailed Primers in Real-Time PCR. PLoS One 2016; 11:e0164463. [PMID: 27723800 PMCID: PMC5056738 DOI: 10.1371/journal.pone.0164463] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 09/26/2016] [Indexed: 11/29/2022] Open
Abstract
Non-specific tail sequences are often added to the 5’-terminus of primers to improve the robustness and overall performance of diagnostic assays. Despite the widespread use of tailed primers, the underlying working mechanism is not well understood. To address this problem, we conducted a detailed in vitro and in silico analysis of the enhancing effect of primer tailing on 2 well-established foot-and-mouth disease virus (FMDV) RT-qPCR assays using an FMDV reference panel. Tailing of the panFMDV-5UTR primers mainly affected the shape of the amplification curves. Modelling of the raw fluorescence data suggested a reduction of the amplification efficiency due to the accumulation of inhibitors. In depth analysis of PCR products indeed revealed the rapid accumulation of forward-primer derived artefacts. More importantly, tailing of the forward primer delayed artefacts formation and concomitantly restored the sigmoidal shape of the amplification curves. Our analysis also showed that primer tailing can alter utilisation patterns of degenerate primers and increase the number of primer variants that are able to participate in the reaction. The impact of tailed primers was less pronounced in the panFMDV-3D assay with only 5 out of 50 isolates showing a clear shift in Cq values. Sequence analysis of the target region of these 5 isolates revealed several mutations in the inter-primer region that extend an existing hairpin structure immediately downstream of the forward primer binding site. Stabilisation of the forward primer with either a tail sequence or cationic spermine units restored the sensitivity of the assay, which suggests that the enhancing effect in the panFMDV-3D assay is due to a more efficient extension of the forward primer. ur results show that primer tailing can alter amplification through various mechanisms that are determined by both the assay and target region. These findings expand our understanding of primer tailing and should enable a more targeted and efficient use of tailed primers.
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Affiliation(s)
- Frank Vandenbussche
- Molecular Platform, Operational Directorate of Viral Diseases, CODA-CERVA, Brussels, Belgium
- * E-mail:
| | - Elisabeth Mathijs
- Molecular Platform, Operational Directorate of Viral Diseases, CODA-CERVA, Brussels, Belgium
| | - David Lefebvre
- Vesicular and Exotic Diseases, Operational Directorate of Viral Diseases, CODA-CERVA, Brussels, Belgium
| | - Kris De Clercq
- Vesicular and Exotic Diseases, Operational Directorate of Viral Diseases, CODA-CERVA, Brussels, Belgium
| | - Steven Van Borm
- Molecular Platform, Operational Directorate of Viral Diseases, CODA-CERVA, Brussels, Belgium
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Haegeman A, Zro K, Sammin D, Vandenbussche F, Ennaji MM, De Clercq K. Investigation of a Possible Link Between Vaccination and the 2010 Sheep Pox Epizootic in Morocco. Transbound Emerg Dis 2015; 63:e278-e287. [PMID: 25753969 DOI: 10.1111/tbed.12342] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Indexed: 11/28/2022]
Abstract
Sheep pox is endemic in most parts of Northern Africa and has the potential to cause severe economic problems. Live attenuated vaccines are used in Morocco, and in many other countries, to control the disease. Sheep pox virus (SPPV) re-appeared in 2010 causing a nodular clinical form previously not observed in Morocco. The severe clinical signs observed during the course of this outbreak and initial reports citing similarity in nucleotide sequence between the Moroccan vaccine strain and field isolates warranted a more in depth analysis of this epizootic. In this study, sequence analysis showed that isolates obtained from four provinces of eastern Morocco were identical, demonstrating that a single SPPV strain was responsible for the 2010 epizootic. In addition, the genome fragments sequenced and phylogenetic analyses undertaken as part of this study showed significant differences between field isolates and the Moroccan vaccine strain. New PCR methods were developed to differentiate between wild-type isolates and vaccine strains of SPPV. Using these methods, no trace of wild-type SPPV was found in the vaccine and no evidence was found to suggest that the vaccine strain was causing clinical disease.
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Affiliation(s)
- A Haegeman
- Viral Diseases, Vesicular and Exotic Diseases, CODA-CERVA, Brussels, Belgium.
| | - K Zro
- Laboratoire de Virologie et Hygiène & Microbiologie, Faculté des Sciences et Techniques, Mohammedia, Morocco.,Laboratoire de diagnostic recherche et développement, Biopharma, Rabat, Morocco
| | - D Sammin
- Department of Agriculture Food and the Marine Laboratories, Backweston, Co. Kildare, Ireland
| | - F Vandenbussche
- Viral Diseases, Molecular Platform, CODA-CERVA, Brussels, Belgium
| | - M M Ennaji
- Laboratoire de Virologie et Hygiène & Microbiologie, Faculté des Sciences et Techniques, Mohammedia, Morocco
| | - K De Clercq
- Viral Diseases, Vesicular and Exotic Diseases, CODA-CERVA, Brussels, Belgium
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