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Lee HS, Bui VN, Dao DT, Bui NA, Le TD, Kieu MA, Nguyen QH, Tran LH, Roh JH, So KM, Hur TY, Oh SI. Pathogenicity of an African swine fever virus strain isolated in Vietnam and alternative diagnostic specimens for early detection of viral infection. Porcine Health Manag 2021; 7:36. [PMID: 33934707 PMCID: PMC8091783 DOI: 10.1186/s40813-021-00215-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022] Open
Abstract
Background African swine fever (ASF), caused by the ASF virus (ASFV), was first reported in Vietnam in 2019 and spread rapidly thereafter. Better insights into ASFV characteristics and early detection by surveillance could help control its spread. However, the pathogenicity and methods for early detection of ASFV isolates from Vietnam have not been established. Therefore, we investigated the pathogenicity of ASFV and explored alternative sampling methods for early detection. Results Ten pigs were intramuscularly inoculated with an ASFV strain from Vietnam (titer, 103.5 HAD50/mL), and their temperature, clinical signs, and virus excretion patterns were recorded. In addition, herd and environmental samples were collected daily. The pigs died 5–8 days-post-inoculation (dpi), and the incubation period was 3.7 ± 0.5 dpi. ASFV genome was first detected in the blood (2.2 ± 0.8) and then in rectal (3.1 ± 0.7), nasal (3.2 ± 0.4), and oral (3.6 ± 0.7 dpi) swab samples. ASFV was detected in oral fluid samples collected using a chewed rope from 3 dpi. The liver showed the highest viral loads, and ear tissue also exhibited high viral loads among 11 tissues obtained from dead pigs. Overall, ASFV from Vietnam was classified as peracute to acute form. The rope-based oral fluid collection method could be useful for early ASFV detection and allows successful ASF surveillance in large pig farms. Furthermore, ear tissue samples might be a simple alternative specimen for diagnosing ASF infection in dead pigs. Conclusions Our data provide valuable insights into the characteristics of a typical ASFV strain isolated in Vietnam and suggest an alternative, non-invasive specimen collection strategy for early detection.
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Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute (ILRI), Hanoi, Vietnam
| | - Vuong Nghia Bui
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Duy Tung Dao
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Ngoc Anh Bui
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Thanh Duy Le
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Minh Anh Kieu
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Quang Huy Nguyen
- International Livestock Research Institute (ILRI), Hanoi, Vietnam.,Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Long Hoang Tran
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Jae-Hee Roh
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, 55365, Wanju, Republic of Korea
| | - Kyoung-Min So
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, 55365, Wanju, Republic of Korea
| | - Tai-Young Hur
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, 55365, Wanju, Republic of Korea
| | - Sang-Ik Oh
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, 55365, Wanju, Republic of Korea.
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Izzati UZ, Inanaga M, Hoa NT, Nueangphuet P, Myint O, Truong QL, Lan NT, Norimine J, Hirai T, Yamaguchi R. Pathological investigation and viral antigen distribution of emerging African swine fever in Vietnam. Transbound Emerg Dis 2020; 68:2039-2050. [PMID: 32979250 PMCID: PMC8359366 DOI: 10.1111/tbed.13851] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 07/29/2020] [Accepted: 09/18/2020] [Indexed: 11/30/2022]
Abstract
African swine fever (ASF) is emerging in Vietnam and poses a continuing severe threat to the swine industry. A histopathological study of clinical samples collected during the May to July 2019 outbreak of ASF was performed to determine the characteristic lesions. We analysed samples from eight ASFV‐infected farms. Histopathological results revealed the characteristic lesions of the acute to the subacute clinical form of ASF. Immunohistochemical results showed ASFV viral antigen distribution in mononuclear cells/macrophage in various organs, hepatocytes and renal tubular epithelium. Molecular analysis of partial capsid protein 72 gene revealed that ASFV strain from the eight separate outbreaks belonged to genotype II.
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Affiliation(s)
- Uda Zahli Izzati
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Minori Inanaga
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Nguyen Thi Hoa
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Phawut Nueangphuet
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Ohnmar Myint
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Quang Lam Truong
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Nguyen Thi Lan
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Junzo Norimine
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Takuya Hirai
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Ryoji Yamaguchi
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
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Papatsiros V, Stylianaki I, Papakonstantinou G, Tsekouras N, Bitchava D, Christodoulopoulos G, Papaioannou N. Histopathological Lesions Accompanied with First-Time Isolation of a PRRSV-2 Strain in Greece. Viral Immunol 2020; 33:565-570. [PMID: 33001795 DOI: 10.1089/vim.2020.0087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Genotype 2 strains of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV-2) have been reported sporadically in Europe. Even if, PRRSV-2 reported to be genetically homogenous in Europe due to the introduction of an MLV vaccine strain, independent introductions of PRRSV-2 field strains have been reported. The aim of the present study was to report the complete genome sequence and evaluate the histopathological lesions of a PRRSV-2 strain, isolated for the first time in Greece. During a routine blood sampling in a commercial pig farm, the results revealed positive samples in weaners of 40-60 days for the PRRSV-2, using real-time polymerase chain reaction. The clinical picture was characterized from respiratory symptoms in weaners, as well as coughing and poor performance at finishing stage and less than 3% mortality rate from weaning stage to finishing stage. The use of ORF5 for PRRSV phylogenetic analysis of the isolated PRRSV strain, named "x1544-1 strain", was successfully determined, belonging to the genotype PRRSV-2. Comparison of the obtained sequence revealed nucleotide sequence identity >98% with PRRSV-2 strain VR2332 and other related strains from Denmark and China. The histopathological evaluation revealed diffuse interstitial pneumonia, multifocal interstitial nephritis, while in the lymphoid organs, follicular and paracortical hyperplasia, coexisting with necrosis and depletion of germ cells were detected. The results of current study undersign the importance for veterinary practitioners to have up-to-date access to phylogenetic data linked to phenotypic information to follow-up the control and prevention strategies against PRRSV.
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Affiliation(s)
- Vasileios Papatsiros
- Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Ioanna Stylianaki
- Laboratory of Pathology, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Georgios Papakonstantinou
- Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Nikolaos Tsekouras
- Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | | | - Georgios Christodoulopoulos
- Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Nikolaos Papaioannou
- Laboratory of Pathology, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Lee HS, Pham TL, Nguyen TN, Lee M, Wieland B. Seasonal patterns and space-time clustering of porcine reproductive and respiratory syndrome (PRRS) cases from 2008 to 2016 in Vietnam. Transbound Emerg Dis 2019; 66:986-994. [PMID: 30636103 PMCID: PMC6850339 DOI: 10.1111/tbed.13122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 12/09/2018] [Accepted: 01/07/2019] [Indexed: 02/01/2023]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is an important disease in pig production and is endemic in Vietnam. No nationwide studies have been carried out to understand the spread of PRRS in Vietnam. The main objective of this study was to identify the seasonal patterns and space‐time clusters of PRRS from 2008 to 2016 using national surveillance data in Vietnam. A total of 614,219 cases were reported during the period. There was a seasonal pattern with single peak by region (except North Central Coast, showing double peaks in March and June). The seasonal plots from the Northern regions showed a higher peak between March and April, whereas the four regions from Southern part displayed a higher peak between June and August. Overall, outbreaks from the northern part of Vietnam tended to occur 3–4 months earlier than the southern part. When the spatial window was set at 50%, space‐time cluster analysis found that the first cluster occurred in the Red River Delta (RRD) (radius: 82.17 km; ratios: 5.5; period: Mar–May/2010) and the second (radius: 50.8 km; ratios: 10.61; period: Aug–Oct/2011) in the Mekong River Delta (MRD) region. Four other clusters were observed in the central and Southern parts. Our findings might provide better insight into the distribution of clusters and temporal patterns of PRRS in Vietnam. This study may provide policy makers with valuable information on the hotspot areas and timing of outbreaks. Also, it identifies when and where national control program could be implemented more efficiently by targeting resources for the prevention and control of PRRS.
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Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute (ILRI), Hanoi, Vietnam
| | - Thanh Long Pham
- Epidemiology Division, Department of Animal Health, Hanoi, Vietnam
| | - Tien Ngoc Nguyen
- Epidemiology Division, Department of Animal Health, Hanoi, Vietnam
| | - Mihye Lee
- Medical Microbiology Department, The Royal Bournemouth Hospital, Bournemouth, UK
| | - Barbara Wieland
- International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia
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5
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Senthilkumar D, Rajukumar K, Sen A, Kumar M, Shrivastava D, Kalaiyarasu S, Gautam S, Singh F, Kulkarni DD, Singh VP. Pathogenic characterization of porcine reproductive and respiratory syndrome virus of Indian origin in experimentally infected piglets. Transbound Emerg Dis 2018; 65:1522-1536. [PMID: 29790662 DOI: 10.1111/tbed.12893] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 03/28/2018] [Accepted: 04/09/2018] [Indexed: 12/15/2022]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is an economically important transboundary viral disease of pigs confronting the swine industry worldwide. This study was aimed to assess the pathogenic potential of PRRS virus belonging to genotype 2 that emerged in India in 2013. Nine 6-week-old piglets were inoculated intranasally with 2 × 105.75 TCID50 /ml of PRRSV (Ind-297221/2013). Three piglets were kept as uninfected controls. Blood and nasal swabs were collected daily up to 7 days post-infection (dpi) and on alternate days subsequently. Piglets were necropsied for tissue sample collection either on death or after euthanasia on 7, 14 or 21 dpi (one uninfected control and three PRRSV-infected piglets per interval). The virus caused high fever, typical blue ear, weight loss, respiratory distress, diarrhoea and leucopenia between 2 and 8 dpi. Two infected piglets died (on 3 and 17 dpi) during the course of study. The presence of virus in serum and nasal secretion was observed up to 19 and 17 dpi, respectively, with the maximum load between 4 and 7 dpi. Seroconversion started 6 dpi and the mean PRRSV antibody titre reached up to 640 by 21 dpi. Virus load was highest in tonsils at all the intervals, whereas in spleen and lymph nodes load was higher in later intervals. Major microscopic lesions in PRRSV-infected piglets included moderate to severe interstitial pneumonia, lymphoid depletion in tonsils and lymph nodes (cystic), thymic atrophy, reactive hyperplasia followed by lymphoid depletion in spleen. PRRSV antigen was consistently demonstrated by immunoperoxidase test in the lungs, spleen, tonsils and lymph nodes. Antigen distribution was more widespread on 7 and 14 dpi than on 21 dpi. The findings establish that the Indian PRRSV is highly pathogenic to piglets.
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Affiliation(s)
- D Senthilkumar
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - K Rajukumar
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - A Sen
- ICAR Research Complex for North East Hill Region, Barapani, Meghalaya, India
| | - M Kumar
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - D Shrivastava
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - S Kalaiyarasu
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - S Gautam
- ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - F Singh
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - D D Kulkarni
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - V P Singh
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
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Han J, Zhou L, Ge X, Guo X, Yang H. Pathogenesis and control of the Chinese highly pathogenic porcine reproductive and respiratory syndrome virus. Vet Microbiol 2017; 209:30-47. [PMID: 28292547 DOI: 10.1016/j.vetmic.2017.02.020] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 02/22/2017] [Accepted: 02/27/2017] [Indexed: 12/24/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) has remained a major threat to the worldwide swine industry ever since its first discovery in the early 1990s. Under the selective pressures in the field, this positive-stranded RNA virus undergoes rapid genetic evolution that eventually leads to emergence in 2006 of the devastating Chinese highly pathogenic PRRSV (HP-PRRSV). The atypical nature of HP-PRRSV has caused colossal economic losses to the swine producers in China and the surrounding countries. In this review, we summarize the recent advances in our understanding of the pathogenesis, evolution and ongoing field practices on the control of this troubling virus in China.
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Affiliation(s)
- Jun Han
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China
| | - Lei Zhou
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China
| | - Xinna Ge
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China
| | - Xin Guo
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China
| | - Hanchun Yang
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China.
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Iseki H, Kawashima K, Tung N, Inui K, Ikezawa M, Shibahara T, Yamakawa M. Efficacy of Type 2 porcine reproductive and respiratory syndrome virus (PRRSV) vaccine against the 2010 isolate of Vietnamese highly pathogenic PRRSV challenge in pigs. J Vet Med Sci 2017; 79:765-773. [PMID: 28239040 PMCID: PMC5402200 DOI: 10.1292/jvms.16-0536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The efficacy of a commercial attenuated live type 2 porcine reproductive and respiratory
syndrome (PRRS) vaccine was tested under experimental infection with a highly virulent
Vietnamese virus isolated from a diseased pig affected with highly pathogenic PRRS
(HP-PRRS) using specific pathogen-free (SPF) pigs. Twenty-five 4-week-old SPF pigs were
divided into three groups as follows: pigs vaccinated with a single dose of the vaccine
(Group 1, n=10), unvaccinated pigs (Group 2, n=10) and unvaccinated and non-infectious
control pigs (Group 3, n=5). Four weeks later, Groups 1 and 2 were challenged with a 1
ml inoculum containing 1 × 105.5 50% tissue culture
infectious dose (TCID50)/ml of a Vietnamese HP-PRRS virus
isolated in 2010 via the intranasal route. Animals were monitored during the subsequent
two-week period post-challenge and necropsied for virological and pathological assays.
Results showed a significant reduction in viral replication and shedding in vaccinated
pigs compared to unvaccinated pigs. The non-vaccinated pigs showed severe pyrogenic and
respiratory illness with marked systematic lesions including interstitial pneumonia and
thymic atrophy. In contrast, vaccinated pigs recovered quickly from fever with only mild
pathological manifestations. Therefore, although viral shedding was still noted,
immunization with the live PRRS vaccine did indeed reduce viral replication and disease
severity, suggesting its utility in minimizing outbreaks of HP-PRRS.
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Affiliation(s)
- Hiroshi Iseki
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 Japan
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