1
|
Kirkeby C, Boklund A, Larsen LE, Ward MP. Are all avian influenza outbreaks in poultry the same? The predicted impact of poultry species and virus subtype. Zoonoses Public Health 2024; 71:314-323. [PMID: 38362732 DOI: 10.1111/zph.13116] [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: 04/21/2023] [Revised: 11/15/2023] [Accepted: 01/30/2024] [Indexed: 02/17/2024]
Abstract
AIMS Outbreaks of avian influenza in poultry farms are currently increasing in frequency, with devastating consequences for animal welfare, farmers and supply chains. Some studies have documented the direct spread of the avian influenza virus between farms. Prevention of spread between farms relies on biosecurity surveillance and control measures. However, the evolution of an outbreak on a farm might vary depending on the virus strain and poultry species involved; this would have important implications for surveillance systems, epidemiological investigations and control measures. METHODS AND RESULTS In this study, we utilized existing parameter estimates from the literature to evaluate the predicted course of an epidemic in a standard poultry flock with 10,000 birds. We used a stochastic SEIR simulation model to simulate outbreaks in different species and with different virus subtypes. The simulations predicted large differences in the duration and severity of outbreaks, depending on the virus subtypes. For both turkeys and chickens, outbreaks with HPAI were of shorter duration than outbreaks with LPAI. In outbreaks involving the infection of chickens with different virus subtypes, the shortest epidemic involved H7N7 and HPAIV H5N1 (median duration of 9 and 17 days, respectively) and the longest involved H5N2 (median duration of 68 days). The most severe outbreaks (number of chickens infected) were predicted for H5N1, H7N1 and H7N3 virus subtypes, and the least severe for H5N2 and H7N7, in which outbreaks for the latter subtype were predicted to develop most slowly. CONCLUSIONS These simulation results suggest that surveillance of certain subtypes of avian influenza virus, in chicken flocks in particular, needs to be sensitive and timely if infection is to be detected with sufficient time to implement control measures. The variability in the predictions highlights that avian influenza outbreaks are different in severity, speed and duration, so surveillance and disease response need to be nuanced and fit the specific context of poultry species and virus subtypes.
Collapse
Affiliation(s)
- Carsten Kirkeby
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Anette Boklund
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Michael P Ward
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camden, New South Wales, Australia
| |
Collapse
|
2
|
Liu Y, Kjær LJ, Boklund AE, Hjulsager CK, Larsen LE, Kirkeby CT. Risk factors for avian influenza in Danish poultry and wild birds during the epidemic from June 2020 to May 2021. Front Vet Sci 2024; 11:1358995. [PMID: 38450025 PMCID: PMC10914952 DOI: 10.3389/fvets.2024.1358995] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 02/12/2024] [Indexed: 03/08/2024] Open
Abstract
Exploring the risk factors of avian influenza (AI) occurrence helps us to monitor and control the disease. Since late 2020, the number of avian influenza outbreaks in domestic and wild birds has increased in most European countries, including Denmark. This study was conducted to identify potential risk factors for wild birds and poultry during the epidemic in 2020/2021 in Denmark. Using Danish AI surveillance data of actively surveyed poultry and passively surveyed wild birds from June 2020 to May 2021, we calculated geographical attributes for bird locations and assessed the potential risk factors of AI detections using logistic regression analyses. 4% of actively surveyed poultry and 39% of passively surveyed wild birds were detected with AI circulating or ongoing at the time. Of these, 10 and 99% tested positive for the H5/H7 AI subtypes, respectively. Our analyses did not find any statistically significant risk factors for actively surveyed poultry within the dataset. For passively surveyed wild birds, bird species belonging to the Anseriformes order had a higher risk of being AI virus positive than five other taxonomic bird orders, and Galliformes were of higher risk than two other taxonomic bird orders. Besides, every 1 km increase in the distance to wetlands was associated with a 5.18% decrease in the risk of being AI positive (OR (odds ratio) 0.95, 95% CI 0.91, 0.99), when all other variables were kept constant. Overall, bird orders and distance to wetlands were associated with the occurrence of AI. The findings may provide targets for surveillance strategies using limited resources and assist in risk-based surveillance during epidemics.
Collapse
Affiliation(s)
- Yangfan Liu
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Lene Jung Kjær
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Anette Ella Boklund
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Carsten Thure Kirkeby
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
3
|
Hansen LG, Larsen LE, Rasmussen TB, Miar Y, Lassuniére R, Jørgensen CS, Ryt-Hansen P. Investigation of the SARS-CoV-2 post-vaccination antibody response in Canadian farmed mink. Vaccine 2023; 41:7387-7394. [PMID: 37932134 DOI: 10.1016/j.vaccine.2023.10.073] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/28/2023] [Accepted: 10/30/2023] [Indexed: 11/08/2023]
Abstract
Currently, SARS-CoV-2 have been detected in farmed mink in 13 different countries. Due to the high susceptibility and transmissibility among mink, great concerns of mink serving as a reservoir to generate novel variants with unknown virulence and antigenic properties arose. These concerns have consequently resulted in entire mink productions being culled and banned. This study investigates the post-vaccination antibody response in the Canadian farmed mink vaccinated with a commercial Index spike protein-based vaccine, approved for use in cats, and compares the antibody response to that observed post infection in Danish farmed mink. Blood samples were obtained from 50 mink at the Canadian Centre for Fur Animal Research (CCFAR), Dalhousie University (Truro, Canada). The sera were initially analyzed for antibodies by enzyme-linked immunosorbent assay (ELISA), and selected sera was subsequently tested in a virus neutralization tests. The levels of neutralizing antibodies were evaluated for an ancestral D614G strain and a recent circulating SARS-CoV-2 variant of concern (Omicron BA.4). The results revealed that the vaccine induced a strong antibody response in mink by reaching antibody titer levels of up to 1:12800 in the ELISA. Moreover, high levels of neutralizing antibodies were obtained, and despite the great level of genetic differences between the ancestral and Omicron BA.4 strains, the vaccinated mink showed high levels of cross-reacting neutralizing antibodies. Interestingly, the antibody levels towards SARS-CoV-2 in the Canadian vaccinated mink were significantly higher than observed in recently SARS-CoV-2 infected Danish mink and equal to anamnestic responses following re-infection. In conclusion, the vaccine used in the Canadian farmed mink was able to induce a strong and broad-reacting antibody response in mink, which could limit the spread of SARS-CoV-2 in farmed mink and thereby reduce the risk of mink serving as a SARS-CoV-2 reservoir for human infections.
Collapse
Affiliation(s)
- Line Gram Hansen
- Dpt. of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, DK-1870 Frederiksberg C, Denmark.
| | - Lars Erik Larsen
- Dpt. of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, DK-1870 Frederiksberg C, Denmark.
| | | | - Younes Miar
- Haley Institute of Animal Science and Aquaculture 100-A, Dalhousie University, Faculty of Agriculture, 58 Sipu Awti, Truro, NS, Canada.
| | - Ria Lassuniére
- Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark.
| | | | - Pia Ryt-Hansen
- Dpt. of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, DK-1870 Frederiksberg C, Denmark.
| |
Collapse
|
4
|
Jung Kjær L, Ward MP, Boklund AE, Larsen LE, Hjulsager CK, Kirkeby CT. Author Correction: Using surveillance data for early warning modelling of highly pathogenic avian influenza in Europe reveals a seasonal shift in transmission, 2016-2022. Sci Rep 2023; 13:16612. [PMID: 37789088 PMCID: PMC10547703 DOI: 10.1038/s41598-023-43740-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023] Open
Affiliation(s)
- Lene Jung Kjær
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Michael P Ward
- Faculty of Science, Sydney School of Veterinary Science, University of Sydney, Camden, NSW, Australia
| | - Anette Ella Boklund
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Carsten Thure Kirkeby
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
5
|
Jung Kjær L, Ward MP, Boklund AE, Larsen LE, Hjulsager CK, Kirkeby CT. Using surveillance data for early warning modelling of highly pathogenic avian influenza in Europe reveals a seasonal shift in transmission, 2016-2022. Sci Rep 2023; 13:15396. [PMID: 37717056 PMCID: PMC10505205 DOI: 10.1038/s41598-023-42660-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 04/21/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023] Open
Abstract
Avian influenza in wild birds and poultry flocks constitutes a problem for animal welfare, food security and public health. In recent years there have been increasing numbers of outbreaks in Europe, with many poultry flocks culled after being infected with highly pathogenic avian influenza (HPAI). Continuous monitoring is crucial to enable timely implementation of control to prevent HPAI spread from wild birds to poultry and between poultry flocks within a country. We here utilize readily available public surveillance data and time-series models to predict HPAI detections within European countries and show a seasonal shift that happened during 2021-2022. The output is models capable of monitoring the weekly risk of HPAI outbreaks, to support decision making.
Collapse
Affiliation(s)
- Lene Jung Kjær
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Michael P Ward
- Faculty of Science, Sydney School of Veterinary Science, University of Sydney, Camden, NSW, Australia
| | - Anette Ella Boklund
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Carsten Thure Kirkeby
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
6
|
Jensen KJ, Hansen MS, Skovgaard K, Svensson E, Larsen LE, Heegaard PMH, Benn CS, Jungersen G. Immunogenicity of Bacillus Calmette-Guérin in pigs: potential as a translational model of non-specific effects of BCG. Front Immunol 2023; 14:1219006. [PMID: 37520542 PMCID: PMC10374211 DOI: 10.3389/fimmu.2023.1219006] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 06/26/2023] [Indexed: 08/01/2023] Open
Abstract
Background Clinical and immunological studies in humans show that the live attenuated Bacillus Calmette-Guérin (BCG) vaccine has beneficial non-specific effects, increasing resistance against diseases other than tuberculosis. The underlying mechanisms are currently being explored. The pig exhibits considerable physiological similarity to humans in anatomy and physiology, suggesting that similar responses to BCG could be expected. Studies of the non-specific effects of BCG in pigs are scarce. We investigated the feasibility of using pigs as a large animal model to investigate the non-specific immunological effects of BCG. Methods In a series of experiments, we randomized newborn or young piglets from conventional farms to receiving BCG or placebo and investigated the persistence of live BCG bacteria in various tissues, the immunogenicity of BCG in ex vivo blood and in vitro stimulation assays, and the acute phase protein and clinical responses to heterologous infectious challenge with influenza A virus or Actinobacillus pleuropneumoniae. Results The BCG vaccine was generally well tolerated. In contrast to humans, no skin reaction in the form of abscesses, ulcers, or scars was observed. Live BCG was recovered from draining lymph nodes in 2/13 animals 20 weeks after vaccination. Specific in vitro responses of IFN-γ to antigen-specific re-stimulation with mycobacterial antigen were increased but not TNF-responses to TLR2 or TLR4 agonists. A few genes were differentially expressed in blood after vaccination, including the antiviral genes RIG-I and CSF1, although the effect disappeared after correction for multiple testing. Clinical symptoms after heterologous bacterial or viral respiratory infections did not differ, nor did virus copies in nasopharyngeal samples after the challenge. However, the acute phase protein response was significantly reduced in BCG-vaccinated animals after influenza challenge but not after A. pleuropneumoniae challenge. Discussion BCG was safe in pigs, inducing specific immunological responses, but our model did not corroborate the innate immunological responsiveness to BCG seen in humans. The dose of BCG or the bacterial and viral challenges may have been sub-optimal. Even so, the acute phase protein response to influenza infection was significantly reduced in BCG-vaccinated animals.
Collapse
Affiliation(s)
- Kristoffer Jarlov Jensen
- Bandim Health Project, University of Southern Denmark, Copenhagen, Denmark
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
- Copenhagen Phase IV Unit, Center for Clinical Research and Prevention and Department of Clinical Pharmacology, Copenhagen University Hospital – Bispebjerg and Frederiksberg, Frederiksberg, Denmark
| | - Mette Sif Hansen
- Institute for Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
- Center for Diagnostics, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Kerstin Skovgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Erik Svensson
- Department of Tuberculosis and Mycobacteria, Statens Serum Institut, Copenhagen, Denmark
| | - Lars Erik Larsen
- Institute for Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Peter M. H. Heegaard
- Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Christine Stabell Benn
- Bandim Health Project, University of Southern Denmark, Copenhagen, Denmark
- Danish Institute for Advanced Study, University of Southern Denmark, Odense, Denmark
| | - Gregers Jungersen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
- Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen, Denmark
| |
Collapse
|
7
|
Eriksen EØ, Kudirkiene E, Barington K, Goecke NB, Blirup-Plum SA, Nielsen JP, Olsen JE, Jensen HE, Pankoke K, Larsen LE, Liu G, Pedersen KS. An observational field study of porcine post-weaning diarrhea: clinical and microbiological findings, and fecal pH-measurements as a potential diagnostic tool. Porcine Health Manag 2023; 9:33. [PMID: 37434248 DOI: 10.1186/s40813-023-00325-x] [Citation(s) in RCA: 2] [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: 11/21/2022] [Accepted: 06/13/2023] [Indexed: 07/13/2023] Open
Abstract
BACKGROUND Recently, in-feed medicinal zinc has been phased out in pig production in the European Union. This makes updated knowledge about porcine post-weaning diarrhea (PWD) crucial. The objectives of the present study were to investigate (i) the clinical presentation of PWD in pigs housed in Danish herds that did not use medicinal zinc, specifically the prevalence of diarrhea and whether PWD was associated to clinical signs of dehydration or altered body temperature; (ii) which microorganism are associated to PWD; and iii) whether measurements of the fecal pH have a potential to be used diagnostically to differentiate between infectious etiologies in cases of PWD. RESULTS The prevalence of diarrhea varied considerably between the outbreaks in the nine studied herds (median = 0.58, range = 0.10; 0.94). In a cross-sectional design (n = 923), diarrhea was associated with reduced rectal temperature and alkaline feces. Diarrhea was also associated with observably reduced skin elasticity, possibly indicating dehydration. In both diarrheic case pigs (n = 87) and control pigs (n = 86), the presence of Brachyspira pilosicoli, Clostridium perfringens, Cryptosporidium spp., Cystoisopora suis, enterotoxigenic Escherichia coli, Lawsonia intracellularis, porcine circovirus types 2 and 3, rotavirus A, B, C, and H, Samonella enterica spp. enterica, and Trichuris suis was described. PWD was associated with high levels of enterotoxigenic E. coli shedding (odds ratio versus no E. coli detection = 4.79 [CI 1.14; 12.62]). Diarrhea was associated with high levels of rotavirus A shedding (odds ratio versus no/low rotavirus A = 3.80 [CI 1.33; 7.97]). The association between microbiological findings in diarrheic pigs and fecal pH was negligible. CONCLUSIONS Enterotoxigenic E. coli was confirmed to be a cause of PWD; however, cases of PWD where enterotoxigenic E. coli was not detected in high levels occurred commonly, and this adds to the increasing evidence suggesting that PWD is not necessarily a result of enteric colibacillosis. Rotaviral enteritis might be a differential diagnosis of PWD. pH-measurements cannot be used to differentiate between differential diagnoses for PWD.
Collapse
Affiliation(s)
- Esben Østergaard Eriksen
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark.
| | - Egle Kudirkiene
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Kristiane Barington
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Nicole Bakkegård Goecke
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Sophie Amalie Blirup-Plum
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Jens Peter Nielsen
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - John Elmerdahl Olsen
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Henrik Elvang Jensen
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Karen Pankoke
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Lars Erik Larsen
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Gang Liu
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
| | - Ken Steen Pedersen
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870, Frederiksberg C, Denmark
- Ø-Vet A/S, Køberupvej 33, 4700, Næstved, Denmark
| |
Collapse
|
8
|
Blirup-Plum SA, Jensen HE, Nielsen SS, Pankoke K, Hansen MS, Pedersen KS, Eriksen EØ, Nielsen JP, Olsen JE, Kudirkiene E, Larsen LE, Goecke NB, Barington K. Gastro-intestinal lesions are not relatable to diarrhoea or specific pathogens in post-weaning diarrhoea (PWD) in pigs. Acta Vet Scand 2023; 65:30. [PMID: 37400879 DOI: 10.1186/s13028-023-00693-y] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 06/23/2023] [Indexed: 07/05/2023] Open
Abstract
BACKGROUND Post-weaning diarrhoea (PWD) is a multifactorial condition and the most well documented infectious cause is enterotoxigenic Escherichia coli. The objective of the study was to investigate possible associations between pathological manifestations and pathogens in pigs with and without PWD. The study was conducted as a case-control study and included a total of 173 pigs from 9 different commercial intensive indoor production herds in eastern Denmark. RESULTS Based on clinical examination, a total of 89 piglets with PWD (cases) and 84 piglets without PWD (controls) were included. Most of the pigs (n = 105/173) presented gastric lesions, which were more frequently observed in the control group. The odds of gastric ulcers were lower among pigs with PWD compared to pigs without PWD with an odds ratio (OR) of 0.2 (0.0; 0.7). Abnormal content in the colon was associated with PWD, with an OR of 6.5 (3.2; 14.3). No apparent association was found between lesions and the various pathogens or a combination of these. The odds of neutrophilic granulocyte infiltration were lower in the jejunum among pigs with PWD (OR 0.3 [0.1; 0.6]) compared to pigs without PWD. The association between neutrophilic granulocyte infiltration in jejunum and PWD differed between the herds (P = 0.03). Furthermore, the associations between PWD and hyperleukocytosis (P = 0.04) or infiltration of eosinophilic granulocytes (P = 0.04) in ileum were also herd dependent. Histopathology revealed several lesions not relatable to PWD. CONCLUSION The association between lesions and specific pathogens or PWD is more complex than anticipated.
Collapse
Affiliation(s)
- Sophie Amalie Blirup-Plum
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark.
| | - Henrik Elvang Jensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Søren Saxmose Nielsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Karen Pankoke
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Mette Sif Hansen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Ken Steen Pedersen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
- Ø-Vet A/S, 4700, Næstved, Denmark
| | - Esben Østergaard Eriksen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Jens Peter Nielsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - John Elmerdahl Olsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Egle Kudirkiene
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Nicole Bakkegård Goecke
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Kristiane Barington
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| |
Collapse
|
9
|
Barington K, Eriksen EØ, Kudirkiene E, Pankoke K, Hartmann KT, Hansen MS, Jensen HE, Blirup-Plum SA, Jørgensen BM, Nielsen JP, Olsen JE, Goecke NB, Larsen LE, Pedersen KS. Lesions and pathogens found in pigs that died during the nursery period in five Danish farms. Porcine Health Manag 2023; 9:26. [PMID: 37264473 DOI: 10.1186/s40813-023-00319-9] [Citation(s) in RCA: 2] [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: 03/14/2023] [Accepted: 05/08/2023] [Indexed: 06/03/2023] Open
Abstract
BACKGROUND Diagnosing and treatment of diseases in pigs are important to maintain animal welfare, food safety and productivity. At the same time antimicrobial resistance is increasing, and therefore, antibiotic treatment should be reserved for individuals with a bacterial infection. The aim of the study was to investigate gross and histological lesions and related pathogens in pigs that died during the nursery period in five Danish farms. In addition, high throughput, real-time qPCR monitoring of specific porcine pathogens in fecal sock and oral fluid samples were carried out to investigate the between-farm and between-batch variation in the occurrence of pathogens. RESULTS Twenty-five batches of nursery pigs from five intensive, indoor herds were followed from weaning (approximately four weeks) to the end of nursery (seven to eight weeks post weaning). Gross and histological evaluation of 238 dead and 30 euthanized pigs showed the highest prevalence of lesions in the skin, respiratory system, gastrointestinal tract, and joints. Gross and histological diagnoses of lung and joint lesions agreed in 46.5% and 62.2% of selected pigs, respectively. Bacteriological detection of Escherichia coli, Streptococcus suis or Staphylococcus aureus infections in joints, lungs and livers was confirmed as genuine infection on immunohistochemical staining in 11 out of 70 tissue sections. The real-time qPCR analysis of pooled samples showed that most pathogens detected in feces and in oral fluid in general followed the same shedding patterns in consecutive batches within herds. CONCLUSIONS Gross assessment should be supplemented with a histopathological assessment especially when diagnosing lesions in the lungs and joints. Moreover, microbiological detection of pathogens should optimally be followed up by in situ identification to confirm causality. Furthermore, routine necropsies can reveal gastric lesions that may warrant a change in management. Real-time qPCR testing of fecal sock samples and oral fluid samples may be used to monitor the infections in the individual herd and testing one batch seems to have a good predictive value for subsequent batches within a herd. Overall, optimal diagnostic protocols will provide a more substantiated prescription of antibiotics.
Collapse
Affiliation(s)
- Kristiane Barington
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark.
| | - Esben Østergaard Eriksen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Egle Kudirkiene
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Karen Pankoke
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Katrine Top Hartmann
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Mette Sif Hansen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Henrik Elvang Jensen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Sophie Amalie Blirup-Plum
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Benjamin Meyer Jørgensen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Jens Peter Nielsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - John Elmerdahl Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Nicole Bakkegård Goecke
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
| | - Ken Steen Pedersen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, 1870, Frederiksberg C, Denmark
- Ø-Vet A/S, Køberupvej 33, 4700, Næstved, Denmark
| |
Collapse
|
10
|
Vereecke N, Kvisgaard LK, Baele G, Boone C, Kunze M, Larsen LE, Theuns S, Nauwynck H. Molecular Epidemiology of Porcine Parvovirus Type 1 (PPV1) and the Reactivity of Vaccine-Induced Antisera Against Historical and Current PPV1 Strains. Virus Evol 2022; 8:veac053. [PMID: 35815310 PMCID: PMC9252332 DOI: 10.1093/ve/veac053] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/13/2022] [Accepted: 06/14/2022] [Indexed: 11/14/2022] Open
Abstract
Porcine Parvovirus Type 1 (PPV1) contributes to important losses in the swine industry worldwide. During a PPV1 infection, embryos and fetuses are targeted, resulting in stillbirth, mummification, embryonic death, and infertility (SMEDI syndrome). Even though vaccination is common in gilts and sows, strains mainly belonging to the 27a-like group have been spreading in Europe since early 2000s, resulting in SMEDI problems and requiring in-depth studies into the molecular epidemiology and vaccination efficacy of commercial vaccines. Here, we show that PPV1 has evolved since 1855 [1737, 1933] at a rate of 4.71 × 10−5 nucleotide substitutions per site per year. Extensive sequencing allowed evaluating and reassessing the current PPV1 VP1-based classifications, providing evidence for the existence of four relevant phylogenetic groups. While most European strains belong to the PPV1a (G1) or PPV1b (G2 or 27a-like) group, most Asian and American G2 strains and some European strains were divided into virulent PPV1c (e.g. NADL-8) and attenuated PPV1d (e.g. NADL-2) groups. The increase in the swine population, vaccination degree, and health management (vaccination and biosafety) influenced the spread of PPV1. The reactivity of anti-PPV1 antibodies from sows vaccinated with Porcilis© Parvo, Eryseng© Parvo, or ReproCyc© ParvoFLEX against different PPV1 field strains was the highest upon vaccination with ReproCyc© ParvoFLEX, followed by Eryseng© Parvo, and Porcilis© Parvo. Our findings contribute to the evaluation of the immunogenicity of existing vaccines and support the development of new vaccine candidates. Finally, the potential roles of cluster-specific hallmark amino acids in elevated pathogenicity and viral entry are discussed.
Collapse
Affiliation(s)
- Nick Vereecke
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University , Merelbeke, Belgium
- PathoSense BV , Lier, Belgium
| | - Lise Kirstine Kvisgaard
- Veterinary Clinical Microbiology, Department of Veterinary and Animal Sciences, University of Copenhagen , Copenhagen, Denmark
| | - Guy Baele
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Leuven, Belgium
| | - Carine Boone
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University , Merelbeke, Belgium
| | - Marius Kunze
- Boehringer Ingelheim Vetmedica GmbH , Binger Str. 173, 55216 Ingelheim am Rhein, Germany
| | - Lars Erik Larsen
- Veterinary Clinical Microbiology, Department of Veterinary and Animal Sciences, University of Copenhagen , Copenhagen, Denmark
| | | | - Hans Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University , Merelbeke, Belgium
| |
Collapse
|
11
|
Pedersen K, Blirup-Plum SA, Kristensen CS, Kvisgaard LK, Skade L, Jensen HE, Larsen LE. Virological and Histopathological Findings in Boars Naturally Infected With Porcine Reproductive and Respiratory Syndrome Virus Type 1. Front Microbiol 2022; 13:874498. [PMID: 35633676 PMCID: PMC9130840 DOI: 10.3389/fmicb.2022.874498] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Major geographical transmission of porcine reproductive and respiratory syndrome virus (PRRSV) occurs via semen when a boar stud is infected. This happened in Denmark in 2019, providing an opportunity to compare previous experimental PRRSV boar studies with natural PRRSV-1 infection in boars. The aim of this study was to investigate the association between the presence of PRRSV RNA in serum, semen, testicles, and epididymis of boars naturally infected with PRRSV and to describe the histological lesions in the testes and epididymis combined with direct visualisation of PRRSV-infected cells by immunohistochemical staining (IHC). The exact timing of infection of each boar was not determined, but based on serology the boars were divided into two groups: acute and late infections. All boars included were sampled the same day. In this study, 35 boars and 10 healthy boars from another PRRSV-negative boar stud were included as histological controls. PRRSV RNA was found most often in serum (51%) and least frequently in semen (22%) and was more often detected in the reproductive tract in the acute phase of infection (p < 0.0001; RR: 2.58). Mononuclear cells and multinuclear giant cells were present in the adluminal compartment of the testis and epididymis in PRRSV-infected boars, but not in control boars (p < 0.05), which supports the hypothesis that macrophages are involved in the venereal spread of the virus.
Collapse
Affiliation(s)
- Kasper Pedersen
- SEGES Danish Pig Research Centre, Aarhus, Denmark.,Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | | | - Lise Kirstine Kvisgaard
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Lotte Skade
- SEGES Danish Pig Research Centre, Aarhus, Denmark
| | - Henrik Elvang Jensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
12
|
Ryt-Hansen P, Nielsen HG, Sørensen SS, Larsen I, Kristensen CS, Larsen LE. The role of gilts in transmission dynamics of swine influenza virus and impacts of vaccination strategies and quarantine management. Porcine Health Manag 2022; 8:19. [PMID: 35513878 PMCID: PMC9069814 DOI: 10.1186/s40813-022-00261-2] [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: 10/21/2021] [Accepted: 04/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Along with an expanding global swine production, the commercial housing and management of swine herds, provide an optimal environment for constant circulation of swine influenza virus (swIAV), thereby challenging farmers and veterinarian in determining optimal control measures. The aim of this study was to investigate the role of gilts in the swIAV transmission dynamics, and to evaluate the impact of different control measures such as quarantine and gilt vaccination. METHODS The study was conducted as a cross-sectional study in ten Danish sow herds, including five swIAV vaccinated and five unvaccinated herds. Blood- and nasal swab samples of gilts, first parity sows and their piglets were collected at different stages in the production system (quarantine in/out, mating, gestation and farrowing) and analyzed for the presence of swIAV and swIAV antibodies. Associations between the detection of swIAV, seroprevalence, antibody levels, sow and gilt vaccination strategy and quarantine biosecurity were thereafter investigated to identify possible risk factors for swIAV introductions and persistence within the herds. RESULTS Nine of the ten herds of the study had swIAV circulation and swIAV was detected in the quarantine, mating- and farrowing unit. The prevalence of seropositive gilts and first parity sows was significantly higher in the vaccinated herds, but swIAV was still present in nasal swabs from both gilts, first parity sows and piglets in these herds. Quarantine gilt vaccination and all-in/all-out management resulted in a significant reduction of swIAV positive gilts at the end of the quarantine period. CONCLUSION The results underline that herd vaccination and/or quarantine facilities are crucial to avoid swIAV introductions into sow herds.
Collapse
Affiliation(s)
- Pia Ryt-Hansen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, 1870, Frederiksberg C, Denmark.
| | - Henriette Guldberg Nielsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, 1870, Frederiksberg C, Denmark
| | - Simon Smed Sørensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, 1870, Frederiksberg C, Denmark
| | - Inge Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, 1870, Frederiksberg C, Denmark
| | | | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, 1870, Frederiksberg C, Denmark
| |
Collapse
|
13
|
Jensen KJ, Tolstrup LK, Knobel DL, Aaby P, Jungersen G, Larsen LE, Kristensen CS, Benn CS. Non-specific effects of maternal and offspring rabies vaccination on mortality and antibiotic use in a Danish pig herd: A randomized trial. Vaccine 2022; 40:1665-1673. [PMID: 33840563 DOI: 10.1016/j.vaccine.2021.03.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/17/2021] [Accepted: 03/24/2021] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Human non-live vaccines have been associated with detrimental non-specific effects (NSE), particularly in females. A large trial found 2-fold increased overall mortality in girls receiving a new malaria vaccine compared to the rabies vaccine used as a coontrol; a beneficial NSE of the rabies vaccine was proposed. Conversely, in dogs increased mortality was seen in females but not males following rabies vaccination of puppies born to immunized mothers. We investigated NSE of non-live rabies vaccine in piglets and the potential modifying effect of maternal priming with rabies vaccine. METHODS In a Danish herd of commercial rabies virus-free pigs, 575 pregnant sows (2-3 weeks before scheduled farrowing) and 5747 of their offspring (median 6-day-old) were allocated (1:1) to non-live rabies vaccine (Versiguard rabies vet) or no rabies vaccine. Outcomes were overall mortality and antibiotic treatment until departure from the nursery (approximately age 12 weeks/30 kgs). RESULTS Until weaning, overall offspring mortality was 2.2% (127 piglets died, rabies vaccine: n = 69; control: n = 58), the proportion ratio (PR) being 1.19 (95% confidence interval: 0.84-1.68). Until end of follow-up, mortality was 4.1% (233, rabies vaccine: n = 115; control = 118, PR: 0.97 (0.76-1.25)). Prior sow rabies vaccination did not affect piglet mortality. For mortality as well as risk of antibiotic treatment before weaning, there was indication of a beneficial effect of rabies vaccine in female piglets, but a negative effect in (castrated) male piglets from rabies-naïve sows. Prior sow vaccination significantly modified the vaccine effect estimate in female piglets toward a detrimental effect of rabies vaccine on treatment risk. These effects had waned by 12 weeks of age. CONCLUSION The study did not support the hypothesized beneficial NSE of rabies vaccine. Although under-powered for subgroup analyses, the study indicated effect modification by sex and maternal vaccination. Results could be different in a herd with higher mortality and infectious burden.
Collapse
Affiliation(s)
- Kristoffer Jarlov Jensen
- Bandim Health Project, Department of Clinical Research, University of Southern Denmark, Copenhagen, Denmark; Copenhagen Phase IV Unit, Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, Frederiksberg, Denmark; Department of Health Technology, Technical University of Denmark, Kgs Lyngby, Denmark.
| | | | - Darryn L Knobel
- Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis; Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - Peter Aaby
- Bandim Health Project, INDEPTH Network, Bissau, Guinea-Bissau
| | - Gregers Jungersen
- Center for Vaccine Research, Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Christine Stabell Benn
- Bandim Health Project, Department of Clinical Research, University of Southern Denmark, Copenhagen, Denmark; Danish Institute for Advanced Study, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
14
|
Eriksen EØ, Kudirkiene E, Christensen AE, Agerlin MV, Weber NR, Nødtvedt A, Nielsen JP, Hartmann KT, Skade L, Larsen LE, Pankoke K, Olsen JE, Jensen HE, Pedersen KS. Post-weaning diarrhea in pigs weaned without medicinal zinc: risk factors, pathogen dynamics, and association to growth rate. Porcine Health Manag 2021; 7:54. [PMID: 34627400 PMCID: PMC8501929 DOI: 10.1186/s40813-021-00232-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [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: 07/19/2021] [Accepted: 09/22/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Porcine post-weaning diarrhea (PWD) has reemerged as an important topic in pig production, as common control strategies based on prophylactic use of antimicrobials and zinc oxide have been deemed unsustainable. The objectives of this study were to estimate the cumulative incidence of porcine post-weaning diarrhea with different etiologies in production systems weaning without zinc oxide and prophylactic antimicrobials, to assess risk factors for post-weaning diarrhea, and to estimate the impact of post-weaning diarrhea on growth rate. A cohort study was conducted at two commercial indoor producers weaning without medicinal zinc oxide and prophylactic antimicrobials. RESULTS Piglets were included at birth (n = 300) and 272 survived until weaning. After insertion to the nursery units, the piglets were clinically examined every day for 14 days, and rectal swabs were collected and analyzed for enterotoxigenic Escherichia coli (ETEC) and rotavirus A. The cumulative incidences of PWD the first 14 days after insertion to the nursery units were 41.8% (CI 33.6, 50.4) and 51.1% (CI 42.3, 60.0) at the two producers, respectively. We found a low incidence of cases associated to ETEC, and detected a substantial proportion of cases associated to rotavirus. We observed a biphasic pattern in the assumed etiology with rotavirus occurring first, and then a shift towards cases associated to ETEC/non-ETEC hemolytic E. coli. Being offspring of older sows was a protective factor for the development of PWD (Hazard ratio = 0.88 [CI 0.78, 0.99] per unit increase in parity of the dam). Low birth weight reduced the post-weaning growth rate (- 5.2 g/day [CI - 7.5, - 2.9] per 100 g decrease in birthweight) and increased the hazard of developing PWD (Hazard ratio for birthweight below 1100 g: 2.30 [CI 1.41-3.74]). The combined effect of having diarrhea for 2 days or more and receiving antimicrobial treatment was associated with an increased average daily weight gain. CONCLUSIONS This study suggests novel insights regarding pathogen dynamics and risk factors for PWD in productions not using prophylactic antimicrobials and medicinal zinc. The findings may have important implications for both antimicrobial usage and prevention strategies.
Collapse
Affiliation(s)
| | - Egle Kudirkiene
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | - Ane Nødtvedt
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Jens Peter Nielsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Top Hartmann
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lotte Skade
- SEGES Danish Pig Research Centre, Copenhagen, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Karen Pankoke
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - John Elmerdahl Olsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Elvang Jensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ken Steen Pedersen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark.,Ø-Vet A/S, Næstved, Denmark
| |
Collapse
|
15
|
Glud HA, George S, Skovgaard K, Larsen LE. Zoonotic and reverse zoonotic transmission of viruses between humans and pigs. APMIS 2021; 129:675-693. [PMID: 34586648 PMCID: PMC9297979 DOI: 10.1111/apm.13178] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 04/12/2021] [Accepted: 08/28/2021] [Indexed: 12/30/2022]
Abstract
Humans and pigs share a close contact relationship, similar biological traits, and one of the highest estimated number of viruses compared to other mammalian species. The contribution and directionality of viral exchange between humans and pigs remain unclear for some of these viruses, but their transmission routes are important to characterize in order to prevent outbreaks of disease in both host species. This review collects and assesses the evidence to determine the likely transmission route of 27 viruses between humans and pigs.
Collapse
Affiliation(s)
- Helena Aagaard Glud
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Sophie George
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kerstin Skovgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
16
|
Pedersen K, Kristensen CS, Kvisgaard LK, Larsen LE. Impacts of Quarterly Sow Mass Vaccination with a Porcine Reproductive and Respiratory Syndrome Virus Type 1 (PRRSV-1) Modified Live Vaccine in Two Herds. Vaccines (Basel) 2021; 9:vaccines9101057. [PMID: 34696165 PMCID: PMC8537578 DOI: 10.3390/vaccines9101057] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/16/2021] [Accepted: 09/18/2021] [Indexed: 11/16/2022] Open
Abstract
In recent years, there has been a considerable increase in the use of Modified Live PRRSV Vaccines (MLV) for mass vaccination in Denmark. The potential risks and negative impact of this strategy have been sparsely studied. The aim of this study was to investigate the impact of quarterly sow mass vaccination in two Danish sow herds. The study was performed as an observational prospective cohort of 120 sows in each of two commercial breeding herds in a paired design. Blood samples were taken from sows and oral fluid samples from nursery pigs (four to ten weeks old) before and after vaccination. The presence of PRRSV-1 RNA was measured by real time quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and the level of PRRSV-1 specific antibodies was measured by two different serological assays. PRRS virus was not detected in the sow herds two days before and two weeks after vaccination, but the vaccine strain virus was detected in the nursery pigs. The prevalence of sows without antibodies towards PRRSV-1 went from 6-15% before vaccination to 1-4% after vaccination depending on the serological assay used, despite the fact that they had previously been repeatedly vaccinated. Four sows tested negative for antibodies in both assays after vaccination.
Collapse
Affiliation(s)
- Kasper Pedersen
- SEGES Danish Pig Research Centre, Agro Food Park 15V, 8200 Aarhus N, Denmark; (K.P.); (C.S.K.)
| | | | - Lise Kirstine Kvisgaard
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark;
| | - Lars Erik Larsen
- Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark;
- Correspondence:
| |
Collapse
|
17
|
Ryt-Hansen P, Krog JS, Breum SØ, Hjulsager CK, Pedersen AG, Trebbien R, Larsen LE. Co-circulation of multiple influenza A reassortants in swine harboring genes from seasonal human and swine influenza viruses. eLife 2021; 10:60940. [PMID: 34313225 PMCID: PMC8397370 DOI: 10.7554/elife.60940] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 07/10/2020] [Accepted: 07/21/2021] [Indexed: 12/11/2022] Open
Abstract
Since the influenza pandemic in 2009, there has been an increased focus on swine influenza A virus (swIAV) surveillance. This paper describes the results of the surveillance of swIAV in Danish swine from 2011 to 2018. In total, 3800 submissions were received with a steady increase in swIAV-positive submissions, reaching 56% in 2018. Full-genome sequences were obtained from 129 swIAV-positive samples. Altogether, 17 different circulating genotypes were identified including six novel reassortants harboring human seasonal IAV gene segments. The phylogenetic analysis revealed substantial genetic drift and also evidence of positive selection occurring mainly in antigenic sites of the hemagglutinin protein and confirmed the presence of a swine divergent cluster among the H1pdm09Nx (clade 1A.3.3.2) viruses. The results provide essential data for the control of swIAV in pigs and emphasize the importance of contemporary surveillance for discovering novel swIAV strains posing a potential threat to the human population.
Collapse
Affiliation(s)
- Pia Ryt-Hansen
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.,University of Copenhagen, Department of Health Sciences, Institute for Animal and Veterinary Sciences, Frederiksberg, Denmark
| | | | | | | | - Anders Gorm Pedersen
- Department of Health Technology, Section for Bioinformatics, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Lars Erik Larsen
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.,University of Copenhagen, Department of Health Sciences, Institute for Animal and Veterinary Sciences, Frederiksberg, Denmark
| |
Collapse
|
18
|
Liang Y, Krog JS, Ryt-Hansen P, Pedersen AG, Kvisgaard LK, Holm E, Nielsen PD, Hammer AS, Madsen JJ, Thorup K, Larsen LE, Hjulsager CK. Molecular Characterization of Highly Pathogenic Avian Influenza Viruses H5N6 Detected in Denmark in 2018-2019. Viruses 2021; 13:1052. [PMID: 34199456 PMCID: PMC8226499 DOI: 10.3390/v13061052] [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] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 02/07/2023] Open
Abstract
Beginning in late 2017, highly pathogenic avian influenza (HPAI) H5N6 viruses caused outbreaks in wild birds and poultry in several European countries. H5N6 viruses were detected in 43 wild birds found dead throughout Denmark. Most of the Danish virus-positive dead birds were found in the period from February to April 2018. However, unlike the rest of Europe, sporadic HPAI H5N6-positive dead wild birds were detected in Denmark in July, August, September, and December 2018, with the last positive bird being found in January 2019. HPAI viruses were not detected in active surveillance of apparently healthy wild birds. In this study, we use full genome sequencing and phylogenetic analysis to investigate the wild bird HPAI H5N6 viruses found in Denmark. The Danish viruses were found to be closely related to those of contemporary HPAI H5N6 viruses detected in Europe. Their sequences formed two clusters indicating that at least two or more introductions of H5N6 into Denmark occurred. Notably, all viruses detected in the latter half of 2018 and in 2019 grouped into the same cluster. The H5N6 viruses appeared to have been maintained undetected in the autumn 2018.
Collapse
Affiliation(s)
- Yuan Liang
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (Y.L.); (P.R.-H.); (L.K.K.); (A.S.H.); (L.E.L.)
| | - Jesper Schak Krog
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, 2300 Copenhagen S, Denmark; (J.S.K.); (E.H.)
| | - Pia Ryt-Hansen
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (Y.L.); (P.R.-H.); (L.K.K.); (A.S.H.); (L.E.L.)
| | - Anders Gorm Pedersen
- DTU Health Tech, Bioinformatics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark;
| | - Lise Kirstine Kvisgaard
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (Y.L.); (P.R.-H.); (L.K.K.); (A.S.H.); (L.E.L.)
| | - Elisabeth Holm
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, 2300 Copenhagen S, Denmark; (J.S.K.); (E.H.)
| | - Pernille Dahl Nielsen
- Animal Health Division, Danish Veterinary and Food Administration, 2600 Glostrup, Denmark;
| | - Anne Sofie Hammer
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (Y.L.); (P.R.-H.); (L.K.K.); (A.S.H.); (L.E.L.)
| | | | - Kasper Thorup
- GLOBE Institute, University of Copenhagen, 1350 Copenhagen, Denmark;
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (Y.L.); (P.R.-H.); (L.K.K.); (A.S.H.); (L.E.L.)
| | - Charlotte Kristiane Hjulsager
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, 2300 Copenhagen S, Denmark; (J.S.K.); (E.H.)
| |
Collapse
|
19
|
Klompmaker AF, Brydensholt M, Michelsen AM, Denwood MJ, Kirkeby CT, Larsen LE, Goecke NB, Otten ND, Nielsen LR. Estimating Clinically Relevant Cut-Off Values for a High-Throughput Quantitative Real-Time PCR Detecting Bacterial Respiratory Pathogens in Cattle. Front Vet Sci 2021; 8:674771. [PMID: 34113678 PMCID: PMC8185137 DOI: 10.3389/fvets.2021.674771] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 03/01/2021] [Accepted: 04/28/2021] [Indexed: 11/13/2022] Open
Abstract
Bovine respiratory disease (BRD) results from interactions between pathogens, environmental stressors, and host factors. Obtaining a diagnosis of the causal pathogens is challenging but the use of high-throughput real-time PCR (rtPCR) may help target preventive and therapeutic interventions. The aim of this study was to improve the interpretation of rtPCR results by analysing their associations with clinical observations. The objective was to develop and illustrate a field-data driven statistical method to guide the selection of relevant quantification cycle cut-off values for pathogens associated with BRD for the high-throughput rtPCR system "Fluidigm BioMark HD" based on nasal swabs from calves. We used data from 36 herds enrolled in a Danish field study where 340 calves within pre-determined age-groups were subject to clinical examination and nasal swabs up to four times. The samples were analysed with the rtPCR system. Each of the 1,025 observation units were classified as sick with BRD or healthy, based on clinical scores. The optimal rtPCR results to predict BRD were investigated for Pasteurella multocida, Mycoplasma bovis, Histophilus somni, Mannheimia haemolytica, and Trueperella pyogenes by interpreting scatterplots and results of mixed effects logistic regression models. The clinically relevant rtPCR cut-off suggested for P. multocida and M. bovis was ≤ 21.3. For H. somni it was ≤ 17.4, while no cut-off could be determined for M. haemolytica and T. pyogenes. The demonstrated approach can provide objective support in the choice of clinically relevant cut-offs. However, for robust performance of the regression model sufficient amounts of suitable data are required.
Collapse
Affiliation(s)
- Alicia F Klompmaker
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maria Brydensholt
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Marie Michelsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matthew J Denwood
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Carsten T Kirkeby
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicole B Goecke
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Centre for Diagnostics, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Nina D Otten
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Liza R Nielsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
20
|
Welner S, Ruggli N, Liniger M, Summerfield A, Larsen LE, Jungersen G. Reduced Virus Load in Lungs of Pigs Challenged with Porcine Reproductive and Respiratory Syndrome Virus after Vaccination with Virus Replicon Particles Encoding Conserved PRRSV Cytotoxic T-Cell Epitopes. Vaccines (Basel) 2021; 9:vaccines9030208. [PMID: 33801369 PMCID: PMC8000205 DOI: 10.3390/vaccines9030208] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/25/2021] [Accepted: 02/25/2021] [Indexed: 11/16/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) causes severe respiratory distress and reproductive failure in swine. Modified live virus (MLV) vaccines provide the highest degree of protection and are most often the preferred choice. While somewhat protective, the use of MLVs is accompanied by multiple safety issues, why safer alternatives are urgently needed. Here, we describe the generation of virus replicon particles (VRPs) based on a classical swine fever virus genome incapable of producing infectious progeny and designed to express conserved PRRSV-2 cytotoxic T-cell epitopes. Eighteen pigs matched with the epitopes by their swine leucocyte antigen-profiles were vaccinated (N = 11, test group) or sham-vaccinated (N = 7, control group) with the VRPs and subsequently challenged with PRRSV-2. The responses to vaccination and challenge were monitored using serological, immunological, and virological analyses. Challenge virus load in serum did not differ significantly between the groups, whereas the virus load in the caudal part of the lung was significantly lower in the test group compared to the control group. The number of peptide-induced interferon-γ secreting cells after challenge was higher and more frequent in the test group than in the control group. Together, our results provide indications of a shapeable PRRSV-specific cell-mediated immune response that may inspire future development of effective PRRSV vaccines.
Collapse
Affiliation(s)
- Simon Welner
- Section for Veterinary Clinical Microbiology, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlægevej 88, 1870 Frederiksberg C, Denmark;
- Correspondence:
| | - Nicolas Ruggli
- Institute of Virology and Immunology IVI, Sensemattstrasse 293, 3147 Mittelhäusern, Switzerland; (N.R.); (M.L.); (A.S.)
- Department of Infectious Diseases and Pathobiology (DIP), Vetsuisse Faculty, University of Bern, Länggassstrasse 120, 3012 Bern, Switzerland
| | - Matthias Liniger
- Institute of Virology and Immunology IVI, Sensemattstrasse 293, 3147 Mittelhäusern, Switzerland; (N.R.); (M.L.); (A.S.)
- Department of Infectious Diseases and Pathobiology (DIP), Vetsuisse Faculty, University of Bern, Länggassstrasse 120, 3012 Bern, Switzerland
| | - Artur Summerfield
- Institute of Virology and Immunology IVI, Sensemattstrasse 293, 3147 Mittelhäusern, Switzerland; (N.R.); (M.L.); (A.S.)
- Department of Infectious Diseases and Pathobiology (DIP), Vetsuisse Faculty, University of Bern, Länggassstrasse 120, 3012 Bern, Switzerland
| | - Lars Erik Larsen
- Section for Veterinary Clinical Microbiology, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlægevej 88, 1870 Frederiksberg C, Denmark;
| | - Gregers Jungersen
- Center for Vaccine Research, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark;
| |
Collapse
|
21
|
Kjaer LJ, Hjulsager CK, Larsen LE, Boklund AE, Halasa T, Ward MP, Kirkeby CT. Landscape effects and spatial patterns of avian influenza virus in Danish wild birds, 2006-2020. Transbound Emerg Dis 2021; 69:706-719. [PMID: 33600073 PMCID: PMC9291307 DOI: 10.1111/tbed.14040] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/22/2021] [Accepted: 02/16/2021] [Indexed: 11/28/2022]
Abstract
Avian influenza (AI) is a contagious disease of birds with zoonotic potential. AI virus (AIV) can infect most bird species, but clinical signs and mortality vary. Assessing the distribution and factors affecting AI presence can direct targeted surveillance to areas at risk of disease outbreaks, or help identify disease hotspots or areas with inadequate surveillance. Using virus surveillance data from passive and active AIV wild bird surveillance, 2006−2020, we investigated the association between the presence of AIV and a range of landscape factors and game bird release. Furthermore, we assessed potential bias in the passive AIV surveillance data submitted by the public, via factors related to public accessibility. Lastly, we tested the AIV data for possible hot‐ and cold spots within Denmark. The passive surveillance data was biased regarding accessibility to areas (distance to roads, cities and coast) compared to random locations within Denmark. For both the passive and active AIV surveillance data, we found significant (p < .01) associations with variables related to coast, wetlands and cities, but not game bird release. We used these variables to predict the risk of AIV presence throughout Denmark, and found high‐risk areas concentrated along the coast and fjords. For both passive and active surveillance data, low‐risk clusters were mainly seen in Jutland and northern Zealand, whereas high‐risk clusters were found in Jutland, Zealand, Funen and the southern Isles such as Lolland and Falster. Our results suggest that landscape affects AIV presence, as coastal areas and wetlands attract waterfowl and migrating birds and therefore might increase the potential for AIV transmission. Our findings have enabled us to create risk maps of AIV presence in wild birds and pinpoint high‐risk clusters within Denmark. This will aid targeted surveillance efforts within Denmark and potentially aid in planning the location of future poultry farms.
Collapse
Affiliation(s)
- Lene Jung Kjaer
- Faculty of Health and Medical Sciences, Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Lars Erik Larsen
- Faculty of Health and Medical Sciences, Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Anette Ella Boklund
- Faculty of Health and Medical Sciences, Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Tariq Halasa
- Faculty of Health and Medical Sciences, Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Michael P Ward
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Camden NSW, Australia
| | - Carsten Thure Kirkeby
- Faculty of Health and Medical Sciences, Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
22
|
Kristensen CS, Christiansen MG, Pedersen K, Larsen LE. Production losses five months after outbreak with a recombinant of two PRRSV vaccine strains in 13 Danish sow herds. Porcine Health Manag 2020; 6:26. [PMID: 33042567 PMCID: PMC7537099 DOI: 10.1186/s40813-020-00165-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 06/05/2020] [Accepted: 08/07/2020] [Indexed: 11/10/2022] Open
Abstract
Background In July 2019, a PRRSV-negative boar station was infected with a recombinant of two PRRSV vaccine strains, which subsequently spread to at least 36 herds that had received semen from the boar station. In the following months, all the infected herds reported reduced productivity. The aim of the present study was to evaluate the impact of the PRRS outbreak. Results Production data were collected from 13 of the herds. The average levels of farrowings/week, liveborns/litter, stillborns/litter, pre-weaning mortality and weaned pigs/litter were compared for the five-month period after infection and the preceding 7 months before infection with the new variant of PRRSV-1. Twelve herds experienced a decrease in farrowings/week (0.1-10.8% fewer farrowings/week), and all herds experienced fewer liveborns (0.8-4.8 fewer liveborns/litter) and more stillborns (0.6-2.6 more stillborns/litter). Pre-weaning mortality nearly doubled in half of the herds. Overall, the 13 herds were missing 2.4-6.5 pigs/litter at weaning during the 5 months after infection compared to the seven preceding months before infection. Conclusion In this study, the impact of this new PRRSV-1 variant on productivity exceeded that typically seen in Danish herds infected with PRRSV-1.
Collapse
Affiliation(s)
| | | | - K Pedersen
- SEGES Danish Pig Research Centre, Copenhagen, Denmark
| | - L E Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
23
|
Bhatta TR, Ryt-Hansen P, Nielsen JP, Larsen LE, Larsen I, Chamings A, Goecke NB, Alexandersen S. Infection Dynamics of Swine Influenza Virus in a Danish Pig Herd Reveals Recurrent Infections with Different Variants of the H1N2 Swine Influenza A Virus Subtype. Viruses 2020; 12:v12091013. [PMID: 32927910 PMCID: PMC7551734 DOI: 10.3390/v12091013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/06/2020] [Accepted: 09/08/2020] [Indexed: 12/15/2022] Open
Abstract
Influenza A virus (IAV) in swine, so-called swine influenza A virus (swIAV), causes respiratory illness in pigs around the globe. In Danish pig herds, a H1N2 subtype named H1N2dk is one of the main circulating swIAV. In this cohort study, the infection dynamic of swIAV was evaluated in a Danish pig herd by sampling and PCR testing of pigs from two weeks of age until slaughter at 22 weeks of age. In addition, next generation sequencing (NGS) was used to identify and characterize the complete genome of swIAV circulating in the herd, and to examine the antigenic variability in the antigenic sites of the virus hemagglutinin (HA) and neuraminidase (NA) proteins. Overall, 76.6% of the pigs became PCR positive for swIAV during the study, with the highest prevalence at four weeks of age. Detailed analysis of the virus sequences obtained showed that the majority of mutations occurred at antigenic sites in the HA and NA proteins of the virus. At least two different H1N2 variants were found to be circulating in the herd; one H1N2 variant was circulating at the sow and nursery sites, while another H1N2 variant was circulating at the finisher site. Furthermore, it was demonstrated that individual pigs had recurrent swIAV infections with the two different H1N2 variants, but re-infection with the same H1N2 variant was also observed. Better understandings of the epidemiology, genetic and antigenic diversity of swIAV may help to design better health interventions for the prevention and control of swIAV infections in the herds.
Collapse
Affiliation(s)
- Tarka Raj Bhatta
- Geelong Centre for Emerging Infectious Diseases, Geelong, VIC 3220, Australia;
- School of Medicine, Deakin University, Geelong, VIC 3220, Australia
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark; (P.R.-H.); (J.P.N.); (L.E.L.); (I.L.); (N.B.G.)
- Correspondence: (T.R.B.); (S.A.); Tel.: +61-0-452199095 (T.R.B.); +61-0-342159635 (S.A.)
| | - Pia Ryt-Hansen
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark; (P.R.-H.); (J.P.N.); (L.E.L.); (I.L.); (N.B.G.)
| | - Jens Peter Nielsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark; (P.R.-H.); (J.P.N.); (L.E.L.); (I.L.); (N.B.G.)
| | - Lars Erik Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark; (P.R.-H.); (J.P.N.); (L.E.L.); (I.L.); (N.B.G.)
| | - Inge Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark; (P.R.-H.); (J.P.N.); (L.E.L.); (I.L.); (N.B.G.)
| | - Anthony Chamings
- Geelong Centre for Emerging Infectious Diseases, Geelong, VIC 3220, Australia;
- School of Medicine, Deakin University, Geelong, VIC 3220, Australia
| | - Nicole B. Goecke
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark; (P.R.-H.); (J.P.N.); (L.E.L.); (I.L.); (N.B.G.)
- Division for Diagnostics & Scientific Advice, National Veterinary Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Soren Alexandersen
- Geelong Centre for Emerging Infectious Diseases, Geelong, VIC 3220, Australia;
- School of Medicine, Deakin University, Geelong, VIC 3220, Australia
- Barwon Health, University Hospital Geelong, Geelong, VIC 3220, Australia
- Correspondence: (T.R.B.); (S.A.); Tel.: +61-0-452199095 (T.R.B.); +61-0-342159635 (S.A.)
| |
Collapse
|
24
|
Kvisgaard LK, Kristensen CS, Ryt‐Hansen P, Pedersen K, Stadejek T, Trebbien R, Andresen LO, Larsen LE. A recombination between two Type 1 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV-1) vaccine strains has caused severe outbreaks in Danish pigs. Transbound Emerg Dis 2020; 67:1786-1796. [PMID: 32219985 PMCID: PMC7540543 DOI: 10.1111/tbed.13555] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [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: 12/11/2019] [Revised: 03/08/2020] [Accepted: 03/18/2020] [Indexed: 12/21/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is prevalent in Danish swine herds. In July 2019, PRRSV-1 was detected in a PRRSV-negative boar station and subsequently spread to more than 38 herds that had received semen from the boar station. Full genome sequencing revealed a sequence of 15.098 nucleotides. Phylogenetic analyses showed that the strain was a recombination between the Amervac strain (Unistrain PRRS vaccine; Hipra) and the 96V198 strain (Suvaxyn PRRS; Zoetis AH). The major parent was the 96V198 strain that spanned ORFs 1-2 and part of ORF 3 and the minor parent was the Amervac strain, which constituted the remaining part of the genome. The virus seems to be highly transmissible and has caused severe disease in infected herds despite a high level of genetic identity to the attenuated parent strains. The source of infection was presumable a neighbouring farm situated 5.8 km from the boar station.
Collapse
Affiliation(s)
| | | | - Pia Ryt‐Hansen
- National Veterinary InstituteTechnical University of DenmarkLyngbyDenmark
| | | | - Tomasz Stadejek
- Faculty of Veterinary MedicineWarsaw University of Life SciencesWarsawPoland
| | | | - Lars Ole Andresen
- National Veterinary InstituteTechnical University of DenmarkLyngbyDenmark
| | - Lars Erik Larsen
- National Veterinary InstituteTechnical University of DenmarkLyngbyDenmark
- Department of Health and Medical SciencesInstitute for Veterinary and Animal SciencesUniversity of CopenhagenCopenhagenDenmark
| |
Collapse
|
25
|
Ryt-Hansen P, Pedersen AG, Larsen I, Kristensen CS, Krog JS, Wacheck S, Larsen LE. Substantial Antigenic Drift in the Hemagglutinin Protein of Swine Influenza A Viruses. Viruses 2020; 12:v12020248. [PMID: 32102230 PMCID: PMC7077184 DOI: 10.3390/v12020248] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 02/18/2020] [Accepted: 02/20/2020] [Indexed: 12/16/2022] Open
Abstract
The degree of antigenic drift in swine influenza A viruses (swIAV) has historically been regarded as minimal compared to that of human influenza A virus strains. However, as surveillance activities on swIAV have increased, more isolates have been characterized, revealing a high level of genetic and antigenic differences even within the same swIAV lineage. The objective of this study was to investigate the level of genetic drift in one enzootically infected swine herd over one year. Nasal swabs were collected monthly from sows (n = 4) and piglets (n = 40) in the farrowing unit, and from weaners (n = 20) in the nursery. Virus from 1-4 animals were sequenced per month. Analyses of the sequences revealed that the hemagglutinin (HA) gene was the main target for genetic drift with a substitution rate of 7.6 × 10-3 substitutions/site/year and evidence of positive selection. The majority of the mutations occurred in the globular head of the HA protein and in antigenic sites. The phylogenetic tree of the HA sequences displayed a pectinate typology, where only a single lineage persists and forms the ancestor for subsequent lineages. This was most likely caused by repeated selection of a single immune-escape variant, which subsequently became the founder of the next wave of infections.
Collapse
Affiliation(s)
- Pia Ryt-Hansen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet Building 204, DK-2800 Kongens Lyngby, Denmark
- Dpt. of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, DK-1870 Frederiksberg C, Denmark; (I.L.); (L.E.L.)
- Correspondence:
| | - Anders Gorm Pedersen
- Department of Health Technology, Section for Bioinformatics, Technical University of Denmark, Kemitorvet Building 208, DK-2800 Kongens Lyngby, Denmark;
| | - Inge Larsen
- Dpt. of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, DK-1870 Frederiksberg C, Denmark; (I.L.); (L.E.L.)
| | | | - Jesper Schak Krog
- Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark;
| | - Silke Wacheck
- Ceva Santé Animale 10 Avenue de la Ballastière, 33500 Libourne, France;
| | - Lars Erik Larsen
- Dpt. of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, DK-1870 Frederiksberg C, Denmark; (I.L.); (L.E.L.)
| |
Collapse
|
26
|
Pansri P, Katholm J, Krogh KM, Aagaard AK, Schmidt LMB, Kudirkiene E, Larsen LE, Olsen JE. Evaluation of novel multiplex qPCR assays for diagnosis of pathogens associated with the bovine respiratory disease complex. Vet J 2020; 256:105425. [PMID: 32113583 PMCID: PMC7110767 DOI: 10.1016/j.tvjl.2020.105425] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 11/17/2022]
Abstract
Bovine respiratory disease complex is the most common disease requiring the use of antimicrobials in industrial calf production worldwide. Pathogenic bacteria (Mannheimia haemolytica (Mh), Pasteurella multocida (Pm), Histophilus somni (Hs), and Mycoplasma bovis) and a range of viruses (bovine respiratory syncytial virus, bovine coronavirus, bovine parainfluenza virus type 3, bovine viral diarrhea virus and bovine herpesvirus type 1) are associated with this complex. As most of these pathogens can be present in healthy and diseased calves, simple detection of their presence in diseased calves carries low predictive value. In other multi-agent diseases of livestock, quantification of pathogens has added substantially to the predictive value of microbiological diagnosis. The aim of this study was to evaluate the ability of two recently developed quantitative PCR (qPCR) kits (Pneumo4B and Pneumo4V) to detect and quantify these bacterial and viral pathogens, respectively. Test efficiencies of the qPCR assays, based on nucleic acid dilution series of target bacteria and viruses, were 93-106% and 91-104%, respectively, with assay detection limits of 10-50 copies of nucleic acids. All 44 strains of target bacteria were correctly identified, with no false positive reactions in 135strains of non-target bacterial species. Based on standard curves of log10 CFU versus cycle threshold (Ct) values, quantification was possible over a 5-log range of bacteria. In 92 tracheal aspirate samples, the kappa values for agreement between Pneumo4B and bacterial culture were 0.64-0.84 for Mh, Pm and Hs. In an additional 84 tracheal aspirates, agreement between Pneumo4B or Pneumo 4V and certified diagnostic qPCR assays was moderate (0.57) for M. bovis and high (0.71-0.90) for viral pathogens. Thus Pneumo4 kits specifically detected and quantified the relevant pathogens.
Collapse
Affiliation(s)
- P Pansri
- DNA Diagnostic, Risskov, Denmark
| | | | - K M Krogh
- LVK Veterinary Cattle Practice, Hobro, Denmark
| | - A K Aagaard
- Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen Denmark
| | - L M B Schmidt
- Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen Denmark
| | - E Kudirkiene
- Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen Denmark
| | - L E Larsen
- National Veterinary Laboratory, Technical University of Denmark, Lyngby, Denmark
| | - J E Olsen
- Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen Denmark.
| |
Collapse
|
27
|
Ryt-Hansen P, Pedersen AG, Larsen I, Krog JS, Kristensen CS, Larsen LE. Acute Influenza A virus outbreak in an enzootic infected sow herd: Impact on viral dynamics, genetic and antigenic variability and effect of maternally derived antibodies and vaccination. PLoS One 2019; 14:e0224854. [PMID: 31725751 PMCID: PMC6855628 DOI: 10.1371/journal.pone.0224854] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/23/2019] [Indexed: 02/07/2023] Open
Abstract
Influenza A virus (IAV) is a highly contagious pathogen in pigs. Swine IAV (swIAV) infection causes respiratory disease and is thereby a challenge for animal health, animal welfare and the production economy. In Europe, the most widespread strategy for controlling swIAV is implementation of sow vaccination programs, to secure delivery of protective maternally derived antibodies (MDAs) to the newborn piglets. In this study we report a unique case, where a persistently swIAV (A/sw/Denmark/P5U4/2016(H1N1)) infected herd experienced an acute outbreak with a new swIAV subtype (A/sw/Denmark/HB4280U1/2017(H1N2)) and subsequently decided to implement a mass sow vaccination program. Clinical registrations, nasal swabs and blood samples were collected from four different batches of pigs before and after vaccination. Virus isolation, sequencing of the virus strain and hemagglutinin inhibition (HI) tests were performed on samples collected before and during the outbreak and after implementation of mass sow vaccination. After implementation of the sow mass vaccination, the time of infection was delayed and the viral load significantly decreased. An increased number of pigs, however, tested positive at two consecutive sampling times indicating prolonged shedding. In addition, a significantly smaller proportion of the 10–12 weeks old pigs were seropositive by the end of the study, indicating an impaired induction of antibodies against swIAV in the presence of MDAs. Sequencing of the herd strains revealed major differences in the hemagglutinin gene of the strain isolated before- and during the acute outbreak despite that, the two strains belonged to the same HA lineage. The HI tests confirmed a limited degree of cross-reaction between the two strains. Furthermore, the sequencing results of the hemagglutinin gene obtained before and after implementation of mass sow vaccination revealed an increased substitution rate and an increase in positively selected sites in the globular head of the hemagglutinin after vaccination.
Collapse
Affiliation(s)
- Pia Ryt-Hansen
- National Veterinary Institute, Technical University of Denmark, Kongens Lyngby, Denmark
- * E-mail:
| | - Anders Gorm Pedersen
- Department of Health Technology, Section for Bioinformatics, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Inge Larsen
- University of Copenhagen, Dpt. of Veterinary and Animal Sciences, Frederiksberg C, Denmark
| | - Jesper Schak Krog
- National Veterinary Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Lars Erik Larsen
- National Veterinary Institute, Technical University of Denmark, Kongens Lyngby, Denmark
- University of Copenhagen, Dpt. of Veterinary and Animal Sciences, Frederiksberg C, Denmark
| |
Collapse
|
28
|
Ryt-Hansen P, Larsen I, Kristensen CS, Krog JS, Larsen LE. Limited impact of influenza A virus vaccination of piglets in an enzootic infected sow herd. Res Vet Sci 2019; 127:47-56. [PMID: 31677416 DOI: 10.1016/j.rvsc.2019.10.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [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: 08/09/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 01/15/2023]
Abstract
Recent studies have questioned the effect of maternal derived antibodies (MDAs) to protect piglets against infection with influenza A virus (IAV). The lack of protection against IAV infections provided by MDAs has encouraged alternative vaccination strategies targeting young piglets in an attempt to stimulate an early antibody response. There is a lack of studies documenting the efficacy of piglet vaccination. In the present study, we monitored a group of vaccinated and non-vaccinated piglets in a Danish sow herd that initiated piglet vaccination with ¼ dose of an inactivated swine influenza vaccine at the time of castration (day 3-4). A total of 160 piglets from 11 sows were included and either vaccinated with 0.5 mL inactivated swine influenza vaccine or sham-vaccinated. From week 0 until week 6, all included piglets were clinically examined and nasal swapped once per week and weighed at weeks 0, 3 and 6. Blood samples were collected from sows at week 0 and from piglets at week 3. Vaccination of piglets had limited effect on clinical signs, body weight, antibody development and viral shedding, within the first 6 weeks of life. At least 50% of all pigs of each treatment group tested positive for IAV at week 2, and very early onset of IAV shedding was observed. In total, 18 pigs were IAV positive in nasal swabs for more than one consecutive sampling time indicating prolonged shedding and 14 pigs were IAV positive with negative samplings in between indicating re-infection with the same IAV strain.
Collapse
Affiliation(s)
- Pia Ryt-Hansen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet Building 204, DK-2800 Kongens Lyngby, Denmark.
| | - Inge Larsen
- Dpt. of Veterinary and Animal Sciences Grønnegårdsvej 2, University of Copenhagen, DK-1870 Frederiksberg C, Denmark.
| | | | - Jesper Schak Krog
- National Veterinary Institute, Technical University of Denmark, Kemitorvet Building 204, DK-2800 Kongens Lyngby, Denmark.
| | - Lars Erik Larsen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet Building 204, DK-2800 Kongens Lyngby, Denmark; Dpt. of Veterinary and Animal Sciences Grønnegårdsvej 2, University of Copenhagen, DK-1870 Frederiksberg C, Denmark.
| |
Collapse
|
29
|
Ryt-Hansen P, Larsen I, Kristensen CS, Krog JS, Wacheck S, Larsen LE. Longitudinal field studies reveal early infection and persistence of influenza A virus in piglets despite the presence of maternally derived antibodies. Vet Res 2019; 50:36. [PMID: 31113477 PMCID: PMC6530179 DOI: 10.1186/s13567-019-0655-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/24/2019] [Indexed: 12/14/2022] Open
Abstract
A longitudinal study was performed in three Danish farrow to grower (30 kilos) herds over a 4-month period to investigate the dynamics and clinical impacts of influenza A virus (IAV) infections. In each herd, four batches consisting of four sows each with five ear-tagged piglets were included. Nasal swabs and/or blood were sampled from the sows and/or the piglets prior to farrowing and at weeks 1, 3, and 5 and at the end of the nursery period. Clinical examinations were performed at each sampling time. The sows and piglets were tested for IAV and IAV antibodies in nasal swabs and blood samples, respectively. The results revealed three enzootically infected herds, where the majority of the pigs were infected during the first 5 weeks after birth. Infected piglets of only 3 days of age were detected in the farrowing unit, where the sows were also shedding virus. In all herds, low to moderate numbers of infected pigs (ranging from 3.6 to 20.7%) were found to be virus positive in nasal swabs at two consecutive sampling times. Furthermore, clinical signs of respiratory disease were associated with IAV detection. The findings of this study documented that IAV can persist in herds and that piglets as young as 3 days can be infected despite the presence of maternally derived antibodies.
Collapse
Affiliation(s)
- Pia Ryt-Hansen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet Building 204, 2800, Kongens Lyngby, Denmark.
| | - Inge Larsen
- Dpt. of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, 1870, Frederiksberg C, Denmark
| | | | - Jesper Schak Krog
- National Veterinary Institute, Technical University of Denmark, Kemitorvet Building 204, 2800, Kongens Lyngby, Denmark
| | - Silke Wacheck
- IDT Biologika GmbH, Am Pharmapark, 06861, Dessau-Rosslau, Germany
| | - Lars Erik Larsen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet Building 204, 2800, Kongens Lyngby, Denmark
| |
Collapse
|
30
|
Kongsted H, Pedersen K, Hjulsager CK, Larsen LE, Pedersen KS, Jorsal SE, Bækbo P. Diarrhoea in neonatal piglets: a case control study on microbiological findings. Porcine Health Manag 2018; 4:17. [PMID: 30186621 PMCID: PMC6120089 DOI: 10.1186/s40813-018-0094-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 02/20/2018] [Accepted: 06/25/2018] [Indexed: 01/03/2023] Open
Abstract
Background Many factors can influence the occurrence of neonatal diarrhoea in piglets. Currently, well-known pathogens such as enterotoxigenic Escherichia coli and Clostridium perfringens type C appear to play a minor role in development of disease. Other infectious pathogens may be involved. In this study, we aimed to investigate the presence of selected infectious pathogens in neonatal piglets with clinical and pathological signs of enteric disease. The association between rotavirus A, Enterococcus hirae, Clostridium difficile and Clostridium perfringens type A/C and diarrhoea was investigated in a case control study on piglet level. The possible role of E. coli virulence factors was investigated in a multistep-procedure using herd-pools of E.coli isolates to screen for their presence. Results Rotavirus A was detected more often in cases (25%) than in controls (6%) (P < 0.001). The detection rate of Enterococcus hirae, Clostridium difficile and C. perfringens type A positive for beta2 genes was the same in the two groups of piglets. C. perfringens type C was not detected in the study. Investigations on E. coli virulence factors showed a high prevalence of EAST1 toxin genes (55% of tested case piglets were positive) and AIDA-1 adhesin genes (63% of toxin positive case piglets were positive) in case piglets. Conclusions Detection of rotavirus A was statistically significantly associated with neonatal piglet diarrhoea. An aetiologic role of E. coli carrying virulence factors EAST1 and AIDA-1 needs further investigation as the study points out these two factors as possible causative factors in neonatal diarrhoea. Detection of E.hirae, C.difficile and C. perfringens type A carrying beta 2 genes was not associated with neonatal piglet diarrhoea. However, the study suggested that massive overgrowth by E. hirae could be part of the pathogenesis in some cases of neonatal diarrhoea. Electronic supplementary material The online version of this article (10.1186/s40813-018-0094-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Hanne Kongsted
- 1Department of Animal Science, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark.,SEGES Danish Pig Research Centre, Axeltorv 3, DK-1609 Copenhagen V, Denmark
| | - Karl Pedersen
- 3National Veterinary Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | | | - Lars Erik Larsen
- 3National Veterinary Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Ken Steen Pedersen
- SEGES Danish Pig Research Centre, Axeltorv 3, DK-1609 Copenhagen V, Denmark
| | - Sven Erik Jorsal
- 3National Veterinary Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Poul Bækbo
- SEGES Danish Pig Research Centre, Axeltorv 3, DK-1609 Copenhagen V, Denmark
| |
Collapse
|
31
|
Franzo G, Legnardi M, Hjulsager CK, Klaumann F, Larsen LE, Segales J, Drigo M. Full-genome sequencing of porcine circovirus 3 field strains from Denmark, Italy and Spain demonstrates a high within-Europe genetic heterogeneity. Transbound Emerg Dis 2018; 65:602-606. [PMID: 29453822 DOI: 10.1111/tbed.12836] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [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: 09/16/2017] [Indexed: 01/18/2023]
Abstract
Porcine circovirus 3 (PCV3) is a new species of the Circovirus genus, which has recently been associated with different clinical syndromes. Its presence has been reported in different countries of North and South America, Asia and recently also Europe (Poland). However, different from the other continents, no European PCV3 sequence is currently available in public databases. There is a strong need of epidemiological data and full-genome sequences from Europe because of its relevance in the understanding of PCV3 molecular epidemiology and control. To fill this lack of information, samples collected in Denmark, Italy and Spain in 2016 and 2017 were screened for PCV3. Of the Danish samples, 36 of 38 the lymph nodes, six of 20 serum samples and two of 20 lung samples tested positive. Similarly, 10 of 29 lungs, 20 of 29 organ pools, six of 33 sera and one of eight nasal swabs tested PCV3 positive in Italy. Fourteen of 94 serum pools from seven of 14 Spanish farms were also positive. Despite the convenience nature of the sampling prevents any precise prevalence estimation, the preliminary screening of the data from three European countries confirmed a rather wide PCV3 distribution in Europe. Furthermore, the analysis of the six obtained complete European PCV3 genomes and their comparison with the public available sequences seems to support a remarkable worldwide PCV3 circulation. These results underline once more the urgency of more extensive epidemiological studies to refine the current knowledge on PCV3 evolution, transmission, spreading patterns and impact on pig health.
Collapse
Affiliation(s)
- G Franzo
- Department of Animal Medicine, Production and Health (MAPS), University of Padua, Legnaro, Italy
| | - M Legnardi
- Department of Animal Medicine, Production and Health (MAPS), University of Padua, Legnaro, Italy
| | - C K Hjulsager
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark
| | - F Klaumann
- Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), IRTA, Bellaterra, Spain
| | - L E Larsen
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark
| | - J Segales
- Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), UAB, Bellaterra, Spain.,Facultat de Veterinària, Departament de Sanitat i Anatomia Animals, UAB, Barcelona, Spain
| | - M Drigo
- Department of Animal Medicine, Production and Health (MAPS), University of Padua, Legnaro, Italy
| |
Collapse
|
32
|
Kristensen CS, Kvisgaard LK, Pawlowski M, Holmgaard Carlsen S, Hjulsager CK, Heegaard PMH, Bøtner A, Stadejek T, Haugegaard S, Larsen LE. Efficacy and safety of simultaneous vaccination with two modified live virus vaccines against porcine reproductive and respiratory syndrome virus types 1 and 2 in pigs. Vaccine 2017; 36:227-236. [PMID: 29191738 DOI: 10.1016/j.vaccine.2017.11.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [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: 07/24/2017] [Revised: 11/17/2017] [Accepted: 11/18/2017] [Indexed: 11/25/2022]
Abstract
The objective of the study was to compare responses of pigs vaccinated with a PRRS MLV vaccine against PRRSV-1 or PRRSV-2 with the responses of pigs vaccinated simultaneously with both vaccines. Furthermore, the efficacy of the two PRRSV MLV vaccination strategies was assessed following challenge. The experimental design included four groups of 4-weeks old SPF-pigs. On day 0 (DPV0), groups 1-3 (N=18 per group) were vaccinated with modified live virus vaccines (MLV) containing PRRSV-1 virus (VAC-T1), PRRSV-2 virus (VAC-T2) or both (VAC-T1T2). One group was left unvaccinated (N=12). On DPV 62, the pigs from groups 1-4 were mingled in new groups and challenged (DPC 0) with PRRSV-1, subtype 1, PRRSV-1, subtype 2 or PRRSV-2. On DPC 13/14 all pigs were necropsied. Samples were collected after vaccination and challenge. PRRSV was detected in all vaccinated pigs and the majority of the pigs were positive until DPV 28, but few of the pigs were still viremic 62 days after vaccination. Virus was detected in nasal swabs until DPV 7-14. No overt clinical signs were observed after challenge. PRRSV-2 vaccination resulted in a clear reduction in viral load in serum after PRRSV-2 challenge, whereas there was limited effect on the viral load in serum following challenge with the PRRSV-1 strains. Vaccination against PRRSV-1 had less impact on viremia following challenge. The protective effects of simultaneous vaccination with PRRSV Type 1 and 2 MLV vaccines and single PRRS MLV vaccination were comparable. None of the vaccines decreased the viral load in the lungs at necropsy. In conclusion, simultaneous vaccination with MLV vaccines containing PRRSV-1 and PRRSV-2 elicited responses comparable to single vaccination and the commercial PRRSV vaccines protected only partially against challenge with heterologous strains. Thus, simultaneous administration of the two vaccines is an option in herds with both PRRSV types.
Collapse
Affiliation(s)
| | - L K Kvisgaard
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.
| | - M Pawlowski
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark
| | - S Holmgaard Carlsen
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark
| | - C K Hjulsager
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.
| | - P M H Heegaard
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.
| | - A Bøtner
- Technical University of Denmark, National Veterinary Institute, Lindholm, Denmark.
| | - T Stadejek
- Warsaw University of Life Sciences, Faculty of Veterinary Medicine, Warsaw, Poland.
| | - S Haugegaard
- Danish Pig Research Centre, Danish Agriculture & Food Council, Kjellerup, Denmark.
| | - L E Larsen
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.
| |
Collapse
|
33
|
Goecke NB, Hjulsager CK, Kongsted H, Boye M, Rasmussen S, Granberg F, Fischer TK, Midgley SE, Rasmussen LD, Angen Ø, Nielsen JP, Jorsal SE, Larsen LE. No evidence of enteric viral involvement in the new neonatal porcine diarrhoea syndrome in Danish pigs. BMC Vet Res 2017; 13:315. [PMID: 29115952 PMCID: PMC5678564 DOI: 10.1186/s12917-017-1239-5] [Citation(s) in RCA: 14] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 10/30/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The aim of this study was to investigate whether the syndrome New Neonatal Porcine Diarrhoea Syndrome (NNPDS) is associated with a viral aetiology. Four well-managed herds experiencing neonatal diarrhoea and suspected to be affected by NNPDS were included in a case-control set up. A total of 989 piglets were clinically examined on a daily basis. Samples from diarrhoeic and non-diarrhoeic piglets at the age of three to seven days were selected for extensive virological examination using specific real time polymerase chain reactions (qPCRs) and general virus detection methods. RESULTS A total of 91.7% of the animals tested positive by reverse transcription qPCR (RT-qPCR) for porcine kobuvirus 1 (PKV-1) while 9% and 3% were found to be positive for rotavirus A and porcine teschovirus (PTV), respectively. The overall prevalence of porcine astrovirus (PAstV) was 75% with 69.8% of the PAstV positive pigs infected with PAstV type 3. No animals tested positive for rotavirus C, coronavirus (TGEV, PEDV and PRCV), sapovirus, enterovirus, parechovirus, saffoldvirus, cosavirus, klassevirus or porcine circovirus type 2 (PCV2). Microarray analyses performed on a total of 18 animals were all negative, as were eight animals examined by Transmission Electron Microscopy (TEM). Using Next Generation de novo sequencing (de novo NGS) on pools of samples from case animals within all herds, PKV-1 was detected in four herds and rotavirus A, rotavirus C and PTV were detected in one herd each. CONCLUSIONS Our detailed analyses of piglets from NNPDS-affected herds demonstrated that viruses did not pose a significant contribution to NNPDS. However, further investigations are needed to investigate if a systemic virus infection plays a role in the pathogenesis of NNPDS.
Collapse
Affiliation(s)
- N B Goecke
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, Lyngby, DK-2800, Denmark.
| | - C K Hjulsager
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, Lyngby, DK-2800, Denmark
| | - H Kongsted
- Pig Research Centre, Danish Agriculture and Food Council, Vinkelvej 13, DK-8620, Kjellerup, Denmark
| | - M Boye
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, Lyngby, DK-2800, Denmark.,Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Gronnegaardsvej 15, DK-1870, Frederiksberg, Denmark
| | - S Rasmussen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, Lyngby, DK-2800, Denmark
| | - F Granberg
- Department of Biomedical Sciences and Veterinary Public Health (BVF), Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - T K Fischer
- Statens Serum Institut (SSI), Artillerivej 5, Copenhagen S, DK-2300, Denmark
| | - S E Midgley
- Statens Serum Institut (SSI), Artillerivej 5, Copenhagen S, DK-2300, Denmark
| | - L D Rasmussen
- Statens Serum Institut (SSI), Artillerivej 5, Copenhagen S, DK-2300, Denmark.,National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave, DK-4771, Denmark
| | - Ø Angen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, Lyngby, DK-2800, Denmark.,Statens Serum Institut (SSI), Artillerivej 5, Copenhagen S, DK-2300, Denmark
| | - J P Nielsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Gronnegaardsvej 15, DK-1870, Frederiksberg, Denmark
| | - S E Jorsal
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, Lyngby, DK-2800, Denmark
| | - L E Larsen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, Lyngby, DK-2800, Denmark
| |
Collapse
|
34
|
Abstract
In late February 2014, unusually high numbers of wild thick-billed murres (Uria lomvia) were found dead on the coast of South Greenland. To investigate the cause of death, 45 birds were submitted for laboratory examination in Denmark. Avian influenza viruses (AIVs) with subtypes H11N2 and low pathogenic H5N1 were detected in some of the birds. Characterization of the viruses by full genome sequencing revealed that all the gene segments belonged to the North American lineage of AIVs. The seemingly sparse and mixed subtype occurrence of low pathogenic AIVs in these birds, in addition to the emaciated appearance of the birds, suggests that the murre die-off was due to malnutrition as a result of sparse food availability or inclement weather. Here we present the first characterization of AIVs isolated in Greenland, and our results support the idea that wild birds in Greenland may be involved in the movement of AIV between North America and Europe.
Collapse
Affiliation(s)
- Christina Marie Hartby
- National Veterinary Institute, Technical University of Denmark, 1870 Frederiksberg, Denmark
| | - Jesper Schak Krog
- National Veterinary Institute, Technical University of Denmark, 1870 Frederiksberg, Denmark
| | - Flemming Merkel
- Greenland Institute of Natural Resources, 3900 Nuuk, Greenland.,Arctic Environment, Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark
| | - Elisabeth Holm
- National Veterinary Institute, Technical University of Denmark, 1870 Frederiksberg, Denmark
| | - Lars Erik Larsen
- National Veterinary Institute, Technical University of Denmark, 1870 Frederiksberg, Denmark
| | | |
Collapse
|
35
|
Baratelli M, Pedersen LE, Trebbien R, Larsen LE, Jungersen G, Blanco E, Nielsen J, Montoya M. Identification of cross-reacting T-cell epitopes in structural and non-structural proteins of swine and pandemic H1N1 influenza A virus strains in pigs. J Gen Virol 2017; 98:895-899. [PMID: 28555545 DOI: 10.1099/jgv.0.000748] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heterologous protection against swine influenza viruses (SwIVs) of different lineages is an important concern for the pig industry. Cross-protection between 'avian-like' H1N1 and 2009 pandemic H1N1 lineages has been observed previously, indicating the involvement of cross-reacting T-cells. Here, reverse vaccinology was applied to identify cross-reacting MHC class I T-cell epitopes from two different SwIV H1 lineages in pigs. In silico prediction followed by in vitro and in vivo testing was used to identify SLA-1*0702 T-cell epitopes in heterologous SwIV-infected pigs. Following viral infection, tetramer specific T-cell populations were identified. The majority of the identified T-cell epitopes were conserved between the examined lineages, suggesting that targeting cross-reactive T-cell epitopes could be used to improve vaccines against SwIV in SLA-1*0702-positive pigs.
Collapse
Affiliation(s)
- Massimiliano Baratelli
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Lasse Eggers Pedersen
- Technical University of Denmark, National Veterinary Institute (DTU VET), 1870 Frederiksberg C and 4771 Kalvehave, Denmark
| | - Ramona Trebbien
- Technical University of Denmark, National Veterinary Institute (DTU VET), 1870 Frederiksberg C and 4771 Kalvehave, Denmark.,Statens Serum Institut, 5 Artillerivej, Copenhagen 2300, Denmark
| | - Lars Erik Larsen
- Technical University of Denmark, National Veterinary Institute (DTU VET), 1870 Frederiksberg C and 4771 Kalvehave, Denmark
| | - Gregers Jungersen
- Technical University of Denmark, National Veterinary Institute (DTU VET), 1870 Frederiksberg C and 4771 Kalvehave, Denmark
| | - Esther Blanco
- Centro de Investigación en Sanidad Animal, INIA, Valdeolmos 28130 Madrid, Spain
| | - Jens Nielsen
- Technical University of Denmark, National Veterinary Institute (DTU VET), 1870 Frederiksberg C and 4771 Kalvehave, Denmark.,Statens Serum Institut, 5 Artillerivej, Copenhagen 2300, Denmark
| | - Maria Montoya
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain.,The Pirbright Institute, Surrey GU24 0NF, UK
| |
Collapse
|
36
|
Krog JS, Hjulsager CK, Larsen MA, Larsen LE. Triple-reassortant influenza A virus with H3 of human seasonal origin, NA of swine origin, and internal A(H1N1) pandemic 2009 genes is established in Danish pigs. Influenza Other Respir Viruses 2017; 11:298-303. [PMID: 28245096 PMCID: PMC5410721 DOI: 10.1111/irv.12451] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [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] [Accepted: 02/14/2017] [Indexed: 01/15/2023] Open
Abstract
This report describes a triple‐reassortant influenza A virus with a HA that resembles H3 of human seasonal influenza from 2004 to 2005, N2 from influenza A virus already established in swine, and the internal gene cassette from A(H1N1)pdm09 has spread in Danish pig herds. The virus has been detected in several Danish pig herds during the last 2‐3 years and may possess a challenge for human as well as animal health.
Collapse
Affiliation(s)
- Jesper Schak Krog
- National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark
| | | | | | - Lars Erik Larsen
- National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark
| |
Collapse
|
37
|
Abstract
Purpose: To investigate the general toxicology of mangafodipir trisodium (MnDPDP, Teslascan). Material and Methods: Studies were performed in accordance with standard methods and in compliance with regulations current at the time of conduct. Results: Single-dose studies in rodents and dogs showed that MnDPDP was tolerated at doses of approximately 2000 μmol/kg, approximately 400 times a single imaging dose of 5 μmol/kg. The single dose tolerance of MnDPDP was approximately 10 times greater than MnCl2. A good safety profile of MnDPDP was also shown in repeat-dose studies (3 weeks), in which the no-observed-adverse-effect level for the rat, monkey and dog was 116, 29 and 10 μmol/kg, respectively. The local tolerance studies indicated that no adverse local tissue reactions are likely to occur after i.v. injection. Other studies indicate that accidental spillage of MnDPDP onto the skin is not expected to lead to significant systemic exposure, or to local irritation or hypersensitivity. MnDPDP was not genotoxic in a battery of several different tests. Conclusion: MnDPDP was shown to have a good safety profile suitable as an hepatobiliary MR contrast agent for i.v. administration.
Collapse
|
38
|
Henritzi D, Zhao N, Starick E, Simon G, Krog JS, Larsen LE, Reid SM, Brown IH, Chiapponi C, Foni E, Wacheck S, Schmid P, Beer M, Hoffmann B, Harder TC. Rapid detection and subtyping of European swine influenza viruses in porcine clinical samples by haemagglutinin- and neuraminidase-specific tetra- and triplex real-time RT-PCRs. Influenza Other Respir Viruses 2016; 10:504-517. [PMID: 27397600 PMCID: PMC5059951 DOI: 10.1111/irv.12407] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2016] [Indexed: 12/26/2022] Open
Abstract
Background A diversifying pool of mammalian‐adapted influenza A viruses (IAV) with largely unknown zoonotic potential is maintained in domestic swine populations worldwide. The most recent human influenza pandemic in 2009 was caused by a virus with genes originating from IAV isolated from swine. Swine influenza viruses (SIV) are widespread in European domestic pig populations and evolve dynamically. Knowledge regarding occurrence, spread and evolution of potentially zoonotic SIV in Europe is poorly understood. Objectives Efficient SIV surveillance programmes depend on sensitive and specific diagnostic methods which allow for cost‐effective large‐scale analysis. Methods New SIV haemagglutinin (HA) and neuraminidase (NA) subtype‐ and lineage‐specific multiplex real‐time RT‐PCRs (RT‐qPCR) have been developed and validated with reference virus isolates and clinical samples. Results A diagnostic algorithm is proposed for the combined detection in clinical samples and subtyping of SIV strains currently circulating in Europe that is based on a generic, M‐gene‐specific influenza A virus RT‐qPCR. In a second step, positive samples are examined by tetraplex HA‐ and triplex NA‐specific RT‐qPCRs to differentiate the porcine subtypes H1, H3, N1 and N2. Within the HA subtype H1, lineages “av” (European avian‐derived), “hu” (European human‐derived) and “pdm” (human pandemic A/H1N1, 2009) are distinguished by RT‐qPCRs, and within the NA subtype N1, lineage “pdm” is differentiated. An RT‐PCR amplicon Sanger sequencing method of small fragments of the HA and NA genes is also proposed to safeguard against failure of multiplex RT‐qPCR subtyping. Conclusions These new multiplex RT‐qPCR assays provide adequate tools for sustained SIV monitoring programmes in Europe.
Collapse
Affiliation(s)
- Dinah Henritzi
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute (FLI), Greifswald-Insel Riems, Germany
| | - Na Zhao
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute (FLI), Greifswald-Insel Riems, Germany
| | - Elke Starick
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute (FLI), Greifswald-Insel Riems, Germany
| | - Gaelle Simon
- Anses, Ploufragan-Plouzané Laboratory, Swine Virology Immunology Unit, Ploufragan, France
| | - Jesper S Krog
- National Veterinary Institute; Technical University of Denmark (DTU), Frederiksberg C, Denmark
| | - Lars Erik Larsen
- National Veterinary Institute; Technical University of Denmark (DTU), Frederiksberg C, Denmark
| | - Scott M Reid
- Department of Virology, Animal and Plant Health Agency-Weybridge, New Haw, Addlestone, Surrey, UK
| | - Ian H Brown
- Department of Virology, Animal and Plant Health Agency-Weybridge, New Haw, Addlestone, Surrey, UK
| | - Chiara Chiapponi
- Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Parma, Italy
| | - Emanuela Foni
- Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Parma, Italy
| | | | | | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute (FLI), Greifswald-Insel Riems, Germany
| | - Bernd Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute (FLI), Greifswald-Insel Riems, Germany
| | - Timm C Harder
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute (FLI), Greifswald-Insel Riems, Germany.
| |
Collapse
|
39
|
Antunes ACL, Halasa T, Lauritsen KT, Kristensen CS, Larsen LE, Toft N. Spatial analysis and temporal trends of porcine reproductive and respiratory syndrome in Denmark from 2007 to 2010 based on laboratory submission data. BMC Vet Res 2015; 11:303. [PMID: 26689831 PMCID: PMC4687366 DOI: 10.1186/s12917-015-0617-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 12/16/2015] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Porcine reproductive and respiratory syndrome (PRRS) has been a cause for great concern to the Danish pig industry since it was first diagnosed in 1992. The causative agent of PRRS is an RNA virus which is divided into different genotypes. The clinical signs, as well as its morbidity and mortality, is highly variable between herds and regions. Two different genotypes of PRRS virus (PRRSV) are found in Denmark: type 1 and type 2. Approximately 40% of Danish swine herds are seropositive for one or both PRRSV types. The objective of this study was to describe the temporal trend and spatial distribution of PRRSV in Danish swine herds from 2007 to 2010, based on type-specific serological tests from the PRRS surveillance and control program in Denmark using the results stored in the information management system at the National Veterinary Institute, Technical University of Denmark (DTU Vet). RESULTS The average monthly seroprevalence of PRRSV type 1 was 9% (minimum of 5%; maximum of 13%) in breeding herds, and 20% (minimum of 14%; maximum of 26%) in production herds; PRRSV type 2 had an average seroprevalence of 3% (minimum of 1%; maximum of 9%) in breeding herds and of 9% (minimum of 5%; maximum of 13%) within production herds. The seroconversion rate followed a similar and consistent pattern, being higher for type 1 than for type 2 for both PRRSV types. Regarding the spatiotemporal results, the relative risk distribution maps changed over time as a consequence of the changes in PRRSV seroprevalence, suggesting a general decline in the extent of areas with higher relative risk for both type 1 and 2. Local spatial analysis results demonstrated the existence of statistically significant clusters in areas where the relative risk was higher for both herds. CONCLUSIONS PRRSV type 1 seroprevalence was constantly higher than for PRRSV type 2 in both herd types. Significant spatial clusters were consistently found in Denmark, suggesting that PRRSV is endemic in these areas. Furthermore, relative risk distribution maps revealed different patterns over time as a consequence of the changes in seroprevalence.
Collapse
Affiliation(s)
- Ana Carolina Lopes Antunes
- Section for Epidemiology, National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1870, Frederiksberg C, Denmark.
| | - Tariq Halasa
- Section for Epidemiology, National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1870, Frederiksberg C, Denmark.
| | - Klara Tølbøl Lauritsen
- Section for Diagnostic and Scientific Advice, National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1870, Frederiksberg C, Denmark.
| | | | - Lars Erik Larsen
- Section for Virology, National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1870, Frederiksberg C, Denmark.
| | - Nils Toft
- Section for Epidemiology, National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1870, Frederiksberg C, Denmark.
| |
Collapse
|
40
|
Abstract
Housing preweaned dairy calves in pairs rather than individually has been found to positively affect behavioral responses in novel social and environmental situations, but concerns have been raised that close contact among very young animals may impair their health. In previous studies, the level of social contact permitted in individual housing has been auditory, visual, or physical contact. It is unclear how these various levels of social contact compare with each other and to pair housing, when their effects on behavior and health are considered, and whether the timing of pair housing has an effect. To investigate this, 110 Holstein calves (50 males, 60 females) in 11 blocks were paired according to birth date. Within 60 h of birth, each pair of calves was allocated to 1 of 5 treatments: individual housing with auditory contact (I), individual housing with auditory and visual contact (V), individual housing with auditory, visual, and tactile contact (T), pair housing (P), or individual housing with auditory and visual contact the first 2 wk followed by pair housing (VP). At 6 wk of age, calves were subjected to a social test and a novel environment test. In the social test, all pair-housed calves (P and VP) had a shorter latency to sniff an unfamiliar calf than did individually housed calves (I, V, and T), whereas calves with physical contact (T, P, and VP) sniffed the unfamiliar calf for longer than calves on the remaining treatments (I and V). In the novel environment test, calves with physical contact (T, P, and VP) had a lower heart rate, and more of these calves vocalized during the test compared with calves without physical contact (I and V). No effect of treatment was found for clinical scores, levels of the 5 most common pathogens in feces, or in development of serum antibodies against the 3 most common respiratory pathogens. Calves housed individually are more fearful of unfamiliar calves than are pair-housed calves. Contrary to common belief, the allowance of physical contact and pair housing had no effects on the health of the calves.
Collapse
Affiliation(s)
- Margit Bak Jensen
- Department of Animal Science, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark.
| | - Lars Erik Larsen
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, DK-1870 Frederiksberg C, Denmark
| |
Collapse
|
41
|
Trebbien R, Chriel M, Struve T, Hjulsager CK, Larsen G, Larsen LE. Wildlife reservoirs of canine distemper virus resulted in a major outbreak in Danish farmed mink (Neovison vison). PLoS One 2014; 9:e85598. [PMID: 24454897 PMCID: PMC3890312 DOI: 10.1371/journal.pone.0085598] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 11/28/2013] [Indexed: 12/11/2022] Open
Abstract
A major outbreak of canine distemper virus (CDV) in Danish farmed mink (Neovison vison) started in the late summer period of 2012. At the same time, a high number of diseased and dead wildlife species such as foxes, raccoon dogs, and ferrets were observed. To track the origin of the outbreak virus full-length sequencing of the receptor binding surface protein hemagglutinin (H) was performed on 26 CDV's collected from mink and 10 CDV's collected from wildlife species. Subsequent phylogenetic analyses showed that the virus circulating in the mink farms and wildlife were highly identical with an identity at the nucleotide level of 99.45% to 100%. The sequences could be grouped by single nucleotide polymorphisms according to geographical distribution of mink farms and wildlife. The signaling lymphocytic activation molecule (SLAM) receptor binding region in most viruses from both mink and wildlife contained G at position 530 and Y at position 549; however, three mink viruses had an Y549H substitution. The outbreak viruses clustered phylogenetically in the European lineage and were highly identical to wildlife viruses from Germany and Hungary (99.29% - 99.62%). The study furthermore revealed that fleas (Ceratophyllus sciurorum) contained CDV and that vertical transmission of CDV occurred in a wild ferret. The study provides evidence that wildlife species, such as foxes, play an important role in the transmission of CDV to farmed mink and that the virus may be maintained in the wild animal reservoir between outbreaks.
Collapse
Affiliation(s)
- Ramona Trebbien
- National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark
| | - Mariann Chriel
- National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark
| | | | | | - Gitte Larsen
- National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark
| | - Lars Erik Larsen
- National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark
- * E-mail:
| |
Collapse
|
42
|
Hansen MS, Segalés J, Fernandes LT, Grau-Roma L, Bille-Hansen V, Larsen LE, Nielsen OL. Detection of porcine circovirus type 2 and viral replication by in situ hybridization in primary lymphoid organs from naturally and experimentally infected pigs. Vet Pathol 2013; 50:980-8. [PMID: 23482522 DOI: 10.1177/0300985813480805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Porcine circovirus type 2 (PCV2) infection is the cause of postweaning multisystemic wasting syndrome (PMWS). It has been speculated whether cell types permissive of replication are found in the primary lymphoid organs and whether infection of these tissues has an important role in the pathogenesis of PMWS. The aim of this study was to determine if primary lymphoid organ cells support viral replication during PCV2 infection. This was done by histopathological examination of thymus and bone marrow from pigs experimentally inoculated with PCV2 (n = 24), mock-infected pigs (n = 12), pigs naturally affected by PMWS (n = 33), and age-matched healthy control animals (n = 29). In situ hybridization (ISH) techniques were used to detect PCV2 nucleic acid irrespective of replicative status (complementary probe, CP) or to detect only the replicative form of the virus (replicative form probe, RFP). PCV2 was not detected in the experimentally PCV2-inoculated pigs or the control animals. Among the PMWS-affected pigs, 19 of 20 (95%) thymuses were positive for PCV2 by CP ISH, and 7 of 19 (37%) of these also supported viral replication. By CP ISH, PCV2 was detected in 16 of 33 (48%) bone marrow samples, and 5 of 16 (31%) of these also supported replication. The 2 ISH probes labeled the same cell types, which were histiocytes in both organs and lymphocytes in thymus. The RFP labeled fewer cells than the CP. Thus, PCV2 nucleic acids and replication were found in bone marrow and thymus of PMWS-affected pigs, but there was no evidence that primary lymphoid organ cells are major supporters of PCV2 replication.
Collapse
Affiliation(s)
- M S Hansen
- Department of Veterinary Diagnostics and Research, The National Veterinary Institute, Technical University of Denmark (DTU), Bülowsvej 27, DK-1870 Frederiksberg C, Denmark.
| | | | | | | | | | | | | |
Collapse
|
43
|
Hjulsager CK, Breum SØ, Trebbien R, Handberg KJ, Therkildsen OR, Madsen JJ, Thorup K, Baroch JA, DeLiberto TJ, Larsen LE, Jørgensen PH. Surveillance for Avian Influenza Viruses in Wild Birds in Denmark and Greenland, 2007–10. Avian Dis 2012; 56:992-8. [DOI: 10.1637/10190-041012-resnote.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
44
|
Pedersen KS, Skrubel R, Stege H, Angen Ø, Ståhl M, Hjulsager C, Larsen LE, Nielsen JP. Association between average daily gain, faecal dry matter content and concentration of Lawsonia intracellularis in faeces. Acta Vet Scand 2012; 54:58. [PMID: 23013807 PMCID: PMC3533900 DOI: 10.1186/1751-0147-54-58] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 09/18/2012] [Indexed: 11/16/2022] Open
Abstract
Background The objective of this study was to investigate the association between average daily gain and the number of Lawsonia intracellularis bacteria in faeces of growing pigs with different levels of diarrhoea. Methods A longitudinal field study (n = 150 pigs) was performed in a Danish herd from day 29 to 47 post weaning. Every third day all pigs were weighed, subjected to a clinical examination and faecal samples were obtained. Faecal samples were subjected to dry matter determination and absolute quantification by PCR for L. intracellularis and porcine circovirus type 2 (PCV2). Association between average daily gain, faecal dry matter content, numbers of L. intracellularis bacteria and PCV2 genome copies in faeces was investigated in a multilevel mixed-effects linear model. Results Increasing numbers of L. intracellularis log10 bacteria/g faeces were significantly associated with decreasing average daily gain (P < 0.001). The association was decreasing with increasing faecal dry matter content (P < 0.01). The number of PCV2 log10 copies/g faeces was not significantly associated with average daily gain of the pigs (P > 0.5). Conclusion The results suggest a potential application of a PCR quantifying L. intracellularis in growing pigs. Faecal dry matter content must be taken into consideration in interpretation of such test results.
Collapse
|
45
|
Pedersen KS, Pedersen KH, Hjulsager C, Larsen LE, Ståhl M, Stege H, Angen Ø, Nielsen JP. Within-day repeatability for absolute quantification of Lawsonia intracellularis bacteria in feces from growing pigs. J Vet Diagn Invest 2012; 24:968-70. [PMID: 22786973 DOI: 10.1177/1040638712452111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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
Absolute quantification of Lawsonia intracellularis by real-time polymerase chain reaction (PCR) is now possible on a routine basis. Poor repeatability of quantification can result in disease status misclassification of individual pigs when a single fecal sample is obtained. The objective of the current study was to investigate overall variation within a day for fecal numbers of L. intracellularis bacteria determined by real-time PCR in growing pigs. From each of 30 pigs with an infection of L. intracellularis, 5 fecal samples were collected within 1 day. A total of 150 fecal samples were obtained and subjected to quantitative PCR (qPCR) testing. Mean fecal dry matter content was 14.3% (standard deviation = 4.5%). Two pigs (6.7%) alternated between being L. intracellularis qPCR positive and negative. For 28 pigs, the excreting levels of L. intracellularis were within the dynamic range of the qPCR assay at all sampling points. For these 28 pigs, the mean excretion level of L. intracellularis was 6.1 log(10) bacteria/g feces (standard deviation = 1.2 log(10) bacteria/g feces). The maximum observed difference between 2 fecal samples from the same pig was 1.1 log(10) bacteria/g feces. The average standard deviation for individual pigs was 0.27 log(10) bacteria/g feces. The average coefficient of variation within pigs was 0.04, ranging from 0.006 to 0.08. The results imply that absolute quantification of L. intracellularis by qPCR has acceptable repeatability within 1 day. However, a population-specific proportion of pigs alternating between positive and negative test results must be expected.
Collapse
Affiliation(s)
- Ken Steen Pedersen
- Department of Large Animal Sciences, University of Copenhagen, Groennegaardsvej 2, DK-1870 Frederiksberg C, Denmark.
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Kristensen CS, Bækbo P, Bille-Hansen V, Bøtner A, Vigre H, Enøe C, Larsen LE. Induction of porcine post-weaning multisystemic wasting syndrome (PMWS) in pigs from PMWS unaffected herds following mingling with pigs from PMWS-affected herds. Vet Microbiol 2009; 138:244-50. [DOI: 10.1016/j.vetmic.2009.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 03/10/2009] [Accepted: 04/03/2009] [Indexed: 11/29/2022]
|
47
|
Dupont K, Hjulsager CK, Kristensen CS, Baekbo P, Larsen LE. Transmission of different variants of PCV2 and viral dynamics in a research facility with pigs mingled from PMWS-affected herds and non-affected herds. Vet Microbiol 2009; 139:219-26. [PMID: 19576705 DOI: 10.1016/j.vetmic.2009.06.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 05/27/2009] [Accepted: 06/03/2009] [Indexed: 11/29/2022]
Abstract
Post-weaning Multisystemic Wasting Syndrome (PMWS) has been identified in most swine-producing countries worldwide. The disease has resulted in significant health challenges and economic damage to the swine industry. The aim of this study was to determine horizontal transmission of porcine circovirus type 2 (PCV2) and to examine viral dynamics in pigs in a controlled PMWS transmission study. In the study pigs from PMWS-affected herds and non-affected herds were permitted to have close contact (same pen), nose-to-nose contact (to pigs in neighbouring pens) or no physical contact (pen across the aisle and pens in other compartments). By DNA sequence analysis, eight variants of genotype PCV-2b were identified in the research facility. From the spread of these PCV2-variants it was concluded that PCV2 primarily infects through close contact and nose-to-nose contact. PCV2 genome sequences were obtained from selected pigs at arrival to the research facility and again when the same pigs developed PMWS. This analysis showed that pigs from PMWS-affected herds developed PMWS caused by the same variant of PCV2 as they carried when entering the research facility. In contrast, pigs from non-affected herds developed PMWS with PCV2-variants identified in pigs from PMWS-affected herds. This was probably connected to at least 10(3) higher mean serum-titer of PCV2 in pigs from PMWS-affected herds as compared to pigs from non-affected herds at the beginning of the transmission study. The study further showed that pigs able to control the PCV2 infection, as measured by the PCV2-titer in serum, recovered clinically (pigs from PMWS-affected herds) or stayed healthy (pigs from non-affected herds). Like this, pigs with a PCV2 titer below 5x10(8) copies/ml serum during the study period had a chance of recover from the PCV2 infection whereas pigs with PCV2 titers above 5x10(8) copies/ml serum at any time point generally died from PMWS.
Collapse
Affiliation(s)
- K Dupont
- National Veterinary Institute, The Technical University of Denmark, DK-1790 Copenhagen V, Denmark.
| | | | | | | | | |
Collapse
|
48
|
Norder H, Sundqvist L, Magnusson L, Østergaard Breum S, Löfdahl M, Larsen LE, Hjulsager CK, Magnius L, Böttiger BE, Widén F. Endemic hepatitis E in two Nordic countries. ACTA ACUST UNITED AC 2009; 14. [PMID: 19442399 DOI: 10.2807/ese.14.19.19211-en] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Antibodies against hepatitis E virus (anti-HEV) were found in 248 Swedish and Danish patients between 1993 and 2007. Most patients were symptomatic and tested for anti-HEV due to travel abroad. Among patients with known country of infection, most were infected in Asia, mainly on the Indian subcontinent. However, 29 patients were infected in Europe, nine of these had HEV IgM and/or HEV RNA in serum. In sera from 65 of 141 tested patients HEV RNA could be detected, and 63 strains could be typed by limited sequencing within ORF2. HEV RNA was found in sera from 71% of the patients with HEV IgM and IgG and in 18% of the patients with only detectable HEV IgG. It was also found up to three weeks after the onset of disease in 67% of the patients with known date of onset. Patients infected in Europe were infected by genotype 3, and were older than those infected by genotype 1 (mean age 55.3 vs 30 years, p<0.001). Since it is known that genotype 3 can infect domestic pigs, HEV strains from 18 piglets in 17 herds in Sweden and Denmark were sequenced. Phylogenetic analyses of the genotype 3 strains showed geographical clades and high similarity between strains from patients and pigs from the same area. There are thus autochthonous hepatitis E cases in Scandinavia, and there are probably many undiagnosed ones. Patients with hepatitis of unknown etiology should therefore be investigated for anti-HEV even if they have not been outside Europe, since infections acquired from pigs or other animals should be taken into consideration.
Collapse
Affiliation(s)
- H Norder
- Department of Virology, Swedish Institute for Infectious Disease Control (Smittskyddsinstitutet, SMI), Solna, Sweden.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Grau-Roma L, Heegaard PMH, Hjulsager CK, Sibila M, Kristensen CS, Allepuz A, Piñeiro M, Larsen LE, Segalés J, Fraile L. Pig-major acute phase protein and haptoglobin serum concentrations correlate with PCV2 viremia and the clinical course of postweaning multisystemic wasting syndrome. Vet Microbiol 2009; 138:53-61. [PMID: 19356864 DOI: 10.1016/j.vetmic.2009.03.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 02/03/2009] [Accepted: 03/02/2009] [Indexed: 02/02/2023]
Abstract
The aim of the present longitudinal study was to assess the evolution of two acute phase proteins (APPs), pig-major acute phase protein (pig-MAP) and haptoglobin (HPT), in serum from pigs that developed postweaning multisystemic wasting syndrome (PMWS) in comparison to healthy and wasted non-PMWS affected pigs. In addition, evidence of infection with other pathogens and its relation with variations in APPs concentrations was also assessed. Fourteen independent batches of 100-154 pigs were monitored from birth to PMWS outbreak occurrence in 11 PMWS affected farms. Pigs displaying PMWS-like signs and age-matched healthy controls were euthanized during the clinical outbreak. PMWS was diagnosed according to internationally accepted criteria and pigs were classified as: (i) PMWS cases, (ii) wasted non-PMWS cases and (iii) healthy pigs. At the moment of PMWS occurrence, pig-MAP and HPT concentration in PMWS affected pigs were higher than in healthy ones (p<0.0001). No differences in APPs serum concentrations between subclinically PCV2-infected pigs and healthy non-PCV2-infected pigs (based on quantitative PCR on serum results) were detected. Results showed a significant correlation between PCV2 loads and both pig-MAP (R=0.487-0.602, p<0.0001) and HPT (R=0.326-0.550, p<0.05-0.0001) concentrations in serum of PMWS affected pigs, indicating that the acute phase response in PMWS affected pigs occurred concomitantly to PCV2 viremia. No other pathogen, apart from PCV2, was consistently related with variations in APPs concentrations. A ROC analysis, made to determine the capacity of discrimination of both APPs between PMWS affected and non-affected pigs, showed higher sensitivity and specificity values using pig-MAP compared to HPT. These results suggest that pig-MAP might be a better indicator of PMWS status than HPT. Moreover, the fact that APR occurred some weeks before the start of clinical signs suggests that APPs could provide valuable prognostic information for PMWS development.
Collapse
Affiliation(s)
- L Grau-Roma
- Centre de Recerca en Sanitat Animal, UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Angen O, Thomsen J, Larsen LE, Larsen J, Kokotovic B, Heegaard PMH, Enemark JMD. Respiratory disease in calves: microbiological investigations on trans-tracheally aspirated bronchoalveolar fluid and acute phase protein response. Vet Microbiol 2009; 137:165-71. [PMID: 19186010 PMCID: PMC7117372 DOI: 10.1016/j.vetmic.2008.12.024] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 12/17/2008] [Accepted: 12/29/2008] [Indexed: 11/02/2022]
Abstract
Trans-tracheal aspirations from 56 apparently healthy calves and 34 calves with clinical signs of pneumonia were collected in six different herds during September and November 2002. The 90 samples were cultivated and investigated by PCR tests targeting the species Histophilus somni, Mannheimia haemolytica, Pasteurella multocida, Mycoplasma bovis, Mycoplasma dispar, and Mycoplasma bovirhinis. A PCR test amplifying the lktC-artJ intergenic region was evaluated and shown to be specific for the two species M. haemolytica and Mannheimia glucosida. All 90 aspirations were also analyzed for bovine respiratory syncytial virus (BRSV), parainfluenza-3 virus, and bovine corona virus by antigen ELISA. Surprisingly, 63% of the apparently healthy calves harbored potentially pathogenic bacteria in the lower respiratory tract, 60% of these samples contained either pure cultures or many pathogenic bacteria in mixed culture. Among diseased calves, all samples showed growth of pathogenic bacteria in the lower respiratory tract. All of these were classified as pure culture or many pathogenic bacteria in mixed culture. A higher percentage of the samples were positive for all bacterial species in the group of diseased animals compared to the clinically healthy animals, however this difference was only significant for M. dispar and M. bovirhinis. M. bovis was not detected in any of the samples. BRSV was detected in diseased calves in two herds but not in the clinically healthy animals. Among the diseased calves in these two herds a significant increase in haptoglobin and serum amyloid A levels was observed compared to the healthy calves. The results indicate that haptoglobin might be the best choice for detecting disease under field conditions. For H. somni and M. haemolytica, a higher percentage of the samples were found positive by PCR than by cultivation, whereas the opposite result was found for P. multocida. Detection of P. multocida by PCR or cultivation was found to be significantly associated with the disease status of the calves. For H. somni a similar association with disease status was only observed for cultivation and not for PCR.
Collapse
Affiliation(s)
- Oystein Angen
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, DK-1790 Copenhagen V, Denmark.
| | | | | | | | | | | | | |
Collapse
|