Aetiology pathogenesis and immunology of post-weaning multi-systemic wasting syndrome in pigs: genetic-environmental interactions
Lead Research Organisation:
Royal Veterinary College
Department Name: Pathology and Pathogen Biology
Abstract
Post-weaning multi-systemic wasting syndrome (PMWS) is a common disease of young pigs in the U.K. It is extremely debilitating, causes considerable suffering and poor welfare, and has a high mortality of up to 20%. The disease was first recognised in 1991 and is now prevalent worldwide. Since over 1.2 billion pigs are reared annually for human consumption, then there are good commercial and ethical reasons why new diseases like PMWS should be controlled or eliminated to ensure a safe, humane and sustainable supply of pork, sausages and ham. At first scientists thought that PMWS was caused by a virus but they now realise that genetic and environmental factors must be involved, along with opportunistic secondary pathogens. This project proposes a unique interdisciplinary approach to investigate this endemic disease and will integrate modern scientific techniques from epidemiology, genetics, microbiology, pathology, molecular immunology and environmental science to identify why PMWS occurs, leading to new control methods. British pig farmers will be heavily involved in the project, thereby guaranteeing that pigs in Britain will be the first to benefit from this research, while collaboration with a major international pharmaceutical company will ensure that new veterinary products will be made available to pig farmers worldwide.
Technical Summary
Post-weaning multi-systemic wasting syndrome (PMWS) is considered to be a multifactorial disease, with porcine circovirus 2 (PCV2) suggested a necessary agent. Despite the fact that infected pigs seroconvert to PCV2, it is becoming increasingly evident that PCV2 is not the sole contributor, and that the host's genetic background, environment and opportunistic pathogen(s) play a crucial role in the pathogenesis of PMWS. Interestingly, infected pigs seem to harbour PCV2 in immune cells, despite no obvious viral replication or functional differences of infected cells. Once PMWS occurs, significant changes in the subpopulations of immune cells occur. These findings in PMWS-affected pigs suggest an inability to mount an effective immune response, although the mechanism(s) by which the immune system is altered is unclear. The present proposal is in three complementary parts. First, we will identify putative secondary pathogens in a case-control study on selected farms. This epidemiological study will also identify common environmental co-factors or triggers that lead to full clinical development of PMWS. Secondly, we will identify the molecular mechanisms of pathogenesis and the early replication effects of susceptible cells by using porcine-specific microarrays on cells generated from breeds with differing in susceptibility to PMWS. We will identify signalling pathways that are altered independently of cell type. By using cells generated from different breeds, we will identify molecules/pathways that are altered in specific breeds, and will aim to combine these analyses with subsequent genetic analysis. Thirdly, despite several attempts to re-create PMWS in vivo, no consistent experimental model of PMWS has been developed. Here, using the information generated in parts 1 and 2, we will attempt to develop an in vivo model of PMWS and use it to study the aetiology of PMWS including environmental and genetic risk factors and the involvement of secondary pathogens.
Publications
Wieland B
(2012)
Porcine circovirus type 2 infection before and during an outbreak of postweaning multisystemic wasting syndrome on a pig farm in the UK.
in The Veterinary record
Velasova M
(2012)
Risk factors for porcine reproductive and respiratory syndrome virus infection and resulting challenges for effective disease surveillance.
in BMC veterinary research
Velasova M
(2013)
Effectiveness of porcine circovirus type 2 vaccination in reducing the severity of post-weaning multisystemic wasting syndrome in pigs.
in Veterinary journal (London, England : 1997)
Tombácz K
(2014)
Lack of genetic diversity in newly sequenced porcine circovirus type 1 strains isolated 20 years apart.
in Genome announcements
Patterson R
(2015)
Exposure to environmental stressors result in increased viral load and further reduction of production parameters in pigs experimentally infected with PCV2b.
in Veterinary microbiology
Mavrommatis B
(2014)
Global gene expression profiling of myeloid immune cell subsets in response to in vitro challenge with porcine circovirus 2b.
in PloS one
Holt HR
(2011)
BPEX Pig Health Scheme: a useful monitoring system for respiratory disease control in pig farms?
in BMC veterinary research
Barbara Wieland (Author)
(2010)
Prevalence of endemic pig diseases in England: An overview six months into a large scale cross sectional study on post-weaning multisystemic wasting syndrome (PMWS)
in Pig Journal
Barbara Wieland (Author)
(2008)
Making sense of PMWS, PCV2, PCVD
Title | Aetiology, pathogenesis and immunology of PMWS |
Description | A voice-over of a presentation by Dr Barbara Wieland on the BPEX webpage, please see http://www.bpex.org.uk/downloads/300353/296959/PMWS%20RVC%20voice%20over%20presentation.ppsx |
Type Of Art | Film/Video/Animation |
Year Produced | 2008 |
Impact | no actual impacts realised to date |
URL | http://www.bpex.org.uk/downloads/300353/296959/PMWS%20RVC%20voice%20over%20presentation.ppsx |
Description | Any kind of stress aids viral replication; no additional pathogen is required |
Exploitation Route | Improve housing conditions and creating stress-free environment can reduce costs of PCV2 infection, and may actually prevent it |
Sectors | Agriculture Food and Drink |
URL | http://www.vettimes.co.uk/news/rvc-study-shows-environmental-stress-triggers-costly-pig-disease/ |
Description | Analysis of BPEX PCV2 post-vaccination data |
Amount | £32,500 (GBP) |
Organisation | British Pig Executive BPEX |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 02/2009 |
End | 08/2009 |
Description | Analysis of BPEX PCV2 post-vaccination data |
Amount | £32,500 (GBP) |
Organisation | British Pig Executive BPEX |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 02/2009 |
End | 08/2009 |
Description | Identification of the T-cell dependent vaccine response to recombinant PCV-2 antigens |
Amount | £85,076 (GBP) |
Organisation | Royal Veterinary College (RVC) |
Sector | Academic/University |
Country | United Kingdom |
Start | 09/2011 |
End | 09/2014 |
Description | Identification of the T-cell dependent vaccine response to recombinant PCV-2 antigens |
Amount | £85,076 (GBP) |
Organisation | Royal Veterinary College (RVC) |
Sector | Academic/University |
Country | United Kingdom |
Start | 09/2011 |
End | 09/2014 |
Title | PMWS economic model calculator |
Description | PMWS calculator to assess how much the disease cost to a specific farm and what are the most cost-efficient strategies on this farm. |
Type Of Material | Database/Collection of data |
Year Produced | 2013 |
Provided To Others? | No |
Impact | No actual impacts realised to date |
URL | http://www.bpex.org.uk/articles/303060 |
Title | PMWS severity estimation sheet |
Description | Estimation of Post-weaning Multi-systemic Wasting Syndrome (PMWS) severity that farmers can use for their farms. |
Type Of Material | Database/Collection of data |
Year Produced | 2011 |
Provided To Others? | No |
Impact | No actual impacts realised to date |
URL | http://www.bpex.org.uk/articles/300874 |
Description | Calculator counts the cost of pig disease |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | Yes |
Primary Audience | Participants in your research or patient groups |
Results and Impact | Press release to describe the the PMWS calculator which allows farmers to see just how much the disease, present in 99% of pig farms, has cost them. please see no actual impacts realised to date |
Year(s) Of Engagement Activity | 2013 |
URL | http://www.bbsrc.ac.uk/news/food-security/2013/130709-n-cost-of-pig-disease.aspx |
Description | From exotic to endemic: a new disease of pigs |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Participants in your research or patient groups |
Results and Impact | Description of severity indicators identified as part of the PMWS project Please see no actual impacts realised to date |
Year(s) Of Engagement Activity | 2010 |
URL | http://www.bbsrc.ac.uk/news/food-security/2010/101109-f-new-disease-pigs.aspx |
Description | New research suggests why some farms develop devastating pig disease |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | Yes |
Primary Audience | Participants in your research or patient groups |
Results and Impact | New research funded by the Biotechnology and Biological Sciences Research Council, published today (8 July), has identified the factors that make some farms more likely to develop an economically devastating pig disease. The disease, Post Weaning Multi-systemic Wasting Syndrome (PMWS), is estimated to cost the UK pig industry £30M each year. The research could help to outline best practice husbandry to enable farmers to optimise animal welfare and maintain production. Please see no actual impacts realised to date |
Year(s) Of Engagement Activity | 2011 |
URL | http://www.bbsrc.ac.uk/news/food-security/2011/110708-pr-devastating-pig-disease.aspx |
Description | PMWS and Risk Factors |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Primary Audience | Public/other audiences |
Results and Impact | A leaflet produced in collaboration with BPEX to inform farmers about the risk factors related to PMWS occurrence on farms Research into Action Flyer, which can be found here: no actual impacts realised to date |
Year(s) Of Engagement Activity | 2011 |
URL | http://www.bpex.org.uk/2ts/documents/RIA7PMWS.pdf |
Description | Pig disease research shows prevention strategy progress |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Article in "Veterinary Times" Article about latest PCV2 work funded through CEDFAS initiative Article in "Veterinary Times" (Vol. 44, No 14, page 4) no actual impacts realised to date |
Year(s) Of Engagement Activity | 2014 |
URL | http://www.xlvets.co.uk/press-articles/veterinary-times-vol-44-no-13 |
Description | Pig wasting syndrom costing farmers millions |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Participants in your research or patient groups |
Results and Impact | Description of the economical findings related to PMWS Please see no actual impacts realised to date |
Year(s) Of Engagement Activity | 2013 |
URL | http://www.bbsrc.ac.uk/news/food-security/2013/130326-pr-pig-wasting-syndrome.aspx |
Description | Press coverage of PLOSOne article |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Primary Audience | Media (as a channel to the public) |
Results and Impact | Press coverage of PLOSOne article no actual impacts realised to date |
Year(s) Of Engagement Activity | 2014 |
URL | http://www.farmingfutures.org.uk/blog/new-insights-pig-pmws-disease |
Description | Risk factors for PMWS: an on-going cross-sectional study in UK-pig farms |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Paper Presentation |
Geographic Reach | International |
Primary Audience | Participants in your research or patient groups |
Results and Impact | Seminar at the AHVLA-RVC research day no actual impacts realised to date |
Year(s) Of Engagement Activity | 2008 |
Description | Scientists gain insights into pig disease which costs farmers millions |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Participants in your research or patient groups |
Results and Impact | Scientists gain insights into pig disease which costs farmers millions no actual impacts realised to date |
Year(s) Of Engagement Activity | 2014 |