segunda-feira, 8 de julho de 2013
BOVINE TUBERCULOSIS - UK: (ENGLAND), CONTROL
A ProMED-mail post
ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>
Date: Thu 4 Jul 2013
Source: DEFRA (UK Department for Environment, Food & Rural Affairs) press release [edited] <https://www.gov.uk/government/news/bovine-tb-strategy-launched-to-make-england-disease-free-within-25-years>
A plan to rid England of bovine TB within 25 years has been set out today [4 Jul 2013] by Environment Secretary Owen Paterson.
The strategy sets out action in areas such as disease surveillance, pre- and post-movement cattle testing, removal of cattle exposed to bTB, tracing the potential source of infection and wildlife controls including culling and vaccination trials.
It also focuses on the development of new techniques such as badger and cattle vaccines and new diagnostic tests that could one day offer new ways of tackling the disease.
Launching the strategy Mr Paterson said: "28 000 otherwise healthy cattle were slaughtered last year  because of bovine TB. Today [4 Jul 2013], we start a countdown towards an England free from this terrible disease. We must stop bTB spreading into previously unaffected areas while bringing it under control in places where it has taken hold. I have visited Australia, New Zealand, the Republic of Ireland and the USA, and we must learn from their successful TB eradication programmes."
"Bovine TB is the most pressing animal health problem in the UK. It threatens our cattle farmers' livelihoods and our farming industry as well as the health of wildlife and livestock. We must all work together to become TB free within 25 years."
The strategy follows up measures already in place and includes comprehensive packages tailored to 3 distinct risk areas across England.
The strategy aims to:
- Preserve the low risk of TB in the north and east of England;
- Stop and reverse the spread of bovine TB at the frontier of the
disease, known as the edge area; and - Reduce the level of infection in the high risk area, mainly in the south west.
Defra is working with the farming industry to introduce risk-based trading to help them make more informed decisions about the cattle they buy. A range of crucial TB risk information such as movement and testing history will be shared at the point of sale so farmers will know the animal's TB testing history before purchase.
Chairman of the Animal Health and Welfare Board for England Michael Seals said: "The draft strategy is the outcome of collaboration between government and industry with one aim: to achieve bTB free status for England. Ongoing collaboration and investment by both parties will be essential to develop and deploy the necessary means to achieve this aim."
The strategy, which has been developed by the Animal Health and Welfare Board for England (AHWBE) and the Bovine Tuberculosis Eradication Advisory Group for England (TBEAG) draws extensively on experiences in countries such as Australia, New Zealand, USA and the Republic of Ireland, all of which have shown the way to successfully tackle bovine TB through addressing the infection in cattle and in wildlife.
A crucial element is a consideration of options for governance, delivery and funding of the Strategy. The New Zealand experience in particular demonstrates the significant potential benefits of having a robust government-industry partnership approach to tackling bTB.
[Links, at the source URL:
1. Draft strategy and consultation
2. Infographic on the strategy
3. Audio: News clips of Owen Paterson speaking about bovine TB].
[The following appendix linked to the press release, titled "Controlling bovine tuberculosis in badgers," may be of interest to subscribers:
"Bovine TB is mainly a disease of cattle, but it can also affect other species. We know that the disease is present in badgers in parts of England and that the disease can be transmitted among cattle, among badgers, and between the 2 species.
Areas of England where there is a high incidence of bovine TB in cattle also tend to have high numbers of badgers. The scientific evidence shows conclusively that badgers contribute significantly to bovine TB in cattle. This evidence comes from the randomised badger culling trial. In this trial, there were positive and negative changes in the incidence of TB in cattle as a result of badger culling.
The relationship between TB in badgers and in cattle is highly complex. The following articles give more information about this relationship:
1. Guardian Online article by Chief Scientist Ian Boyd and Chief Veterinary Officer Nigel Gibbens explain the science behind the badger cull [see at <http://www.guardian.co.uk/environment/2012/oct/11/badger-cull-furore>].
2. Conclusions from a meeting held between Professor Bob Watson and scientific experts on 4 Apr 2011; see at <http://archive.defra.gov.uk/foodfarm/farmanimal/diseases/atoz/tb/documents/bovinetb-scientificexperts-110404.pdf>.
The following BBE-News report may add useful details. - Mod.AS]
Date: 4 Jul 2013
Source: BBC News [summarised, edited] <http://www.bbc.co.uk/news/science-environment-23162183?print=true>
Ministers have set out their long-term plans for fighting TB in cattle, aiming for England to become TB-free within 25 years.
Cases of bovine TB have risen in parts of England and Wales over the past 2 decades.
Plans include a controversial cull of badgers, due to start this year  in 2 areas of South West England. But the draft strategy published on Thu [4 Jul 2013] said that "further research into alternative population control methods (e.g. sett-based culling methods and non-lethal methods) is also under consideration."
That could include injecting badger setts, or dens, with gases or gas-laden foam that displace oxygen, and "proof-of-principle" experiments are being carried out into the use of contraceptives.
Launching the strategy, Mr Paterson said: "Bovine TB is the most pressing animal health problem in the UK. It threatens our cattle farmers' livelihoods and our farming industry as well as the health of wildlife and livestock.
Bovine TB is an infectious disease that mainly affects cattle. It also infects other animals, including the badger. Cattle with bovine TB are most often identified through testing using the tuberculin skin test before they develop obvious signs of the disease. This is because the disease usually progresses slowly, and it can take some time for clinical signs to appear. When TB breaks out in a herd, affected cows are destroyed, and movement restrictions are placed on a farm. The English and Welsh governments estimate they have spent BP 500 million [USD 744 million] in the last decade on testing, compensation and research.
The government's policy to control bovine TB has been a matter of much debate, because of its implications for the farming industry and because one option is to cull badgers.
Badger culling has been authorised at 2 pilot sites in West Somerset and in and around West Gloucestershire.
Under the proposals, about 5000 badgers will be culled by free shooting before the end of the year . Ministers say the action is needed to help tackle the cattle disease, which has been steadily rising since the 1980s.
Campaigners against the cull say it will have no impact on bovine TB and could lead to local populations of badgers being wiped out.
The strategy sets out action in areas including:
- Disease surveillance,
- Pre- and post-movement cattle testing,
- Removal of cattle exposed to bovine TB,
- Tracing the potential source of infection,
- Wildlife controls including culling and vaccination trials.
It also focuses on the role of badger and cattle vaccines and diagnostic tests that could one day offer new ways of tackling the disease.
Vaccination of badgers is already underway in Wales as an alternative to culling. A similar vaccine for cattle exists, but its use is prohibited by EU regulations.
Scotland has been officially TB free since 2009.
Farming Minister David Heath said there was no single answer to the problem of TB in England.
25 years to wipe out TB in cattle seems like a long-time, but in many ways it's an ambitious target. As one scientist put it, there are no quick fixes. Experience around the world has shown that once TB has become established in populations of domestic and wild animals, measures to control it are both costly and difficult.
Australia is one of the few countries to have successfully eradicated TB in cattle and wild water buffalo, a process which took 27 years. The government's long term strategy for the control of bovine TB in England contains no startling new revelations but pulls together various strands and policies involving the government, the farming industry, vets and scientists. It also focuses on the idea of dividing England into 3 areas -- low risk, high risk and the edge between the 2 areas -- and tackling each area with different interventions. A key hurdle in the coming months is the reaction of farmers, who will inevitably bear some of the costs of the new strategy.
He told the BBC: "We know that we have a badger population which has TB and is infecting both other badgers and cattle in the same way that cattle are infecting badgers. So we've got this cycle there; we need to break that cycle. Culling is part of that process because that deals with the infected badger, and no other measure I'm afraid deals with badgers which are already infected. You can't vaccinate a badger and remove the infection. But we also need to protect the healthy badgers."
He said research was underway to better identify which badgers are infected with TB and which are not. Experts are also developing an oral badger vaccine against TB, which the government hopes to deploy in 2019.
The farming minister added: "We shall be using those vaccines, as we are already, but increasingly so, particularly on the edge areas of infection so that we're protecting clean badger populations from infection and, therefore, stopping the spread of the disease. I think if we put all those things together, then we can achieve our objective, which is healthy cattle and healthy badgers living side by side."
On Thursday [4 Jul 2013], scientists released a document setting out the scientific evidence for and against culling badgers, following concern that data on badger culling is being misrepresented by both sides of the debate.
Charles Godfray of the Oxford Martin School at the University of Oxford, co-author of the Natural Science Evidence Base for Control of Bovine TB study, said: "Agreeing on what the science says is important, because it means everyone can discuss the topic based on a shared evidence base. The assumptions upon which policy is based, and the expectations about its results, must also be consistent with what the science tells us."
Professor Robbie McDonald, chair in the Natural Environment, Environment and Sustainability Institute at the University of Exeter added: "I welcome the government's recognition that 25 years of hard work lies ahead. There are no quick fixes here, and it would take 25 years to get to TB free status, even if everyone agreed what to do. There are deep-seated conflicts and divisions of opinion over what to do about badgers, and effective intervention in the wildlife component of the TB problem needs support from government, industry and the wider public."
[Byline: Helen Briggs]
[Although bovine tuberculosis was once disseminated worldwide, control programs have eliminated or nearly eliminated this disease from domesticated animals in many countries. Nations currently classified as tuberculosis-free include Australia, Iceland, Denmark, Sweden, Norway, Finland, Austria, Switzerland, Luxembourg, Latvia, Slovakia, Lithuania, Estonia, the Czech Republic, Canada, Singapore, Jamaica, Barbados and Israel. Eradication is in progress in other European countries, Japan, New Zealand, the United States, Mexico, and some countries of Central and South America.
Only "test-and-slaughter" techniques are guaranteed to eradicate tuberculosis from domesticated animals. Affected herds are re-tested periodically to eliminate cattle that may shed the organism; the tuberculin test is generally used. Infected herds are usually quarantined, and animals that have been in contact with reactors are traced.
Eradication efforts are complicated when _M. bovis_ infection is not limited to bovines but involves also other species, particularly wildlife such as badgers in the UK and possums/cervids in New Zealand. Culling to reduce the population density can decrease transmission. According to some views, culling may have unanticipated effects such as increasing the dispersal of the remaining members of a species. Links to information sources addressing the various aspects of the bTB situation in England, its control attempts, and accumulated results are accessible at the source URL. - Mod.AS
A HealthMap/ProMED-mail map can be accessed at: <http://healthmap.org/r/1lNY>.]
[see also: Bovine tuberculosis - UK: (England), spread 20130622.1787066 2012
Bovine tuberculosis - UK (04): (WAL, NIR) badger vaccination 20121130.1432082
Bovine tuberculosis - UK (03): (England) badger control 20120917.1296946
Bovine tuberculosis, human - UK (02): (England) ex alpaca 20120510.1128707
Bovine tuberculosis, alpaca - UK: immune system, RFI 20120430.1118567
Bovine tuberculosis, human - UK: (England) ex alpaca 20120427.1116358
Bovine tuberculosis - UK (02): (Scotland) 20120414.1101180
Bovine tuberculosis, cervid - UK: (England) 20120218.1045228
Bovine tuberculosis - UK: (England) badger control 20120121.1017815 2011
Bovine tuberculosis - UK: badger vaccination 20111014.3087
Bovine tuberculosis - UK: alpaca, mastitis, implications 20110825.2588
Bovine tuberculosis, bovine - UK (04): England 20110723.2219
Bovine tuberculosis - UK: (Wales) badger control 20110328.0969 2010
Tuberculosis - UK: resurgence 20101223.4522
Bovine tuberculosis - UK (05): badger vaccination 20101110.4082
Bovine tuberculosis - UK (04): new control program 20100921.3396]