News Release:Tuesday 23 February 2010 Scientists celebrate double grant success to help tackle global food security Scientists at one of the world’s leading animal health research institutes are celebrating after being awarded grants totaling over £1 million to investigate two of the most prevalent, damaging and costly diseases of livestock worldwide. Parasitic worms are a major cause of production loss among sheep and goats in sub-tropical regions of India and Africa and Malignant Catarrhal fever is a fatal viral disease of cattle in Africa. Over the next three years animal scientists at Moredun Research Institute in Edinburgh will work with researchers around the world to develop practical and sustainable solutions to the challenges posed by these livestock diseases in developing countries. The first project involves Moredun scientists applying their existing knowledge about parasitic worm control in sheep and goats to situations in other parts of the world where these worms are also a major cause of production loss. Parasitic gut worm infections are conventionally controlled using drugs, but these are expensive for smallholder farmers in developing countries and increasingly worms are becoming resistant to these drugs. Researchers from Moredun will work in partnership with scientists in Bristol, Canada, India and South Africa to develop new ways for farmers to control parasitic worms in their animals and therefore safeguard their food security. The second project involves the testing of a vaccine for malignant catarrhal fever (MCF) which is a major concern to maasai farmers in Africa who rely on cattle for their economic and social welfare. MCF is a viral disease of many cloven hoofed animals. There is a wildebeest form of the virus that causes no harm to the wildebeest but causes a fatal disease in the cattle that graze alongside them on the African plains. Working with partners in Glasgow, Nottingham and Tanzania, Moredun researchers will test a potential MCF vaccine they have helped develop under field conditions in Tanzania. The above projects are two of sixteen that have been funded by a new £13 million initiative launched by the Biotechnology and Biological Sciences Research Council (BBSRC), the Department for International development (DFID) and the Scottish Government to help support farmers and families in developing countries. It is hoped that this new funding will help scientists reduce the devastating effect livestock disease can have on global food security and livelihoods. More than 900 million people in the developing world live below the poverty line in rural areas. Just one animal can meet a whole family's needs, but deadly and debilitating livestock diseases can jeopardise food security for these people and lead them into greater poverty. Moredun Research Institute is one of the top ten animal research institutes worldwide and its researchers are keen to work with collaborators to help find answers to global livestock problems. Professor Julie Fitzpatrick, Scientific Director of Moredun welcomed this initiative. She commented “Moredun is delighted to have the opportunity to work with partners in overseas institutes in order to help develop practical and sustainable solutions to the challenges posed by livestock diseases in developing countries. “ Richard Lochhead, Cabinet Secretary for Rural Affairs for the Scottish Government, said: "We are proud that our world class science base in animal health is helping to address such important global issues. The challenges are immense but by working together we can make a real difference to the long term prospects and wellbeing of communities throughout the world." Living with liver fluke 26th January 2010
Liver fluke disease (fasciolosis) is caused by the parasitic flatworm, Fasciola hepatica [Fig.1]. The parasite has a complicated 2-host life-cycle involving a mud snail intermediate host (in which the larval stages develop and multiply) and a mammalian definitive host (in which the adult fluke establish and lay eggs) [Fig.2]. The type of disease seen depends on the type of infection. Acute fluke is caused by the mass migration of juvenile fluke through the liver, whereas chronic fluke is caused by the accumulation of adult fluke in the bile ducts. Liver fluke disease costs the UK livestock industry many millions of pounds per year, mainly due to deaths from acute fluke and untreated chronic fluke and condemnation of affected livers at slaughter. The disease is particularly serious in sheep and can result in severe liver damage [Fig.3]; cattle are less clinically affected but still represent a significant source of infection for sheep on mixed grazing.
The disease is on the increase in the UK, in both sheep and cattle; we now see disease outside the traditional high risk periods and in previously fluke-free areas. A number of factors may be responsible for this. Recent changes in the climate e.g. increasing temperature and rainfall and a longer grazing season conspire to increase fluke transmission. There are increasing reports of flukicide resistance, especially to triclabendazole, the drug of choice for acute fluke. Increased movement of livestock (and their parasites) has served to spread infection into previously fluke-free areas. Finally, environmental change, especially the introduction of wetlands into grazing systems provides ideal habitats for snails and fluke.
Diagnosis of liver fluke disease is not straightforward. Faecal egg counts only detect chronic (adult) infections and results must be treated with caution since fluke egg shedding is spasmodic, thus a negative egg count may be obtained from stock still harbouring adult fluke. Suspect fluke cases can be investigated using immunological tests on faecal, blood or milk samples and/or biochemical tests to detect liver and/or bile duct damage. Also, abattoirs may be able to supply post mortem information about the fluke status of animals sent for slaughter.
Grazing management can help reduce exposure of livestock to fluke as can drainage of heavy, low-lying pasture. However, the main way to treat liver fluke disease is through strategic drenching with a flukicidal drug. There are a number of such products on the market, though they differ in what age of parasite they are active against. Traditionally, fluke treatment was seasonal and followed a blueprint of specific treatments in autumn, winter and spring/early summer. However, liver fluke disease now represents a moving target so farmers are advised to monitor the fluke situation on their farms and, in consultation with their vet/animal health advisor devise specific fluke control strategies for their specific fluke situation. Finally, no single control strategy is likely to work on its own so farmers may need to consider an integrated approach including grazing management, drainage and flukicide treatment for best results.
Fig.1. Adult liver fluke (image © Sinclair Stammers)
Fig.2. Liver fluke life-cycle (image © Moredun Research Institute) 
Dr Philip Skuce is senior research scientist at Moredun Research Institute, just outside Edinburgh. Moredun runs a membership scheme which aims to keep farmers and their vets up to date with the latest developments in animal health research. If you would like a free copy of a twelve page factsheet on liver fluke control in sheep or are interested in becoming a member of Moredun, please contact Maggie Bennett at The Moredun Foundation, Pentlands Science Park, Bush Loan, Penicuik, EH26 0PZ phone 0131 445 5111 email
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or visit their website at www.moredun-foundation.org.uk
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