Category Archives: Disease Prevention
A new virus that has decimated tilapia populations in Ecuador and Israel has now been found in Egypt according to a new report from WorldFish in partnership with the University of Stirling, Scotland. Scientists are now trying to establish a firm link between the virus and a recent surge in mortalities in Egyptian farmed tilapia.
Tilapia Lake Virus (TiLV) is a global threat to the tilapia farming industry worth US$7.5bn per year.
In recent years fish farms in Egypt have seen increased mortality of farmed tilapia in the summer months, so-called “summer mortality”. Epidemiological surveys indicated that 37% of fish farms were affected in 2015 with an average mortality rate of 9.2% and an estimated economic impact of around US$100 million/year.
Identifying the cause of and preventing these fish deaths is of significant importance in Egypt, which relies on domestic aquaculture for 60% of fish consumed with tilapia making up 75% of that production. Tilapia is the cheapest form of animal protein in the country, so the findings have significant implications for the Egyptian people, particularly poorer consumers. The Egyptian aquaculture sector is the largest producer of farmed fish in Africa (1.17 million tonnes in 2015) and the third largest global producer of farmed tilapia after China and Indonesia.
Dr Michael Phillips, Director of Science and Aquaculture, WorldFish: “Tilapia were previously considered to have good disease resistance. While the report and the emergence of TiLV will likely not dent the species’ significance in global aquaculture it is a sign that greater efforts must be made to manage disease risks in tilapia farming. Research now needs to focus on finding solutions for this emerging challenge to the world’s tilapia farms.”
“Globally, there is no aquaculture system that is free from the risk of disease,” explains virologist Professor Manfred Weidmann from the University of Stirling. “Unless we are able to manage disease, minimize its impact, and bring down the prevalence and incidence of diseases we will not be able to meet future demand for fish.”
WorldFish scientists in collaboration with the University of Stirling will now work to establish whether TiLV is the primary cause of ‘summer mortality’ and, if that is the case, recommend rapid action to control the spread of the disease, including increased biosecurity in the short term. Longer-term strategies being studied by WorldFish and partners include vaccines and the genetics of disease resistance, that may open the way towards breeding of strains of tilapia that are resilient to TiLV.
Tilapia is an important species for aquaculture because it can be grown in diverse farming systems and is omnivorous, requiring minimal fishmeal in its feed. It has a naturally high tolerance to variable water quality and can grow in both freshwater and brackishwater environments. Tilapia are particularly important in developing world contexts where they are inexpensive and easy for small-scale farmers to grow for food, nutrition and income.
WorldFish is an international, nonprofit research organization that harnesses the potential of fisheries and aquaculture to reduce hunger and poverty. Globally, more than one billion poor people obtain most of their animal protein from fish and 800 million depend on fisheries and aquaculture for their livelihoods. WorldFish is a member of CGIAR, a global research partnership for a food-secure future.
CGIAR is a global research partnership for a food-secure future. Its science is carried out by the 15 research Centers that are members of the CGIAR Consortium in collaboration with hundreds of partners.
University of Stirling
The University of Stirling is ranked fifth in Scotland and 40th in the UK for research intensity in the 2014 Research Excellence Framework. Stirling is committed to providing education with a purpose and carrying out research which has a positive impact on communities across the globe – addressing real issues, providing solutions and helping to shape society.
An international scientific team led by researchers at Columbia University’s Mailman School of Public Health and Tel Aviv University has identified and characterized a novel virus behind massive die-offs of farmed tilapia in Israel and Ecuador, which threatens the $7.5 billion global tilapia industry. A paper in the journal mBio describes tilapia lake virus (TiLV) and provides information needed to fight the outbreak.
Known in its native Middle East as St. Peter’s fish and thought to be the biblical fish that fed multitudes, tilapia provides inexpensive dietary protein. The world’s second most farmed fish, tilapia is also the basis of aquaculture employment in developing countries in Asia, Latin America, and the Middle East. (The United States is the leading tilapia importer globally.) Since 2009, Israel has seen precipitous declines in tilapia, with annual yields plummeting as much as 85 percent–highly unusual considering the fish is known to be relatively resistant to viral infections. Similar die-offs have been seen in Ecuador and Colombia.
The scientists used high-throughput sequencing to determine the genetic code of the virus from tissue taken from diseased fish in Israel and Ecuador. This process would normally be sufficient to identify the culprit, but in this case, the resulting DNA sequences didn’t match any known virus, with the exception of a small genetic segment, that only remotely resembled a virus associated with the reproduction of influenza C.
Undeterred, the researchers employed other tools from their scientific tackle box, providing ample evidence that the genetic material was the same as the implicated virus dubbed TiLV. They used mass spectroscopy to characterize the proteins in cells growing the virus, which matched those they expected to see based on the genetic sequence. By analyzing the structure of viral DNA, they went on to observe 10 gene clusters with complementary endpoints, suggesting a circular form associated with a common type of viral reproduction involving a protein called a polymerase.
Finally and conclusively, healthy fish were exposed to TiLV cultured in a laboratory, resulting in disease that matched with what was seen in those countries: in Israel, the fish had swollen brains; in Ecuador, liver disease. In the coming weeks, the researchers will publish on the link between the TiLV and an outbreak of disease among tilapia in Colombia.
“The TiLV sequence has only minimal similarity in a small region of its genome to other viruses; thus, the methods we typically use to identify and characterize viruses through sequencing alone were insufficient,” says first author Eran Bacharach, a molecular virologist at Tel Aviv University.
“It appears to be most closely related to a family of influenza viruses called orthomyxoviruses; however, we still don’t understand much about its biology,” adds Nischay Mishra, associate research scientist at the Center for Infection and Immunity at Columbia’s Mailman School.
Importantly, the findings provide the genomic and protein sequences necessary for TiLV detection, containment, and vaccine development.
“We are shifting our focus now to implementing diagnostic tests for containment of infection and to developing vaccines to prevent disease,” says Avi Eldar of the Kimron Veterinary Institute in Bet Dagan, Israel.
The team of 18 researchers represent five institutions in four countries: the Center for Infection and Immunity and the New York Genome Center in the U.S., Tel Aviv University and Kimron Veterinary Institute in Israel; the University of Edinburgh, Scotland; and St. George’s University, Grenada, West Indies.
“The New York Genome Center was excited to join in characterizing this novel virus and contribute to this important environmental and globally impactful research,” says Toby Bloom, the Center’s deputy scientific director.
“Gumshoe epidemiology, molecular gymnastics and classical microbiological methods were required to link this new virus to disease,” says Ian Lipkin, senior author, director of the Center for Infection and Immunity and John Snow Professor of Epidemiology at the Mailman School. “Resolution of this mystery was only possible through the concerted efforts of this talented group of international collaborators.”
While best known for identifying viruses behind human disease, the Center for Infection and Immunity, pinpointed the virus beyond a disease that decimated salmon farms in Europe in 2010. They have done similar work with seals, sea lions, and Great Apes.
The current research was supported by grants from the United States-Israel Bi-National Agricultural Research & Development Fund (BARD IS-4583-13), the Israel Ministry of Agriculture & Rural Development Chief Scientist Office (847-0389-14), U.S. National Institutes for Health (AI109761), USAID PREDICT, and a fellowship to J.E.K.T. from the Manna Center Program in Food Safety and Security at Tel Aviv University. The authors declare no conflicts.
Aquaculture Symposium taking place on 24 of March all day at Meeting Room 2 (3rd floor) of SECC in Ho Chi Minh City Vietnam which focus on Infectious diseases of Tilapia & Strip catfish invite 4 Fisheries experts from Veterinary Pathobiology, Faculty of Veterinary Science, Chulalongkorn University Bangkok, Thailand and the specialist in Tilapia from Vietnam to join the session.
The interesting topics are Franciscellosis, Streptococcosis, Columnaris disease in Tilapia and Strip catfish and Concurrent infection & Miscellaneous diseases, Antibiotic resistance in Aquaculture, Vaccine for Tilapia and Strip catfish and close session with Viral Nervous necrosis in Tilapia. This class is special for fish farmer to understand and study how to solve the infectious diseases of Tilapia and strip catfish in Vietnam. FAVA believe that this class will create the valuable knowledge for all delegate and the 120 seats are limited.
All conference program, please visit here
For more information of ILDEX Vietnam 2016, please visit www.ILDEX-VIETNAM.com
Topics Include Disease Trends in Asia, Sustainable Production and Health Management
MADISON, NEW JERSEY, March 26, 2015 – Merck Animal Health (known as MSD Animal Health outside the United States and Canada) today announced a High Quality Tilapia Meeting to be held on April 4 during the Tilapia 2015 Congress, the 4th International Trade and Technical Conference and Exposition on Tilapia. Merck Animal Health is a Platinum Sponsor of the Congress, which will take place at the Palace of the Golden Horses hotel in Kuala Lumpur, Malaysia from April 2-4.
“As demand for fish protein continues to rise, fish farmers need solutions that can help them ensure consistent and sustainable harvests,” said Norman Lim, Regional Technical Manager for Aquaculture in Asia. “Merck Animal Health has pioneered the development of tilapia vaccines in Asia, and we are pleased to expand our support through the High Quality Tilapia Meeting, to help fish farmers increase their productivity by taking an integrated approach to health management.”
The High Quality Tilapia Meeting will feature sessions led by industry experts and Merck Animal Health representatives on a variety of topics related to tilapia production, including disease trends in Asia, the role of diagnostics and genetics, and the benefits of an integrated approach to health management. Sessions and speakers include:
- Session Introduction – Chris Haacke, Merck Animal Health
- Tilapia Disease Trends in Asia – Dr. Chang Siow Foong, Merck Animal Health, R&D Site Lead, Singapore
- The Importance of Diagnostics in the Health Management Process – Dr. Diana Chee, Aquatic Veterinarian, Agri-Food and Veterinary Authority, Singapore
- The Role of Genetics in Animal Health and its Contribution to Sustainable Production – Dr. Jim McKay, Group Director, Science and Technology, Aviagen UK (EW Group)
- Quality Healthy Fingerlings – Dr. Prakan Chiarahkhongman , CPF (Thailand)
- Nutrition and Health Management – Dr. Minh Anh Pham, Aqua R&D Manager, InVivo NSA
- Integrated Approach to Tilapia Health Management – Norman Lim, Merck Animal Health
- Certification and Implications for Health Management – Michiel Fransen, Standards and Certification Coordinator, Aquaculture Stewardship Council
The introduction of vaccination in aquaculture has led to high levels of sustainability, productivity and improved performance in many major fish farming industries around the world. This approach to disease prevention has also allowed for investment in more efficient production methods and better feed utilization and formulations, driving sustainable production growth.
For more information about the High Quality Tilapia meeting, visit: http://highqualitycongress.com/# . To register for the Tilapia 2015 Congress, visit http://infofish.org/tilapia2015/index.php/programme .
Supporting Aquaculture in Asia and Beyond
In January 2000, Merck Animal Health opened a Research and Development Center in Singapore to develop high-quality aquaculture animal health products and application strategies for warm water fish-farming in the Asia-Pacific region and beyond. In July 2012, Merck Animal Health obtained approval from Indonesian authorities to market the first vaccine for tilapia, AQUAVAC® Strep Sa for managing streptococcosis, a prevalent bacterial disease that can cause high levels of mortality and sharp decreases in fish performance. The availability of the tilapia vaccine continues to expand through product registrations in key tilapia-producing regions around the world. The company also runs a comprehensive technical and educational program known as ‘Strep Control Your Tilapia Health’ to support the implementation of vaccination programs and integrated health management on tilapia farms.
For more information about Merck Animal Health’s aquaculture business, visit http://aqua.merck-animal-health.com .
A series of high quality aquaculture training videos, designed to teach Egyptian fish farmers the industry’s best management practices, has recently been released.
Produced by WorldFish, an international nonprofit research organization, the ten short videos are being used to train local fish farmers in the most effective ways to boost the production and quality of farmed fish.
Available in Arabic with English subtitles, the videos cover all aspects of aquaculture from pond preparation and fish health care, to how to transport and handle live fish.
“These videos are good learning tool for fish farmers to show them the industry’s best management practices in a simplified way”, says Dr. Diaa Al-Kenawy, Research Scientist at WorldFish.
“Both the trainers and the farmers found the videos very useful because they explain all fish farming stages from site selection and pond design to harvest and post-harvest treatment”, he adds.
The videos are part of the Improving Employment and Income through the Development of Egypt’s Aquaculture Sector (IEIDEAS) project, which aims to strengthen and develop the country’s US$1.5 billion aquaculture industry and generate more employment in the sector.
The IEIDEAS project is part of the CGIAR Research Program on Livestock and Fish, which aims to increase the productivity of small-scale livestock and fish systems in sustainable ways, making meat, milk and fish more available and affordable to poor consumers across the developing world.
Strengthening the aquaculture industry in Egypt will help to secure the livelihoods of over 100,000 men and women employed in the sector, and ensure an affordable source of animal protein for the millions of poor who depend on fish.
While the videos are targeted at Egyptian fish farmers, they offer industry tips that will benefit pond-based aquaculture producers around the world.
Watch the videos. http://www.youtube.com/playlist?list=PL_5s5CPGqCKQtv15flpx4UKDltm3JyEIM
WorldFish, a member of the CGIAR Consortium, is an international, nonprofit research organization committed to reducing poverty and hunger through fisheries and aquaculture.
CGIAR is a global agriculture research partnership for a food secure future. Its science is carried out by the 15 research centers who are members of the CGIAR Consortium in collaboration with hundreds of partner organizations.
For more information or to request an interview please contact:
Diane Shohet, Director, Communications and Marketing, WorldFish
Tel: +6017 474 8606