Migration routes hold key to bird flu spread, global study finds
Monitoring the migration routes of wild birds could help to provide early warning of potential bird flu outbreaks, experts say. The recommendation follows new research, done by an international research team including Utrecht University, that shows migrating birds can help to spread deadly strains of avian flu around the world.
This study would not have been possible without the input from different people with different expertises, including epidemiologists, molecular virologists, veterinarians and bird experts."
Some strains of bird flu viruses are highly lethal in poultry they infect and pose a major threat to poultry farms worldwide. In rare cases, the viruses can also infect people and cause life-threatening illness. Researchers investigated how a subtype of bird flu called H5N8 spread around the world following outbreaks in South Korea that began in January 2014. The virus spread to Japan, North America and Europe, causing outbreaks in birds there between autumn 2014 and spring 2015.
Migration patterns of wild birds need to be analysedScientists analysed migration patterns of wild birds that were found to be infected with the H5N8 virus. The team then compared the genetic codes of viruses isolated from infected birds collected from 16 different countries. Their findings reveal that H5N8 was most likely carried by long-distance flights of infected migrating wild birds from Asia to Europe and North America via their breeding grounds in the Arctic. The researchers say their findings reinforce the importance of maintaining strict exclusion areas around poultry farms to keep wild birds out.
Greater surveillance of wild birds at known breeding areas could help to provide early warning of threats of specific flu virus strains to poultry and people, they add. Deadly bird flu strains – known as Highly Pathogenic Avian Influenza (HPAI) – can kill up to 100 per cent of the poultry they infect within a few days.
Study: worldwide scientific cooperation The study was conducted by the Global Consortium for H5N8 and Related Influenza Viruses and involved scientists from 32 institutions worldwide. In the Netherlands, these were Erasmus MC, University of Utrecht, and the Central Veterinary Institute.
Senior author Professor Thijs Kuiken, of the Department of Viroscience, Erasmus MC, Rotterdam, said: "Bird flu is a global problem and its solution requires global collaboration among researchers. We see this study as a model for how scientists worldwide should work together to fight emerging infectious diseases. Important roles of Erasmus MC in this study were to mobilize its worldwide network of scientists and to bring together the disciplines of epidemiology, ornithology, and phylogenetic analysis."
Professor Marion Koopmans, also of the Department of Viroscience, said: "This study illustrates that global collaboration, data sharing and joint thinking can help to understand global spread of diseases that threaten livestock and humans. It also shows how connected the globe is and that we need to invest in these collaborations to be prepared for the emergence of novel diseases with capability for global spread."
Joint first authors were Dr Rogier Bodewes, of the Faculty of Veterinary Medicine, University of Utrecht, and Dr Samantha Lycett, of the University of Edinburgh’s Roslin Institute. Dr Bodewes commented: "This study would not have been possible without the input from different people with different expertises, including epidemiologists, molecular virologists, veterinarians and bird experts."
Dr Lycett said: “Bird flu is a major threat to the health and wellbeing of farmed chickens worldwide. Our findings show that with good surveillance, rapid data sharing and collaboration, we can track how infections spread across continents.”
Professor Mark Woolhouse, also of the University of Edinburgh, said: “This study could only have happened through bird flu researchers around the world pooling resources and working together. We see this as a model for how scientists should unite to combat infectious diseases of all kinds.”
Ruth Bouwstra, previously of the Central Veterinary Institute, currently at GD Animal Health, stated: "It is important for the poultry industry to take this new route of spread for highly pathogenic avian influenza."
The study is published today in the journal Science and was partly funded by the COMPARE project, an EU-funded multidisciplinary research network that is developing a globally linked data and information sharing platform for the rapid identification and tracking of emerging infectious diseases and foodborne outbreaks.
This research is closely related to Utrecht University’s strategic research theme Life Sciences, under the subtheme Public Health.