Bird flu cases are rising rapidly in the United States and around the world. A new study traces how the disease spread over the last two decades from Asia to Europe, Africa and the Americas. New bird species, from pelicans to peregrine falcons, are catching and carrying the disease, the study finds. The pattern may be a clue to why culling domestic birds has not halted the most recent outbreak.
The study shows the important role a wider range of wild birds have as both victims and vectors of disease spread, upending previous assumptions about which birds spread the virus. The findings point to a need to revise how we monitor and treat avian influenza in birds, wild and domestic, to best protect human health.
Today, the biggest hotspots of avian influenza are in Europe and the Americas, rather than southeast Asia as it was in the 1990s, the study finds. But it’s not only the location that’s different; the disease’s temporal pattern is different, too.
“We know H5N1 has the potential to become a human pandemic, and the risk of that happening is higher than ever before,” said Raina MacIntyre, an epidemiologist at the University of New South Wales and study coauthor. She’s studied influenza for more than thirty years. “We need to really understand how it’s spreading, the role of newly infected species, and what that means in terms of risks. That gives us a better chance to mitigate those risks.”
“Using geospatial analysis techniques is key to understanding global changes in avian influenza” said Samsung Lim, a geographic information system expert at the University of New South Wales and study coauthor. “We combined GIS with epidemiology to better characterize how and why H5N1 has escalated in such an unprecedented way.”
The study was published in GeoHealth, which investigates the intersection of human and planetary health for a sustainable future.
