Climate change suggests a shift of H5N1 risk in migratory birds

Migratory birds are considered to have played an important role in the spread of highly pathogenic avian influenza H5N1. However, how bird species are expected to modify their wintering sites in response to climate change, and in turn affect the geographic distribution of the risk associated with H5N1 outbreaks, is unknown. We explored the association between past climate variability and H5N1 outbreaks that were attributed to migratory birds from 2005 to 2009. We then predicted the distribution of risk associated with H5N1 outbreaks based on future climate change scenarios. Overlapping the probabilities of bird distribution and H5N1 outbreaks produced final emergence risk. Our results suggest that minimum daily temperature in the winter (−15 to –11°C, 15 to 17°C) and maximum daily temperature in the summer (12 to 15°C, 30 to 35°C) governed wild bird migratory routes, while high mean air pressure and low mean specific humidity in the winter impacted the outbreaks of H5N1 among migratory birds. By the end of 2030, Europe may be at higher risk for H5N1 outbreaks in January and February. Northern Africa and Southern and Western Asia will likely be a higher risk for H5N1 outbreaks from April to June. Our findings suggest a potential shift in H5N1 risk from Southeast Asia to the western part of the world due to climate change. The results of this study could be used to inform policy in the area of H5N1 outbreak detection and preparedness.