Research Spotlight: Using Animal Movement Data to Predict the Spread of Highly Pathogenic Avian Influenza Viruses

HPAIv Status

Understanding the timing and distribution of virus transmission is critical for global commercial and wildlife biosecurity management. The current global pandemic of highly pathogenic avian influenza viruses poses a serious threat to animal and public health, affecting approximately 600 bird and mammal species worldwide and more than 83 million birds in North America as of December 2023. Of particular concern is the spread of viruses to mammals, including recent infections of dairy cows in the United States and detection of highly pathogenic avian influenza viruses in milk, posing a major threat to human health.

While previous studies have linked bird migration to avian influenza outbreaks on poultry farms, only an earlier study by the U.S. Geological Survey authors predicted that the virus could spread to cattle. That study found that when natural resources along the Pacific Flyway are depleted, wild waterfowl may be attracted to supplemental water and food sources, migrating between natural wetlands and cattle farms.

Predictive model and key findings

The study combined long-term GPS tracking data from 16 wild waterfowl species in North America with county-level ground-based HPAIv surveillance data to understand the overlap of waterfowl and HPAIv detections. The researchers were also able to predict future outbreaks at the county and provincial levels from bird activity using a new empirical SI (Susceptible-Infectious) model, similar to the SIR (Susceptible-Infectious-Recovered) model used to simulate COVID disease dynamics with exposed migratory waterfowl.

The SI model predicted that up to 100% of birds in HPAIv-infected counties would become infected with HPAIv through “outbreak” contacts during spring migration, with the exception of birds in the Pacific Flyway, which were predicted to become infected with HPAIv through “bird-to-bird” contacts (up to 100%) during fall migration. The SI model accurately predicted HPAIv infection in migratory waterfowl, raptors, and “other” birds on all flyways, but was a lagging indicator for commercial facilities, pelicans, and resident/captive species on the Pacific Flyway.