Status of HPAIv

Understanding the timing and distribution of virus spread is critical for global commercial and wildlife biosecurity management. The current global HPAIv panzootic poses a serious threat to animals and public health, having affected approximately 600 bird and mammal species globally and over 83 million birds across North America as of December 2023. Of particular concern is the transmission of the virus to mammals, including the recent discovery of infections in dairy cattle in the U.S. and the detection of HPAIv in milk, posing a significant human health concern.

While previous studies linked bird migrations to avian flu outbreaks at poultry farms, only one earlier study by USGS authors predicted the virus could spread to cattle. It found wild waterfowl moving between natural wetlands and cattle facilities, likely attracted to supplemental water and food sources when natural resources dwindled along the Pacific Flyway.

Predictive Models & Key Findings

The study combined extensive, long-term GPS tracking data from 16 species of wild waterfowl across North America with on-ground, county-level HPAIv surveillance data to understand the overlap of waterfowl and HPAIv detections. The researchers were also able to predict future outbreaks in counties and provincial areas through bird movements using a novel empirical SI (Susceptible-Infected) model, similar to the SIR (Susceptible-Infected-Recovered) model used to model COVID disease dynamics, via exposed migratory waterfowl.

The SI model projected exposure of up to 100% of birds via ‘outbreak’ exposure in counties with HPAIv occurrence during spring migration, except for Pacific flyway birds, which were predicted to experience widespread arrival of HPAIv via ‘birdbird’ exposure (up to 100%) during fall migration. The SI model accurately predicted HPAIv arrival in all flyways by migratory waterfowl, raptors, and ‘other’ birds but was a lagging indicator for commercial facilities, Pelicans, and resident waterfowl/captive species in the Pacific flyway.
 

This United States Geological Survey news article "RESEARCH SPOTLIGHT: Predicting the Spread of Highly Pathogenic Avian Influenza Virus Using Animal Movement Data" was originally found on https://www.usgs.gov/news