US scientists turn to chickens to sound the alarm as West Nile cases rise

Key Points:

• West Nile virus transmission began unusually early in some US states this year, with the highest early summer cases since 2004, prompting Delaware to use sentinel chickens as an early warning system for mosquito-borne diseases like West Nile and Eastern equine encephalitis (EEE).
• Sentinel chickens, kept in flocks across Delaware since the 1980s, serve as "dead-end hosts" that can test positive for viruses without spreading them, allowing officials to pinpoint virus activity locations and better target mosquito control and public warnings.
• Although some states use mosquito pool testing for faster virus detection, Delaware prefers chickens because they provide more precise location data, as chickens do not move from their designated areas unlike mosquitoes.
• Decades of data from sentinel chickens help researchers create predictive models linking environmental factors such as temperature, precipitation, and landscape with virus activity, improving understanding of the conditions driving outbreaks.
• While exploring new methods like honey traps, Delaware continues to rely on sentinel chickens due to their proven effectiveness and reliability in monitoring mosquito-borne diseases and aiding public health responses.