New versions of the H5N1 virus are increasingly adept at spreading. Suggestions to either let it rip in poultry or vaccinate the birds could backfire.

Although the avian flu (H5N1) virus may not be making the news as frequently, it is still working hard behind the scenes, ...

Jeffery DelViscio/ Scientific American Science Quickly How Bird Flu Went from an Isolated Avian Illness to a Human Pandemic Threat (Part 1) ...

For months, bird flu was seemingly everywhere in the U.S.: news headlines reported the highly pathogenic H5N1 avian influenza ...

The H5N1 avian flu is circulating in cows and other mammals. Whether it will make a permanent leap to humans is another ...

Farm workers facing possible arrest would likely resist getting tested for bird flu should there be a resurgence this fall, ...

Several local factors—including the minimum temperature reached in autumn, the water level in lakes and ponds in winter, and ...

Extreme heat is impacting states across the country. See maps of high temperature forecasts and heat index levels.

Multiple U.S. states and Canadian provinces are experiencing poor air quality from wildfire smoke. Here's where.