Egg production in the U.S. dropped 4% in November as the price of eggs and cases of bird flu continue to rise across the country.

The virus is spreading among animals, while viral mutations raise concerns about potential adaptation to human hosts.

The Centers for Disease Control and Prevention is keeping close eye on pandemic indicators amid bird flu cases arising in the United States.

The CDC has revealed the red flags it is monitoring for that suggest that bird flu was about to become the world's next pandemic.