Background Articles

As bird flu cases go underreported, health officials risk being slow to notice if the virus were to become more contagious. A large surge of infections outside of farmworker communities would trigger the government’s flu surveillance system, but by then it might be too late to contain.

In recent weeks, three human infections with the virus have been confirmed—all in dairy workers who had contact with sick cows. All three developed symptoms of eye infections known as conjunctivitis. The latest case, reported in Michigan this week, also involved respiratory symptoms more typical of a flu infection.

This article examines the unique spread of bird flu across multiple animal species, marking an unusual animal pandemic.