Why the New Human Case of Bird Flu Is So Alarming

The third human case of H5N1, reported on Thursday in a farmworker in Michigan who was experiencing respiratory symptoms, tells us that the current bird flu situation is at a dangerous inflection point.

The virus is adapting in predictable ways that increase its risk to humans, reflecting our failure to contain it early on. The solutions to this brewing crisis — such as comprehensive testing — have been there all along, and they’re becoming only more important. If we keep ignoring the warning signs we have only ourselves to blame.

H5N1 has long been more than a bird problem. The virus has found its way into dairy cattle across nine states, affecting 69 herds that we know about. Of the three human cases of H5N1 that have been identified, all involve farmworkers who were in direct contact with infected cows or milk. The first two cases were relatively mild, involving symptoms like eye irritation, or conjunctivitis. However, the most recent case has shown more concerning signs, including coughing.

The emergence of respiratory symptoms is disconcerting because it indicates a potential shift in how the virus affects humans. Coughing can spread viruses more easily than eye irritation can.

New symptoms should be expected as the virus continues to spread and adapt to humans. Yet our response to this looming danger has been woefully inadequate, particularly in the area of testing.

Testing is our first line of defense in identifying and controlling infectious diseases. It allows health responders to understand the extent of an outbreak, identify who is infected and take measures to prevent further spread.