A third dairy worker in this U.S. has contracted bird flu from a previously infected herd. This is the second dairy in Michigan with a confirmed case of dairy cow-to-human transmission. What differentiates this case is the worker reported upper respiratory tract symptoms. Acute respiratory illness is a typical symptom associated with influenza virus infection, including A(H5N1) viruses, according to the Centers for Disease Control and Prevention (CDC).

The worker was treated and the symptoms are resolving. Household contacts of the worker have not developed symptoms. They are being monitored according to the CDC. No additional farm workers reported symptoms and they are being monitored as well. Currently, there are no confirmed cases of person-to-person spread of the bird flu virus.

The CDC is closely monitoring influenza data from affected states. So far, there has been no sign of unusual activity.

Read more on the latest dairy farm worker diagnosed with bird flu here.