This is the first time in the US outbreak a person with H5N1 has displayed respiratory symptoms, unlike the previous two cases with only conjunctivitis, commonly known as “pink eye.”

The respiratory symptoms are concerning because they “increase the odds of exposing someone to the virus as compared to conjunctival symptoms”, Dr Nirav Shah, principal deputy director of the CDC told reporters on Thursday. “Someone who’s coughing may be more likely to transmit the virus than someone who has an eye infection like conjunctivitis.”

But no close contacts, including other workers on the farm, have reported symptoms so far, he said.

Great. Respiratory illness. That makes it so much more likely to be able to spread from an infected person.