Bird flu typically spreads among birds, but there have been recent outbreaks among cattle in the U.S., and one Texas man contracted the virus from sick cows. Here’s why so many experts are worried about a possible new pandemic.

A hospitalized patient in Missouri was infected with bird flu despite having had no known contact with dairy cows or other animals associated with an ongoing outbreak, health officials informed. This is the 14th person in the US sickened with H5N1 since March this year,