As of Friday, all that was known about the Missouri case was that the individual was infected with an H5 virus. The CDC was still working to try to figure out the neuraminidase of the virus, the N of its name. Sometimes that isn’t possible, for instance if there isn’t a lot of virus in the sample from the patient.

A case of bird flu has been confirmed in a Missouri resident who had no known contact with dairy cows, poultry or wild birds, U.S. health officials report. "The patient, who was hospitalized, had underlying medical conditions,