The source of the infection is still not known.
Sequencing is still ongoing, but the hemagglutinin of the virus is related to the virus that is circulating in dairy cows. There haven't been any confirmed outbreaks in dairy cows in Missouri though.
The neuraminidase remains unknown at this time. There was limited RNA viral material in the patient. So the ultimate source is still a mystery.
The CDC is expanding their interviewing scope to hopefully pinpoint a source.
Fortunately Missouri hasn't seen further infections. We are beyond the infection window. So this may be a one off infection.
The CDC reaffirmed that the risk to the public remains low. Human infections have been rare and generally have had a known infected animal exposure (the Missouri case was the first US case without a known contact).