Blood tests confirm a second person in Missouri caught bird flu without exposure to infected animal, but questions remain

​ Blood tests of several people who were in contact with a patient in Missouri who caught H5N1 bird flu without any known exposure to infected animals reveal at least one of them — a person who lived in the same house and had symptoms at the same time — also had the virus, according to two sources with knowledge of the investigation. Read More Breaking News, Latest News and Videos | CNN