The second case of a person contracting bird flu or H5N1 virus despite not being exposed to poultry or dairy cows has been reported, US health officials said. According to reports, this person had shared a home with a patient who was first hospitalized with bird flu in August.

Centers for Disease Control and Prevention officials told reporters Thursday that there is no evidence that there has been any case of human-to-human spread of H5N1 bird flu in the mysterious situation reported last month in which several people in Missouri suffered illnesses unrelated to known animal contact.

New test results suggest Missouri did not see a cluster of bird flu cases, a possibility that some experts had feared.