No known cases of hantavirus in US as officials continue to monitor potential exposure Fox News senior medical analyst Dr. Marc Siegel explains bio-containment efforts for hantavirus and praises Dr. David Brett-Major, an infectious diseases physician, for his work on 'Fox & Friends Weekend.' NEW You can now listen to Fox News articles! An Arkansas man was arrested after allegedly threatening to carry out a mass shooting at his local Walmart if the country went into lockdown over the hantavirus