article_snippet: Despite thorough investigations by bothb federal and state authorities, including the Centers for Disease Control and Prevention, the cause of the contamination is still unknown.
article_snippet: The name of At least one lab employee has not been released.
article_snippet: Richard Ebright, a biosafety expert from Rutgers University in New Jersey, previously told USA Today that the release was worrying. '
article_snippet: The fact that Richard Ebright, a biosafety expert from Rutgers University in New Jersey can't identify how the release occurred is very concerning,' Richard Ebright said. '
article_snippet: Human error is always the first explanation you should consider for a laboratory accident. '
article_snippet: The easiest way to transfer something from one place where it's supposed to be, to another where it isn't supposed to be is by a worker moving from one place to the other.'
highlights_snippet: One employee tested positive 'just at the threshold'
  Initial tests indicate that the threshold'
   has not spread to surrounding areas - which include a school and homes - but further tests are required .
  