The cause of the E. coli outbreak in Germany remains a mystery.  The outbreak is the deadliest in modern history with at least two-dozens deaths and more than 2,400 people sickened.  Eleven other European nations and the United States also report E. coli cases and say most of the victims had visited Germany.  But some health officials in the United States say it may be just a matter of time before a similar E.coli outbreak happens in the United States.  VOA’s Chris Simkins has more on the story.