It is not clear why, but researchers at the Erasmus University Medical Center in the Netherlands and the University of Wisconsin-Madison have managed to modify the highly deadly H5-N1 (bird) flu so that it is easily spread from person-to-person.

Not surprisingly, security officials are very worried that the deadly flu could be released by terrorists.

Unfortunately, scientists found that it was easier than they had thought to modify the flu so that it was more contagious. The H5N1 flu is the `original` bird flu. It is very deadly with about 60% of those who are known to have contracted it, Die.

It is different from the H1N1 (swine) flu that spread widely in 2009. That flu was more deadly than normal seasonal flu, but nothing compared to the 1918 flu outbreak that killed millions of people world-wide.

That is bad news both from a security standpoint but also in terms of the possibility that strains could naturally mutate in that way.

On the plus side, having the mutated virus ahead of time might make it possible to develop vaccines. Of course releasing it for vaccine development also creates the possibility that it could be obtained by terrorists.

The U.S. National Institutes of Health funded the research.