In its current form, the H5N1 bird flu virus lacks essential properties that would allow it to spread easily among humans. But in the rare cases when it does infect a person, the virus is frequently lethal. Despite an alarming case recently in which six members of a family in Indonesia died from H5N1, scientists have not found evidence that the virus has mutated into a more transmissible form. Meanwhile, virologists are gaining a better understanding of what makes H5N1 so deadly to humans.
By Seth Hamblin And Cristina Rivero, The Washington Post - July 3, 2006