jamie created a dupe on genosha who tried to/did provide medical aid [via mouth to mouth] to a mutant/ate with the legacy virus. apparently madrox prime kept himself clear of said dupe after that incident, and the dupe who continued on in x-factor [with the legacy virus] died. haven tried to save him, but failed, and claimed the legacy virus was some fated, unstoppable curse made to plague mutantkind. the real jamie popped up later. or maybe it was the dupe who stayed separate and the real madrox died. i'm not sure if it was cleared up.
this series, besides having art i can't stand, has been relatively fantastic. i'm waiting for this "origin of layla miller" line to play out, see how she is connected to the decimation and singularity. it's captured my interest, to say the least.