you know, i find it funny, the explanation of the Alteran shielding the milky way from the Ori's view.
because how did the Alteran get the plague in the milky way if the Ori didn't know where the milky way was?
i mean did one of the Ancients take a vacation stroll into the Ori galaxy at some point and get exposed to this virus and didn't know he or she had it and bring it back to the milky way?
that part was never really explained which is why i came up with this speculation explanation of how it could have possibly happened. but it's never told just how they got the disease in the first place.
In some cases it's outright automatically assumed it came from the Ori because it resembles some of the same traits of this disease within their history of the Ori, so how did they get the disease?