Pretty much worldwide, since there's usually only a few manufacturers of the Active Pharma Ingredients supplying the whole market.
Scale matters.
In this case, the manufacturer came up with a new technique for manufacturing the API. They failed to account for these very small molecule impurity side-products in their model/testing.
They probably filtered out a lot of it in their purification process and still met USP standards, but 99% or 99.9% pure still leaves a risk for potent side products.
Sometimes these side-products are tested for, but you have to know what to look for. A tiny blip may not be elucidated.
Scale matters.
In this case, the manufacturer came up with a new technique for manufacturing the API. They failed to account for these very small molecule impurity side-products in their model/testing.
They probably filtered out a lot of it in their purification process and still met USP standards, but 99% or 99.9% pure still leaves a risk for potent side products.
Sometimes these side-products are tested for, but you have to know what to look for. A tiny blip may not be elucidated.