[timoth]

I'm a complete layman in this field, but the logical conflict between these two sections concerned me:

> she stabbed her left thumb with a curved forceps while cleaning a cryostat — a machine that can cut tissues at very low temperatures — that she used to slice brain sections from transgenic mice infected with a sheep-adapted form of BSE

Then later:

> Aguzzi declined to comment on the French CJD cases, but told Science his lab never handles human or bovine prions for research purposes, only for diagnostics. "We conduct research only on mouse-adapted sheep prions, which have never been shown to be infectious to humans," Aguzzi says.

Am I missing something, or is the logical conclusion that Aguzzi thinks his lab is avoiding disaster by only using mouse-adapted sheep prions, but the lady is suspected to have been infected by an injury related to "transgenic mice infected with a sheep-adapted form of BSE". I hope there's some nuance here, because otherwise it sounds like Aguzzi's lab isn't actually avoiding infection. Perhaps the lady's case isn't considered to have definitely confirmed infectiousness due to uncertainty (though no uncertainty seemed to be mentioned)? Or the mouse-adapted sheep prions Aguzzi's lab uses are different to the transgenic mice infected with a sheep-adapted form of BSE? I have no idea; it's just that the apparent conflict between these two sections jumped out to my layman's eyes.

[MathCodeLove]

I don't think there's any logical conflict. They stated that they thought the type of prion they were handling couldn't infect humans. They see now they were likely wrong.

[timoth]

I don't read any implication that they see they were likely wrong. According to the article, he actually refused to comment on the French cases and said their own lab "only use mouse-adapted sheep prions, which have never been shown to be infectious to humans." Not even "_had_ never been shown". It seems unclear what his view is.

It immediately goes on to talk about their own discovery 10 years ago that prions could be spread through aerosols which "totally shocked" them and might "warrant re-thinking on prion biosafety guidelines" but that seems an entirely separate thing from the decision to use only sheep prions for research.