This is good, but it has some issues. It's the regular body-snatcher affair, and most of it is only biding its time for the ending (a tactic I'm admittedly well-acquainted with myself). The containment protocols are great; my first impression was "that seems a little extreme", but it's justified by the anomaly.
This is where it gets sloppy, though. The effects are scatterbrained. Does it really matter that it eats without a mouth? Is that supposed to scare me? Or that it burrows into something without creating a hole, somehow? I'm sorry to say, this part made me think the author was winging it. Similarly, RPC-430-B is insignificant, and the image of a sea cucumber with human legs is laughable.
RPC-945 is the best human parasite RPC I've read because it nails its purpose. It has multiple effects, but each one has a reason to happen. While its description is light in explanatory detail, it gets away with this because each part is described in the same amount of detail so that none of them feel lacking. This article has long paragraphs of confusion. Thoughtlessly expanding an idea can make it less scary.
The interview log is the real point of the article, and it has that strong writing that I've been asking for. It may be the best implementation of this trope on the whole wiki. I'm impressed to see blackboxed names actually working for once, making the characters more faceless and all-encompassing. It could happen to YOU! My only complaint is that the researcher calling it "A2" is silly and detracts from the mood.
I was left in a good mood, so I'll give this a 4/5.