Does reducing the Purple Worm’s HP to 184 really reduce its challenge rating to 13?

On page 113 of Princes of the Apocalypse the text reads in part:

As the tremor ends, a young purple worm with 184 hit points (challenge rating 13) burrows…

No other changes to the Purple Worm’s stats are given and the monster does not appear in the Monsters section at the end of the book. This monster also shows up on DnD Beyond’s encounter builder as a CR 13 monster as "Young Purple Worm", in contrast to the CR 15 "Purple Worm".

Is taking away 63 hit points with no other changes to this monster enough to drop it two challenge ratings? I’d like to challenge, but not kill, my party.

What’s the name of the AD&D module with the parasitic worms in the rubble?

I’m trying to remember a module, AD&D I’m fairly certain. They had a listing of rooms and what was there. A few of the rooms had rubble in them which could be searched for treasure with one of them instead hiding a cache of parasitic worms in the rubble which would attack any searching PCs (presumably to discourage Always Check Behind The Chair) with the mild twist that, after the worms were defeated, a second search found some valuable treasure (jewelry, I think). Anyone familiar with this module?

After looking at the listed answers, it sparked a bit of memory. The rooms being listed were along a corridor. It’s the weirdest thing, but my memory is that it’s a rough rock corridor, but it was houses on either side that were available to search. That suggests to me it was either a canyon or somewhere underground. They were dilapidated, but I am not certain if it was due to simple disrepair or if it was due to an earthquake.

While trying to trace down a vague memory of Boggles, I found the Secret of the Slaver Stockade module, but it does not seem to quite match up. There is a bit of rubble with vipers, but no double bluff with the second search finding treasure. That and it just doesn’t have that same feeling as the memory of something wormlike burrowing into the questing adventurers.

Would Spawn of Kyuss worms infesting a Paladin die?

At third level, Paladins gain the feature Divine Health:

By 3rd level, the divine magic flowing through you makes you immune to disease. (PHB, p. 85)

There’s a monster in Volo’s Guide To Monsters called the Spawn of Kyuss which can infect enemies with a burrowing worm. If it burrows into a creature, the worm will deal necrotic damage to its target at the end of the target’s turn. But there is a way to remove or neutralize the worm:

If a worm-infested creature is targeted by an effect that cures disease or removes a curse, all the worms infesting it wither away. (Volo’s Guide, p. 192, bold added)

My question is whether the Paladin’s “Divine Health” counts as being “targeted by an effect that cures disease”. It certainly is an effect, and it could be seen to cure disease, but I’m not sure if an “always on” effect can be said to have “targeted” someone (my inclination is to say it can’t). So would the Paladin’s Divine Health kill the worm as soon as it burrowed in? Or would the Paladin need some other method (like his/her “Lay On Hands” ability) to remove this infestation?