I believe this bug hasn’t been posted yet, or at least I couldn’t find it in this forum. I apologise beforehand for not attaching the files because I’m not currently using the machine the game is installed on.
Anyway, the bug:
It appears that the ‘sick’ condition of a Brother reduces his current (at the moment of save) hp each time a game is loaded to that save (to a minimum of 1); in several ‘consecutive’ saves this results in health dropping all the way down to 1. This is aside the penalty to max hp, but it appears to decrease the hp either by about the same amount (15; possibly slightly more or less): in one case it went from modified full hp of ~45 to 20, in another it went from ~20 to 11, and then in several cases of hp between 1 and somewhere in ‘teens (~16-17) it went down to 1 (in case of 1 it always stays at 1).
I noticed this after I tried loading saves made several in-game hours apart (i.e. less than enough to pass the barrier of ~18 hp) and clearly remembered the hp status at the time of the save. Before that I assumed it was a matter of ‘fever taking him’, per the description text of the condition.
Reproducibility: Always, but on N=1 (haven’t had any other brother in any company get sick so I could test).
No signs of the game behaving improperly, no other bugs encountered, no errors. Might be a secret feature, but somehow I doubt it.