(My apologies if this has been already asked. I searched through past posts and did not find this covered.)
----------------------
There is no "Detect Disease" spell, as far as I can tell, so . . .
Hypothetical Situation #1: Say there is a virulent disease stalking the land, and it's transmitted via fluids (drinking water, rivers/streams/swamps, cave mold/slime, bodily fluids like blood/sweat/saliva, etc).
Will Detect Poison detect the presence of pathogens in fluids?
If yes, please clarify another point:
In the case of a swamp or tainted drinking water, there may be many different pathogens in the liquid. Can a spellcaster differentiate between the relatively benign pathogens that cause simple diarrhea vs deadly pathogens that cause horrible death? Or does the spell simply tell the caster that the liquid is "infected with something".
After all, in a fantasy setting it might be safe to assume that virtually every jug of water one is presented contains SOME sort of pathogen.
Hypothetical Situation #2: Say that the disease can be transmitted through the air and/or on dry surfaces. Will Detect Poison detect the presence of the pathogen in these instances? Does the spell simply tell the caster that a nearby 5ft cube of air is "infected with something", or will the spellcaster be able to tell the difference between common allergens/pathogens vs something really nasty?
Hypothetical Situation #3: Now, let's say that the disease in question is actually Zombie Rot Disease.
Will Detect Poison detect the presence of Zombie Rot Disease in a character or NPC who has been infected but has not yet succumbed to its effects?
If Detect Poison can't do it, would Detect Undead or Detect Magic detect the presence of Zombie Rot Disease?
Finally, can Zombie Rot Disease be transmitted via fluids that are left behind by a plague zombie or by an infected person who has not yet died?
In other words, is Zombie Rot Disease a "traditional" pathogen (detectable perhaps by Detect Poison)?
If not, is it a "magical" disease (detectable by Detect Magic) or is it transmitted by bacteria or viruses that are actually undead organisms in and of themselves (and therefore detectable by Detect Undead)?
THANKS IN ADVANCE!
FYI: Our DM allows us to diagnose diseases in characters or NPCs by making a successful Heal check.
But in many cases one would rather not have to get close enough to the subject to use the Heal skill, lest the characted contract the disease themselves. Detecting a disease from a semi-safe distance would be a much preferable option.
Also, in many cases the Heal skill is not practical because the subject might not allow themselves to be examined, due to delirium or if it's a hostile NPC, for example.
The Heal skill also wouldn't help when trying to detect the presence of disease in a body of water, or a slime-coated cave, or some other inanimate object.
Our DM says that Detect Poison only detects chemical poisons, not pathogens (and especially not an exotic disease like Zombie Rot Disease).
After all, the rules specifically say that the spell allows the caster to "determine whether a creature, object, or area has been poisoned or is poisonous". It does not say that the caster is able to "determine whether a creature, object, or area has been poisoned, is poisonous, or is infected with disease."
It seems illogical that ancient wizards and clerics would create spells for detecting poison, undead, evil, good, etc, but would not create a spell for detecting disease.
I'm just sayin'...
FINAL QUESTION: If a character or NPC has died from being poisoned, will Detect Poison determine the cause of death?
In the real world, the length of time a poison remains in the body depends on which poison is used.
In the game world, should we assume that the poison lingers indefinitely or should we assume that the poison disappears immediately upon death?
Similarly, if a character or NPC has died from contracting a pathogen (whether traditional, magical, or undead), would the corresponding "detect" spell determine the cause of death?