Just stumbled across this interesting article:
Anyone familiar with this brand of sorcery? Other sources I’ve read seem to indicate that the perpetrators of this cannibalistic type of magic are possessed by a spirit called the Kanaima who is responsible for this pretty epic bloodlust. I wonder what, if anything, is granted in return for the murder and desecration of someone’s body like this. 
Welp, just added this book to my rapidly growing reading list. Interesting stuff to say the least… 
But why…what do they gain from the drinking of the rot juice? And how are they not affected by the bacteria?
Good questions. My guess is that there’s some spiritual substance they’re imbibing along with the physical rot juices… perhaps the essence or “soul” of the victim? Seems like a very predatory type of spirituality; eat or be eaten and all that jazz.
Well as a non-Kanaima myself, the only thing I can really say about it comes from having read that book in the past, but keep in mind that the writer was also a non-kanaima and therefore can’t be 100% completely and truly accurate.
Kanaima, aside from their traditional roles as revenge shamans, are predator-shamans, they assume the spirit of the hunter, calm and steady at first, but as they continue stalking their targets they grow more excited and hungry, therefore when they finally get to the target they torture them like they because of the lust of the hunter.
Kanaima drink the corpse as a way to satisfy their predatory hunger as well as for the benefits of it that aren’t really elaborated upon other than a longer lifespan and some other stuff.
Again the knowledge on Kanaima here is probably full of blinds and half-truths given to the writer by the Kanaima themselves so the only true way to learn about their magic is from them directly.
As for the methods, they use poisons and curse bottles, as well as poisoned and cursed arrows along with causing fear in the prey to get the job done, and a stick to drink from the corpse once its decomposed.
Maybe there is a sort of invocation/shapeshifter aspect to it on the unseen level. If they had made themselves alike somehow to wild predators and/or violent scavengers, then drinking the rot juice bacteria might not affect them, just like it doesn’t sicken the animals that do the same. And perhaps the auto-digestion jazz prevents the cannibal disease Kuru, that human cannibal tribes often get from eating too much fresh human brains.
And didn’t the TV show “Teen Wolf” use that term at one point for a reptilian shape-shifter style creature with paralyzing venom and a background of having murdered a kinsman or parent. I wonder what, if anything, the show creators kept from the folklore of these actual Shamans
Yeah, I realize that anything we read from a Western anthropological perspective about this is gonna have its own particular bias and blinds due to incomplete information being given to the author and filtered through his belief system. Still damned fascinating, though.
Do you remember if the author goes into detail as far as the background mythology/origin story of the possessing Kanaima spirit, or is his emphasis more that these are acts done completely voluntarily on the part of the predator-shamans?
Could be. Apparently Kuru can only be contracted from eating the brains of previously infected humans or by coming into contact with open wounds or sores on someone who’s infected with it. In other words, you have the highest risk of getting Kuru if you eat the brain of or come into contact with the sores on another cannibal. From my limited understanding, I don’t think that the general population of the Guyanese highlands (the potential victim pool of the Kanaima shamans) were cannibals, so unless the Kanaima are preying on themselves as well, they probably wouldn’t have to worry too much about Kuru.
Spiritually speaking though, cannibalism is fascinating. Experiments have shown that the memories and learned behavior of flatworms are somehow transferred to new flatworms after they eat the ground-up bodies of the old ones (presumably through the transmission of m-RNA). One can only assume that a similar process would take effect upon consuming another human’s brain: would one instantly have access to their memories and any supernatural power that they had accumulated? 
The origin is that it was a practice that started before time, brought about from the predatory parts of existence and therefore for the worship of it.
The best worship isn’t emulating something, its to be that something.