Hello I'm looking for the title to a sci-fi short story I read years ago. Here are a couple of details I remember:
- Humans fight a war with an alien species that develops a neurological parasite as a bioweapon.
- The parasite's physical form is a shiny blob that enters through the mouth.
- The parasite is given the ironic designation of a "symbiotic parasite."
- Once infested, even with immediate medical help, the human is left a husk of his former self.
- Infected humans are unable to kill themselves as the parasite will over-ride self-destructive actions for the purposes of self preservation.
- The protagonist and his friend serve in the front lines and make a promise that if either of them become infected, the survivor will kill the other to put him out of his misery.
- The protagonist's friend becomes infected, but can't bring himself to kill his friend and ends up calling for medics instead.
The main part of the story takes place years later after the friend is infected when the protagonist runs into his infected friend once again. Only this time, the protagonist realizes the consequences of letting his friend live when he sees the agony his friend is in. And the main conflict revolves around the protagonist attempting to secretly kill his friend so as not to activate the parasite's self-defense reflexes.
If anyone has read this story and can give me its title and author, that would be fantastic. Thanks for the help!