The Vocal Cord Parasites, or the "Curse of the Forked Tongue" as it is known by most, are a group of parasitic organisms that infect the victim's vocal cords. Their existence had been theorized by scientist George Dine as early as the 2150s. He discovered a parasite called "The One That Covers" in 2187, and these discoveries lead to the San Hieronymo Group talking Dine into recreating the Vocal Cord Parasites from that as part of their ethnic cleansing project. The project was shut down, however, after it wa deemed that targeting an entire language was too risky to be put to use.
In 2191, the Insurrectionists obtained the DNA coding from an ancient human cadaver excavated from a permafrost region on Earth and the reverse evolution of a relative species of Pentastomida. George Dine was kidnapped and forced to recreate the parasites. They were weaponized, and various strains were created that reproduced when exposed to a language spoken by their host.
In 2193, a Hungarian strain of the Vocal Cord Parasites was exposed to Cygnus II in the Cygnus Star System, which led to the entire planet being quarantined off. The host of the parasites must be either quarantined or killed to stop the infection from spreading. The bodies of the dead must be destroyed completely, or A. they will break down into soil and spread to living organisms in the soil, or B. be spread by animals.
Eventually, a "cure" was developed. Infecting the parasites with Wolbachia bacteria would cause them to change into females, halting their reproduction and keeping them from becoming symptomatic, but at the cost of the hosts' fertility. It would also leave the victim with PTVD, or Post-Traumatic Vocal Disarticulation, disabling their ability to speak. Children cannot be infected, but can act as carriers for it, as the parasites can only infect matured vocal cords.
Initially in larval form, the parasite enters through the throat and latches onto the vocal cords of the victim and mimics the membranes flawlessly. Upon reaching maturity, the larvae mate, triggered by sustained exposure to the specific language the parasite was attuned to, feasts on the host's lungs, killing them. As the victim dies, they enter a zombie-like state of dementia that violently works to ensure that the parasites are spread any way and as much as possible because they lose themselves. Once symptoms manifest, the alveoli is infested, disregarding any fashion of saving the victim. If the host does not speak, the parasites cannot mate, and therefore they do not infest or get spread.
Wolbachia can be used to infect the parasites, turning them into females and not allowing them to mate. The symptoms are halted, but renders the host infertile. Water contamination also prevents infection, killing off the parasites that enter it.
Living Organisms [spread by using the hosts' vocal cords]