Item #: SCP-150
Object Class: Keter
Special Containment Procedures: SCP-150 patients kept for study should be contained in Level-3 Biohazard Containment Cells, with no more than 1 instance per cell. Cultures of SCP-150 are contained in vacuum-sealed glass flasks in the Site-42 infectious materials lab. Standard pathogen-handling procedures should be followed at all times. Any instances of SCP-150 found outside of containment are to be incinerated.
Description: SCP-150 is an obligate parasite that resembles the tongue-eating louse (Cymothoa exigua), but is adapted to form conjunctive symbiotic relationships with humans for a period of its lifespan. Upon contact with a human subject, SCP-150 embeds itself deeply in the flesh of its host. Over the course of approximately seven days, the parasite will burrow into the host and affect numerous physiological alterations.
The most glaring alteration is the gradual conversion of the limb nearest the infection site into a chitinous appendage: as SCP-150 consumes the host's flesh, it excretes tissue that replaces and augments the functionality of the host's limb without causing transplant rejection. It is suspected that SCP-150 is able to secrete anesthetic and immunosuppressant substances to prevent the host's body from responding to the change. Furthermore, the nervous tissue excreted by SCP-150 is able to interface with the host's nervous system. By the time the process is complete, the host will be able to control the affected limb with no loss in mobility and often with improved strength, reflexes, and resilience.
For a period of one to two weeks, SCP-150 will reproduce, feeding on nutrients from and depositing eggs1 into assimilated blood vessels. The eggs are deposited throughout the human body via the bloodstream - while the vast majority of them die off, enough survive to begin colonizing and altering the rest of the host's body. Though subjects report discomfort and occasional loss of motor control during this process, they often will not recognize the cause of said discomfort. It is still unclear why the offspring do not compete with each other for space or resources, nor how the assimilation process leaves the body's cell signaling mechanisms and processes unaffected. SCP-150 reproduces during this assimilation process: as the lungs are assimilated, more eggs are produced and spread by the patient's coughing. Although as many as 10,000 eggs may be produced during this time, it is estimated that only 1% of them find their way into another host, of which 1% survive the host's immune response and implant successfully.
Although SCP-150 inevitably results in the assimilation and alteration of the central nervous system, including the spinal cord and brain, the host's consciousness and behavior are seemingly unaffected. Interviews with subjects infected by SCP-150 have yielded little information, as infected subjects unaware of SCP-150 claim to sense no changes or improvement in certain senses and faculties. While subjects aware of the infection are able to pinpoint the source of the change, they exhibit little to no negative feelings and often express positivity towards it.
Addendum 150-E: Transcript of Exploratory Leukotomy and Nervous Tissue Transformation Experiments
Two D-Class subjects, D-13732 and D-016002, were infected with SCP-150 and allowed to progress through all stages of the infection. In order to examine the full effect of the infection, exploratory neurosurgeries were performed on both subjects. D-13732 was euthanized; his nervous tissue was found to have been entirely replaced by smaller instances of SCP-150. The instances comprising his brain matter were extracted and stored for experimentation on D-016002.
