Stage Symptom Progression Documentation
1 Infection occurs with exposure to bodily fluids contaminated with SCP-940 eggs and/or larvae. While larvae at this point are too small to be seen by the human eye, microscopic testing has revealed eggs are typically no larger than 3 to 5 microns in diameter. SCP-940 larvae, the only stage of its life cycle with many organ systems necessary for survival prior to integration with a host, possess leg spans from 7 to 17 microns.
Infected culture of human blood containing parasite eggs
Eggs Noted in Circles
2 The first SCP-940 larvae to hatch will begin cannibalizing any unhatched eggs, then each other, in order to ensure only one larva develops into an adult within a given host. Hosts will often complain of abdominal and chest pains at this stage. Note: Cases of as many as five larvae reaching maturity within a single host, though rare due to competitiveness between larvae for a host and the enormous strain placed upon the host's body, have been documented. (See Incident-940-01, Subject 04)
Ultrasound of Hatched Parasites in Carotid Artery
Larva Noted in Circles
3 The remaining SCP-940 larva migrates to the chest cavity, typically attaching to a major artery, the heart, or spinal cord, positioned with its legs oriented toward the host's back. Internal organ systems of the larva begin atrophying.
Death caused by severe heart infestation
Subject died of a stroke caused by break down of internal body, consistent with transition to Stage Four
4 The carapace of SCP-940 larva's body breaks down; legs remain intact. The circulatory system of the larva conjoins with that of the host, as does its nervous system, though to a lesser extent. The larva begins producing a number of enzymes which cause the host's body to increase production of a number of hormones, including human growth hormone. Earlier abdominal and chest pain subsides. The host experiences an increase in appetite and general listlessness.
MRA Image of Parasite Bonded to Abdominal Aorta
5 Approximately three weeks after initial infection, SCP-940 begins to alter serotonin and dopamine levels in the host's brain, causing hosts to experience feelings of happiness and well being. The legs of the larva, now supplied blood and nutrients by the host's circulatory system, begin to penetrate the skin of the host's back. Hosts typically do not report any discomfort or alarm at this, and rarely seek treatment.
Leg of Parasite Beginning to Penetrate Back
6 Approximately five weeks after initial infection, SCP-940 reaches full size and maturity. Hosts are secretive about their condition. A form of communication is believed to occur between SCP-940 and its host; for example, hosts have displayed a vague awareness of things occurring behind them. SCP-940 specimens often retract their legs, folding them flat against the host's back, allowing them to be concealed with relative ease by clothing. Additionally, SCP-940 triggers an increase in the levels of testosterone in the host's body, leading to increased libido. Infection of new hosts is facilitated through contact with bodily fluids contaminated with SCP-940 eggs; this is usually accomplished via coitus with an infected host.
Infected Semen Sample recovered from exposure during Incident 940-02
Eggs are generally invisible in female vaginal fluid (See Report 940-01-04 and -05 for more information)
7 All infected individuals that have survived six weeks of infection are considered to be in Stage Seven. Stage Seven infectees report the loss of a sense of individuality, gradual clouding of the eyes leading to loss of eyesight and culminating in near total blindness, and bouts of catatonia and catalepsy. Death is typically due to aneurysm caused by skyrocketing blood pressure, heart or kidney failure, or exsanguination. Infected at this Stage can be identified by the strange 'choking' sound they issue as they attempt to draw in more oxygen than is possible. When the host biologically dies, SCP-940 will continue to animate the corpse by means of its limbs, entering a 'berserk' state. In this state, SCP-940 will attempt to reproduce and infect with no regard for concealment, generally inflicting physical violence and blood transmission to do so. This state can last from one to three days before SCP-940 expires.
Image from Breakout at Area-14 Containment Facility.
Image Redacted by O5-12