Entity 19 - The Backrooms Wiki (2024)



Table of Contents


Evolution and symptoms

Stage 1 - "Peaceful Phase"

Stage 2 - "Hidden Phase"

Stage 3 - "Complication Phase"

Stage 4 - "Necrotic Phase"


Patient zero

Entity 19, informally known as the Disease, is a highly transmissible bacterium via airborne particles and infected blood. It induces Disseminated Intravascular Coagulation (DIC)1, which, in the most advanced stages, leads to profuse bleeding and necrosis. According to the records and other files found on Level 109 by the Doctors when they arrived in the level, this disease largely predates the creation of the M.E.G., with patient zero having been discovered around a hundred years ago.


Entity 19 - The Backrooms Wiki (15)

A photograph of Entity 19 under an optical microscope (gram staining).

The Disease (scientific name Staphylococcus liminalis) is a bacterial species discovered a hundred years ago when an infected patient arrived for treatment on Level 109. It is a species derived from the Staphylococcus kind2, inducing septicemia of thrombo-embolic origin3. It can infect not only humans but also certain animals and entities. Infection may occur by breathing contaminated air or by contact with blood contaminated with strains of the bacterium4. The bacterium can be found in damp places and thrives particularly well in environments ranging from 24°C to 40°C. As explained above, the Disease causes the formation of blood clots that block blood vessels. This leads to hemorrhaging coupled with hemophilia, and necrosis of limbs and organs that no longer have blood flow due to the clot-induced blockage of blood vessels.

Evolution and symptoms

The Disease is contracted by bleeding on a level where the entity is present (see "Presence" section below). It can also appear if the wanderer breathes in an abundant quantity of the latter, as in an environment close to an infected corpse or another wanderer in the later stages of the disease. Its evolution can be divided into four stages:

Stage 1 - "Peaceful Phase"

The Peaceful Phase occurs just a few hours after the initial infection. During this stage, the bacteria cause a minor inflammation of the area around the wound, resulting in a slight reddening of the skin, a dull, nagging pain, and slightly increased local heat. This inflammation is caused by the mobilization of phagocytes5, which come to eliminate the strains of Entity 19. To protect itself from destruction by the body's defences, Staphylococcus liminalis produces a molecule called liminatidin. This has two effects on coagulation. Firstly, it mimics the action of Willebrand factor6. This has the effect not only of closing the vascular breach more quickly but also of forming additional platelet clusters suspended in the blood. As the presence of these platelet clusters risks clogging blood vessels and disrupting blood flow, phagocytes will come to destroy them and thus be distracted, "forgetting" the presence of liminalis.

Symptoms at this stage are almost non-existent. If the infected wanderer does not expect to contract the disease, it is almost impossible to notice the difference in clotting speed. Additionally, many things can mask the symptoms in the Peaceful Phase, such as pain from wounds. For this reason, it is advised to seek immediate treatment for any injuries in sustained warm and damp levels, even if no symptoms seem to be present. The disease cannot be cured at later stages.

Stage 2 - "Hidden Phase"

During this stage, the liminatidin will continue its effect, forcing the creation of blood clots despite the vascular breach being already obstructed. The phagocytes will continue to try to destroy them, giving the bacteria time to multiply. This multiplication of bacteria will produce more liminatidin, leading to more blood clots that are more and more important in size, and therefore harder to destroy by phagocytosis. It is during the Hidden Phase that liminatidin exerts a second action in the process of hemostasis7. It inhibits the action of plasminogen activators.

Entity 19 - The Backrooms Wiki (16)

Schematic diagram of liminatidin's action on the fibrin decomposition process (platelet clusters).

Under normal circ*mstances, this molecule would eventually destroy platelet clusters, thus preventing them from clogging blood vessels and, in turn, proper blood flow to the body's organs. However, in this case, this control mechanism cannot be activated, preventing coagulation from taking place.

It is during this stage that the immune system as a whole begins to fight the infection while continuing to destroy the platelet clusters. This will result in inflammatory reaction-type symptoms (redness, heat, pain, or swelling), which this time are visible because they are much more widespread throughout the body. At this stage, it is still possible to manage the Disease, as the patient is not yet truly contagious and the immune system, though fighting a futile cause, is not yet overwhelmed.

It is possible to assist the immune system with a strict diet consisting of Royal Rations and Almond Water, which will invigorate the immune system. Nevertheless, survival is dependent upon how developed the Hidden Phase is. Statistically, 70% of patients who receive treatment early on into the Hidden Phase will make a full recovery from Entity 19, whereas towards the end of stage, this number decreases to only 20%. If you have any suspicions of infection, please refer to the "care and prevention" section of this article.

Stage 3 - "Complication Phase"

As the name suggests, it's in the third stage that the prognosis really begins to look life-threatening. The clots continually produced by the Disease's secretions begin to obstruct the blood vessels. These vessels dilate in an attempt to let blood through (vasodilatation), causing severe reddening of the skin. Certain limbs become less innervated as the blood struggles to pass through the platelet clusters, which are destroyed more slowly by the immune system due to their quantity throughout the body. This is why, at this stage, most affected wanderers report that they can no longer feel their fingers or feet. Furthermore, the most infamous symptom of infection at this stage is the opening of blood vessels. It occur when they dilate so much that they burst. The infected wanderer will then begin to bleed profusely from various places, including the arms, legs and face. However, as most of the body's platelets are now clogging the blood vessels due to liminatidin, the body is unable to plug the many bursts, resulting in hemophilia8. The blood therefore continues to flow continuously from the individual's wounds.

At this stage, the symptoms are clearly visible. In addition to multiple hemorrhages, the infected wanderer will feel severe pain in the limbs and organs deprived of blood due to clots and bursted vessels. In addition, generalized fatigue begins to set in, along with the redness that persists even at this stage. Any attempt at treatment is unsuccessful, as the disease is too advanced for the immune system to fight. Furthermore, the blood released by the wanderer contains strains of Entity 19, making it extremely toxic upon contact. Since strains of the bacterium can remain airborne for up to a week in a humid environment, it is highly likely to breathe in large quantities and develop the disease while being around an infected corpse.

Only "palliative care" can be provided9, such as tourniquets. However, a wanderer in the Complication Phase must be considered lost and should not be approached under any circ*mstances because of the risk of transmission via the respiratory route.

Stage 4 - "Necrotic Phase"

This stage only appears if the wanderer has not already succumbed to their wounds. During the Necrotic Phase, limbs and organs that no longer receive blood will begin to necrotize. Hemorrhaging will continue, as do blood vessel tears. Moreover, the aggregates will begin to migrate to other organs, such as the lungs (which they can obstruct, causing breathing problems). This also happens to the brain, most often inducing a stroke leading to the wanderer's death. The wanderer will die either from blood loss or the death of one of their vital organs. An increased ammount of bacteria will become airborne, making the area become a biohazard. Behavior to adopt in this situation can be found in the treatment and prevention section.

It is vital to avoid all contact with anyone who has entered the fourth stage — if contact wasn't already being avoided. As in the previous stage, treatment is impossible. Do not attempt to terminate the victim's life in a way that will create a wound, such as a gunshot. Although this is noble and merciful behavior, it will only launch more bacteria into the air.

Treatment and prevention

Entity 19 - The Backrooms Wiki (17)

A laboratory technician performing a liminatidin test.

Although the Disease is incurable once it reaches stage 3, it can be managed if it is in stageq 1 and 2. However, as symptoms are extremely mild during these stages, it is required that patients take a test to confirm an infection by detecting the presence of liminatidin. If you have been injured in a hot or humid level or are experiencing slight lung pains, please go directly to Level 109 or the nearest M.E.G. base for testing. This could well be the difference between life and death for you and your companions. If you are unable to seek help, try to find Almond Water and Royal Rations so boost your immune system. You should also make sure to get adequate rest to allow your body to fight the infection.

The Backrooms Robotics firm recently launched the Red Light White Light test, which can be used to check food for the presence of bacteria. ADDENDUM - The "Red Light White Light" product from "Backrooms Robotics" is currently subject of considerable controversy, following the leak of classified documents, and so its effectiveness is no longer guaranteed. The M.E.G. strongly advises against the use of "Red Light White Light" until further notice.

As far as prevention is concerned, it is important to take care not to approach corpses of humans, animals, or entities. You are advised to not spend too much time in hot or humid environments. If you need to travel or stay in those types of environments, regularly consume Royal Rations and Almond Water to strengthen your immune system. Crystals of Firesalt can also be used to purify water or food if it is suspected of being infected with strains of the bacterium.

The Doctors are currently working with the M.E.G. to create a vaccine against the Disease on Level 109, but this is proving very difficult at the moment due to lack of material and knowledge. The most promising avenue at present is the use of contaminated plasma from Deathrats, who appear to be immune to the effects of the disease. Studies are being conducted to understand links between the Disease and other entities, such as with Sentient Aircrafts.


For a few months now, rumors have been circulating about the supposed beneficial effects of Aurora Liminalis on the evolution of the Disease. These are unfounded, as the phenomenon does not seem to consider diseases (including Staphylococcus liminalis) as injuries. It's important not to believe gossip and to stick as closely as possible to the official information in the database.


In view of the dangers posed by this bacterial species, the M.E.G. keeps an up-to-date list of levels with outbreaks of the infection. Nevertheless, please bear in mind that the summary table below is not exhaustive, as there are probably unknown outbreaks or undocumented areas with strains of Entity 19.

Level numberContaminated areasAdditional notes
Level 1Rooms with high humidityThe contaminated areas on this level are often those with particularly thick fog. These areas should be avoided at all costs and masks should be worn if such is not possible.
Level 2Segments of corridors over 24°C10While sources confirm its presence on this level, the latest reports seem to indicate that the epidemic has been eradicated here. Remain on your guard in the hot, humid areas of the level, however, as there is no such thing as zero risk.
Level 3Rooms with high humidityJust like the previous levels, humid areas in this location are to be avoided, and proper hygiene practices are strongly advised.
Level 3.1No specific areasThe measures to be adopted are the same as for the parent level.
Level 5The Boiler RoomIt is advised not to come into contact with the room's machinery, as the dampness of the walls is conducive to bacterial proliferation.
Level 109Biohazard RoomsThese rooms must not be opened under any circ*mstances.
Level 155Brick surfacesSimilarly to Level 5, it is not advised to come into contact with the wet surfaces on this level.
Level 173Warm lakesWhile the water is unfit for consumption, it can be purified with Firesalt crystals, if care is taken. However, this should only be done as a last resort.
Level 197Zone 3 - The Ruby ZoneIt is advised to leave this zone as soon as possible to reach the Turquoise Zone should the opportunity arise.
Level 571Floor 3This floor is the first to present itself as hostile on this level. As a result, and due to the presence of other entities on top of The Disease, its exploration is strongly discouraged.


It seems that Level 4 has recently been infected and an epidemic has started there. The bases have been quarantined as a precautionary measure, so it is not possible to approach them. M.E.G. teams are actively disinfecting contaminated zones of the level by eliminating corpses as well as sterilizing inhabited places. A temporary base had been installed about 1 kilometer (~0,6 miles) from base Omega, where it is possible to find liminatidin tests as well as hazmat suits that can be given under exceptional conditions.

Patient zero

Documentation of the Disease was only possible thanks to a collaboration between the M.E.G. and the Doctors. The latter is a group of doctors who rediscovered Level 109. During their explorations, they quickly came across rooms infested with Entity 19 at concentrations much more intense than what is typically seen in the Backrooms. Moreover, the hospital's abandoned appearance seemed to prove the theory of a disorganized escape by staff who had once worked there. These assumptions were confirmed by the discovery of the level's archives, which were created by a former group who worked in what they called "the Dimension of the Hospital". Although parts of this data had been corrupted over time, the most important information could be collected.

Patient zero of the Disease was a wanderer who had injured himself on Level 2 (named "Dimension of the Pipes" in the retrieved data) and came to Level 109 for a blood test. Nevertheless, this individual unfortunately spread the Disease to some staff members, possibly through his blood, which spread the bacteria airborne. The group was unprepared for a disease unknown to The Backrooms, which quickly led to an epidemic despite the hospital's infection control measures. Staff, as well as patients, were forced to flee through noclip portals that seemed to be much more stable and consistent than those of today. However, these people were not free of the disease, which allowed Staphylococcus liminalis to spread throughout the Backrooms.

There is still a great deal of mystery surrounding the emergence of this disease, particularly in terms of its creation. These documents have also raised new questions about the presence of colonies that predate M.E.G. It is certain that disorganization and lack of cohesion between small groups caused this succession of incidents, but questions remain about the knowledge and skills that these former colonies, now extinct, may have acquired.


1. i.e. Coagulation anomalies which causes the appearance of clots blocking blood vessels.

2. i.e. Gram-positive coccus in clusters.

3. i.e. A blood infection causing the appearance of clots in blood vessels.

4. For example touching your face with a previously contaminated hand, effectively introducing infected blood into the body.

5. A body defense system which digests and destroys foreign or dangerous elements.

6. A glycoprotein involved in platelet clot formation, i.e. the creation of a cluster of platelets at the level of the vascular breach.

7. The term "hemostasis" designates all the physiological phenomena that enable bleeding to stop

8. A coagulation abnormality of the blood that prevents it from clotting.

9. i.e. Treatments that only prevent symptoms, but have no influence on the progression of the disease.

10. 75,2°F

Entity 19 - The Backrooms Wiki (2024)
Top Articles
Latest Posts
Article information

Author: Terence Hammes MD

Last Updated:

Views: 6480

Rating: 4.9 / 5 (49 voted)

Reviews: 88% of readers found this page helpful

Author information

Name: Terence Hammes MD

Birthday: 1992-04-11

Address: Suite 408 9446 Mercy Mews, West Roxie, CT 04904

Phone: +50312511349175

Job: Product Consulting Liaison

Hobby: Jogging, Motor sports, Nordic skating, Jigsaw puzzles, Bird watching, Nordic skating, Sculpting

Introduction: My name is Terence Hammes MD, I am a inexpensive, energetic, jolly, faithful, cheerful, proud, rich person who loves writing and wants to share my knowledge and understanding with you.