Disease

Note: This article is about treatable illnesses. For physical damage, see Injury. For other health conditions, see Ailments.

Colonists sometimes contract diseases. These can occur through random events that vary by biome and difficulty (except for infections, which have a random chance of developing from an injury).

Effects

Diseases cause infected colonists to suffer symptoms, which can vary from diseases to disease. Diseases progress through stages of intensity until either the colonist develops or the disease runs its course, usually leading to death. Diseases progression generally follows a pattern of minor -> major -> extreme. The more severe the disease, the more dramatic the symptoms.

Treatment

At regular intervals, a resting colonist can be treated by a doctor. This slows the progression of symptoms, and for most diseases it is very important to treat the colonist as often as possible. You cannot give a new treatment until the last one has expired, and you can see the remaining time by hovering over the disease in the colonist's health tab. The treatment interval varies for each disease.

Treatment Quality is determined by a variety of factors, including the doctor's skill and the quality of medicine used.

Immunity: Colonists will gradually develop immunity to some diseases, such as infections or plague. When immunity reaches 100%, the symptoms will not immediately disappear, but the colonist is safe and no longer needs any treatment. If the disease symptoms progress past "extreme" before immunity reaches 100%, the colonist will die. Immunity Gain Speed is affected by the colonist's food, rest, bed quality, age, and blood filtration.

Blood Filtration is a major factor in getting better from diseases. Poor blood filtration may result in sicknesses developing more than they would usually. Older colonists are more susceptible to sickness than younger ones. Colonists with only one kidney have their blood filtration reduced by 50%.

Diseases

Most diseases have the following:

• General Symptoms - initial symptoms that develop in the first few days of being sick.
• Advanced Symptoms - symptoms that set in when the disease progresses for any reason (eg. being untreated or gets worse).
• Treatment - some illnesses are treatable with medicine, but not all diseases are treatable.

Flu

Main article: flu

Plague

Main Article: PlagueThe Plague is a deadly disease that affects both humans and animals. It progresses at a fast rate, killing untreated creatures within days from discovery. It can be caught in any biome.

Overview

Plague is a disease that is rapidly fatal for humans. If left untreated, it kills in 1.5 days, but rest and good treatment can slow the disease to the point where it takes 3 days to kill. It takes around 2.121 days to develop immunity to the plague - assuming the affected colonist is rested in an ordinary bed for the whole time, has normal blood filtration, is well-fed, and under the age of 40. Animals are more resistant to the disease, but still need treatment.

A skilled doctor, medicine, and healthy Blood Filtration organs (kidneys and liver) are critical to survival. The bonus immunity gain speed could mean the difference between life and death.

Prevention

Penoxycyline prevents colonists from falling sick to the Plague, but does nothing to stop an infection already in progress.

Stages

Extreme (Initial) and Extreme (Advanced) both display as just "Extreme" ingame, but have different symptoms.

Minor

• +20% Pain
• −5% Consciousness
• −5% Manipulation

Major

• +35% Pain
• −20% Consciousness
• −20% Manipulation

Extreme (Initial)

• +60% Pain
• −30% Consciousness
• −30% Manipulation

Extreme (Advanced)

• +85% Pain
• −30% Consciousness
• −30% Manipulation
• −15% Breathing
• Death at 1 severity.

Progression

Stages

This disease is detected immediately. Severity goes up over time, and is slowed by treatment until immunity is reached.

• Minor - Severity: 0 - 0.59
• Major - Severity: 0.6 - 0.79
• Extreme (Initial) - Severity: 0.8 - 0.9
• Extreme (Advanced) - Severity 0.91 - 0.99
• Death - Severity 1

Humans

• When not immune, severity increases by 0.666 per day.
• When immune, severity decreases by 0.333 per day.
• Immunity increases by 0.5224 per day when sick.
• Treatment slows progression by a maximum of 0.3628 per day.
  • This means the disease will progress by 0.3032 per day at 100% tend quality.

Animals

Animals can face the same disease, but their immunity increases faster, and treatment slows progression more.

• When not immune, severity increases by 0.666 per day.
• When immune, severity decreases by 0.333 per day.
• Immunity increases by 0.6092 per day when sick.
• Treatment slows progression by a maximum of 0.4254 per day.
  • This means the disease will progress by 0.2406 per day at 100% treatment.

Treatment

Ensure the afflicted pawns get as much bed rest as possible by prioritizing 'Rest until Healed', and get them the best medical treatment available. For humans, treatment is administered once every 15 hours. For animals, treatment is administered every 48 hours (2 days).

On a constantly resting, well-fed pawn with 100% Immunity Gain Speed, you'll need at least 15% average treatment quality to slow the plague's progression down sufficiently so that it doesn't kill the victim.

Vulnerable

For humans with a base Immunity Gain Speed of 47% or less, there is no chance that they will be able to survive the plague normally, even with 100% treatment quality for all treatments and rest in a hospital bed with vitals monitor connected. This includes very old people over the age of 120, and some people with kidney and liver damage (physical or chemical). A colonist with poor rest or treatment quality may also be on the verge of death.

To save a colonist on verge of death, you can do the following:

• Administer healer mech serum - instantly treats the disease
• Administer luciferium - if pawn has 28% or more immunity gain speed remaining initially, this gives pawn a chance to survive
• Use the medic cycle of the Biosculpter pod - if used early enough, the pawns can bring themselves to it

Malaria

Main Article: Malaria Malaria is a potentially fatal disease that can be contracted by colonists in any biome, but is frequent in the jungle.

Overview

General symptoms include impaired consciousness, blood filtration - and eventually pain, vomiting, and impaired manipulation. Advanced symptoms include frequent vomiting along with a loss of consciousness, and death. As Malaria affects blood filitration, the pawn's immune system becomes less effective as it progressive.

If left untreated, Malaria can kill the affected person in 2.701 days from discovery. It takes around 3.106 days to develop immunity to Malaria; assuming the affected colonist is rested in an ordinary bed for the whole time, has nothing else affecting blood filtration, is well-fed, and under the age of 40. These figures are calculated assuming 91.35% blood filtration (the 'average' blood filtration throughout all stages of the disease); due to Malaria's nature, there's no reliable way to calculate the time to develop immunity.

Prevention

Penoxycyline prevents colonists from falling sick to the Malaria, but does nothing to stop an infection already in progress.

Stages

Minor

• -10% Blood Filtration
• -5% Consciousness

Major

• Vomiting every 1.5 days (36 hours) on average.
• +30% Pain
• -20% Blood Filtration
• -12% Consciousness
• -8% Manipulation

Extreme

• Vomiting every 0.75 days (18 hours) on average.
• Loss of Consciousness
• +30% Pain
• -22% Blood Filtration
• -10% Manipulation
• Death at 1 severity .

Progression

Stages

This disease is detected immediately. Severity goes up over time, and is slowed by treatment until immunity is reached.

• Minor - Severity: 0.0 - 0.77
• Major - Severity: 0.78 - 0.9
• Extreme - Severity: 0.91 - 0.99
• Death - Severity: 1

Humans

• When not immune, severity increases by 0.3702 per day.
• When immune, severity decreases by 0.7297 per day.
• Immunity increases by a base rate of 0.3145 per day when sick.
• Treatment slows progression by a maximum of 0.232 per day.

Treatment

See also: Immunity Gain Speed

It's especially important that affected colonists are rested while they fight off Malaria due to its effect on Blood Filtration, and that you have plenty of medicine and a skilled doctor in hand. As with any other disease, you'll also want to make sure that the patient is well fed, rests as much as possible, and that they're promptly treated.

Treatment is administered once every 12 hours. On a pawn that constantly rests, with 100% pre-Malaria Immunity Gain Speed, you'll need at least 7% average treatment quality in order to sufficiently slow down Malaria's progress to the point where it doesn't kill the patient. With a hospital bed and vitals monitor, colonists can survive without treatment. However, this is far slower than treatment, even without medicine.

Vulnerable

For those with a base immunity gain rate of 37% or less, there is no chance that they will be able to survive malaria normally, even with 100% treatment quality for all treatments and rest in a hospital bed with vitals monitor connected. This includes people well past their Life Expectancy, and/or people with kidney and liver damage. Malaria can also be deadly if a pawn does not get enough treatment or rest.

To save the colonist, you can do the following:

• Administer healer mech serum - instantly treats the disease
• Administer luciferium - if pawn has 22% or more immunity gain speed remaining initially, this gives pawn a chance to survive
• Perform an organ transplant for pawns with damage to their liver or kidneys. There are no direct artificial replacements for these organs, so you will have to acquire a "donor".
• Install up to two immunoenhancers for 8% per enhancer installed. Note that these require a kidney to be present for them to be installed into, so a transplant might be required if they are missing. Damaged kidneys are sufficient however.
• Use the medic cycle of a Biosculpter pod.
• Place the patient in a cryptosleep casket until you have one of the above.

Version history

In an earlier version (Alpha 17?) sufficiently good treatment could cause malaria to regress. This combined with the fact that malaria had a hidden stage back then meant that the disease could be "cured" and subsequently reappear several times, until the pawn finally gains immunity.

Infection

Main Article: Infection

Infection is a very quick disease that can be contracted from open wounds.

Overview

Infections can occur on most wounds. It is the fastest working illness in RimWorld, taking little more than a day to kill the victim if left untended. Animals can also contract infections, moving just as fast as human infections, although it is at a reduced chance.

It is possible to have multiple infections simultaneously across different body parts. Each infection progresses at its own rate, while immunity against infections progresses at the same rate across the whole body. If the patient can become immune before the worst infection reaches 100%, that now-immune patient has beaten all their infections.

If untreated, the patient loses this race in less than a day and a half, so any infection needs to be treated immediately and constantly. A pawn with 100% Immunity Gain Speed will become immune in around 1.5 days.

Mechanics

Any cut, bite, burn or frostbite has a chance to become infected; blunt traumas (aka bruises) do not, nor can a pawn get an infection from losing a body part (i.e. a hand cannot become infected because of a lost finger). The chance of a pawn getting an infection depends on the wound type and various other factors:

• Bite, burns, and chemical burns have a 30% chance.
• Frostbite has a 25% chance.
• Shredding injuries have a 20% chance.
• Most other bleeding wounds have a 15% chance.
• Bruises, cracks or missing parts cannot be infected.
• Colonists are more likely to get wound infections at higher difficulties.

Treated wounds can still get infected, at a reduced chance. The multiplier is 85% at 0% tend quality, and linearly decreases to 5% at 100% tend quality. Animals have 20% of a colonist's chance to get an infection. Cleaner rooms further reduce the chance of infection. A regular room without any dirt has a 50% multiplier, a clean room with sterile tiles has a 32% multiplier, while caravans and outdoor spaces have are 100%.

When a colonist has an infectable wound, the game will count down randomly from 15,000 ticks (4.17 mins) to 45,000 ticks (12.5 mins). The game will also keep track of if the wound was tended, and, if so, what percent chance of an infection would arise from the room stats and the tend quality. Once it reaches this timer, it will decide if the wound will be infected, based on that percent chance. Once an infection sets in, it immediately becomes a life-or-death race between the infection rates vs. the patient's immunity progression; the first to a value of 1.00 (100%) "wins".

Prevention

The Perfect immunity gene will completely prevent infections. However, creating a xenogerm with it requires an archite capsule, so modifying every pawn with it is expensive. For pawns without the gene, the chances of infection can be greatly reduced. Make sure to tend to people/animals quickly, in a clean/sterile environment. Any constructed floor is better than dirt, and sterile tiles are better than generic floors. You should also have pawns clean the room in question. See cleanliness for more details.

A triage area can be established near a killbox to tend to pawns quickly without having to trudge halfway across the map carrying the pawn to tend - the utility of this depends on the distance to a hospital and the number of pawns needing treatment. More pawns and larger distance make it more relevant, while a single pawn getting downed in the room next to the hospital would be better off taken to the clean room.

Progression

Infection and immunity progression begin as soon as the disease is detected; the first to 100% (1.0 severity) "wins", either saving or killing the pawn. The current status of both progressions can be viewed in the sick colonist's Health tab by mouse-hovering over the word "Infection". Unfortunately, the disease progresses faster without good treatment and rest.

Note that the immunity only applies to the current infection, not future infections. Any new infection will cause the process to begin again from scratch.

Stages

Stage	Severity	Symptoms
Infection (minor)	0% - 32%	Pain: +5%
Infection (major)	33% - 77%	Pain: +8%
Infection (Extreme)	78% - 86%	Pain: +12% Consciousness: −5%
Infection (Extreme)	87% - 99%	Consciousness: Max 10% (Unconsciousness) Pain: +85% Breathing: −5%
Infection (Extreme)	100%	Death

Humans & Animals

• When not immune or treated, severity increases by +0.84 per day (+0.035 per hour).
• Treatment slows progression by a maximum of −0.53 per day (less with poor treatment).
  • At 100% treatment, the disease will progress by +0.31 per day.
• When immune, severity decreases by −0.7 per day.
• Immunity increases by +0.6441 per day when sick.

This means that an infection can kill less than 1.19 days from first symptoms. A pawn with 100% Immunity Gain Speed will become immune in 1.55 days on average - meaning that they will die without treatment slowing severity gain or improving IGS to at least 130.4%. Note that this ignores the effect of InfectionLuck. For a full breakdown on Immunity Gain Speed and the factors that affect it, see that page.

Case studies

• It has been observed in patients with normal beds, a room with "slightly dirty" to "dirty" cleanliness, well nourished, Medical care with skill ~6-10 and only herbal medicine (Tend quality ~40-50), will recover from their infections, even despite some few hours delay in starting treatment. It sometimes is a near thing, and may result in a longer recovery time from an end infection near/over 90% when they reach immunity, depending on the delay, their feeding schedule and the "luck" of the attending doctor. Malnutrition (from hunger) definitely slows the immunity process, as listed under Immunity Gain Speed.

• It has also been observed that a prisoner in good health (age < 50, no health issues), well fed, in an excellent-quality hospital bed with a vitals monitor, and a Tend quality of 99% (high Medical skill using glitterworld medicine), gained Immunity more than 2:1 over Infection gain (from a 68 Immunity and 83 Infection, +32 v. +15). That's not a "maximum", but it may be close to a reasonably practical one, just as a benchmark.

All this math also means that it will take a patient almost 3 days, or more, to go through the process of first fighting and then recovering from an infection, besides recovering from whatever wound or ailment caused the infection in the first place. Yet another reason to provide prompt, sterile treatment for all colonists' wounds to avoid this in the first place.

Default warning

Toward the end of a bad infection, once the infection becomes "extreme" (80% or more), you will get a bright red warning among the other notices on the right side of the screen saying:

"Medical emergency People are at risk for death because of severe illness..."

This alert appears regardless of whether that colonist is currently beating the infection or not, or will do so - the game doesn't do the math to predict whether the infection or the immunity will reach 100% first, but you should be able to. The warning is simply there to remind you that now may be the time to take drastic action, just in case you are losing the race. The notice will disappear when immunity reaches 100% (regardless of the current level of infection), or when the victim dies.

Treatment

Prevention is the best treatment - a capable doctor and clean environment for treatment are critical to avoiding this deadly ailment before it happens. Even after successful treatment of a bad infection there can be a fairly lengthy recovery time, so prevention really is the best medicine in this case.

If left untreated, infections kill in a little over a day - untreated infections move fast! For resting colonists with 100% immunity gain speed and immediate treatment, you will need at least 15% average treatment quality to ensure that one doesn't succumb to their infected wound(s).

As with any other disease, make sure that the patient is rested, well-fed, and treated whenever possible. A single infection will take multiple treatments, administered once every 12 hours, per infection. Infections progress very quickly, and missing or delaying a treatment can be a very costly mistake. Due to the rate at which infections progress, you'll want at least a competent doctor using herbal medicine or better in order to ensure that the affected person survives an infection.

Once you beat the infection, that value then begins to (slowly) drop back to "0", from where ever it was; no further treatment is necessary once this starts. However, better treatment quality results will stop the infection before it progresses to a higher value, saving recovery time for the patient, so the more bonuses you can scrape together* during treatment, the faster the recovery.

(* better Medical skill, better medicine, a clean room, a higher quality bed, upgrading to a hospital bed, adding a connected vitals monitor, etc. See Doctoring for more details.)

This disease is unique in that it only affects a specific, isolated body part, making infections curable by removing that part. It is not possible to amputate vital organs, though some can be replaced with artificial versions. It's (usually) better to have a colonist missing a part or two than to lose the colonist entirely, and there is no mood debuff if you remove an infected part. If the infection has progressed to over 97%, there is little to no chance your surgeons can successfully pull off an amputation in time, so plan accordingly. As with any operation, amputations (and organ replacements) can fail, leaving the infected part attached, so if you make the decision to do this, try to operate before 90% or earlier, so you have time to try again.

• To amputate: Under the patient's Health tab is the Operations tab; "Add a bill" to amputate the infected body part. You may also have to/want to upgrade the patient's default "medicine" used for procedures - that's under their Health/Overview tab. If an arm/leg/kidney is the target, make sure to amputate the correct (left/right) part - surgeons just do what they're told.

Vulnerable

For those with a base immunity gain rate of 39% or less, there is no chance that they will be able to survive a wound infection normally, even with 100% treatment quality for all treatments and rest in a hospital bed with vitals monitor connected. This includes some people with kidney and liver damage (physical or chemical). A pawn with poor treatment or little rest may also be at risk of death.

To save the colonist, you can do the following:

• Administer healer mech serum- instantly treats the infection
• Administer luciferium- if pawn has 23% or more immunity gain speed remaining initially, this gives pawn a chance to survive
• Amputation or part replacement
• A biosculpter pod's medic cycle

Version history

• 0.7.581 - Added.

At around Beta 18 infections caused a reduction in part efficiency, allowing them to kill much earlier than usual if a critically injured vital body part is infected and the infection causes the efficiency of that body part to drop below zero.

Sleeping Sickness

A parasitic disease carried by insects in the jungle biome.

It's notable that sleeping sickness takes a very long time to recover from.

General Symptoms:

• Impaired consciousness
• Impaired manipulation

Advanced Symptoms:

• Loss of consciousness

Treatment:

• Treated with medicine
• Treatment duration: 80,000 ticks (22.22 mins)

Gut Worms

A parasitic disease which doubles that rate at which colonists become hungry.

Can be contracted in the following biomes: arid shrubland, desert, extreme desert, boreal forest, tundra, temperate forest, and tropical rainforest.

General Symptoms:

• Increaser hunger rate (200% of base)
• Increased vomit rate (to average once per day)

Advanced Symptoms:

• None

Treatment:

• Treated with medicine
• Treatment duration: 120,000 ticks (33.33 mins)
• Treatment count: 5

Muscle Parasites

A parasitic disease hampering the muscles.

General Symptoms:

• Impaired manipulation (-30%)
• Impaired movement speed (-30%)

Advanced Symptoms:

• None

Treatment:

• Treated with medicine
• Treatment duration: 120,000 ticks (33.33 mins)
• Treatment count: 5

Fibrous Mechanites

A Mechanoid disease which brings mild pain in early stages but boosts several attributes.

General Symptoms:

• Tiredness (*170%)
• Mild pain (+0.2)
• Improved manipulation (+50%)
• Improved movement speed (+50%)
• Improved blood pumping (+50%)

Advanced Symptoms:

• Intense pain (+0.6)
• No additional stat boosts over early stages

Treatment:

• Treated with or without medicine, though medicine speeds up recovery
• Treatment duration: 120,000 ticks (33.33 mins)
• Can disappear without treatment as early as 900,000 ticks (250 mins)
• Can last without treatment as long as 1,800,000 ticks (500 mins)

Sensory Mechanites

A Mechanoid disease which brings mild pain in early stages but boosts sensory perception.

General Symptoms:

• Mild pain (+0.2)
• Improved sight (+50%)
• Improved hearing (+50%)
• Improved talking (+50%)
• Improved manipulation (+30%)

Advanced Symptoms:

• Intense pain (+0.6)
• No additional stat boosts over early stages

Treatment:

• Treated with or without medicine, though medicine speeds up recovery
• Treatment duration: 120,000 ticks (33.33 mins)
• Can disappear without treatment as early as 900,000 ticks (250 mins)
• Can last without treatment as long as 1,800,000 ticks (500 mins)

Disease Frequency

Disease frequency by difficulty

Difficulty	Disease interval multiplier
Free Play	3
Basebuilder	1.5
Rough	1.0
Challenge	1.0
Extreme	0.9