Sleeping sickness

Sleeping sickness is a parasitic disease that can only be caught in the likes of Tropical Rainforests. Sleeping Sickness takes a very long time to develop, and also gain immunity to; so those affected by Sleeping Sickness will be in bed for a long time.

General symptoms include slightly impaired consciousness and manipulation, a small amount of pain, and eventually occasional vomiting. Advanced symptoms include a small-moderate amount of pain, more adversely affected consciousness and manipulation, more frequent vomiting, eventually a loss of consciousness, and finally, death.

If Sleeping Sickness is left untreated, it will kill the affected colonist in around 17.026 days from discovery.
Good treatment can slow the disease to the point where it takes 42.515 days to kill.

It takes around 18.93 days to develop immunity to sleeping sickness, assuming the patient is rested in an ordinary bed for the whole time, and under the age of 40.

Stages

Minor (Hidden) - Severity: 0 - 0.28

No effect on the affected colonist.
Buildup to the initial 29% disease head start that sleeping sickness has

Minor (Initial) - Severity: 0.29 - 0.4374

+2% Pain
-2% Consciousness
-2% Manipulation

Minor (Advanced) - Severity: 0.4375 - 0.624

+3% Pain
-4% Consciousness
-4% Manipulation

Major - Severity: 0.625 - 0.874

Vomiting every 3.5 days (84 hours) on average
+5% Pain
-15% Consciousness
-6% Manipulation

Extreme (Initial) - Severity: 0.875 - 0.9374

Vomiting every 1.75 days (42 hours) on average
+10% Pain
-20% Consciousness
-20% Manipulation

Extreme (Advanced) - Severity: 0.9375 - 1

Vomiting every day (24 hours) on average
Maximum 10% Consciousness
+15% Pain
-20% Manipulation
Death

Progression

When not immune, severity increases by 0.0417 per day.
When immune, severity decreases by 0.125 per day.
Immunity increases by 0.036 per day when sick.
Treatment slows progression by a maximum of 0.025 per day.
- This means the disease will progress by 0.0167 per day at this rate.

'Waking up' from Sleeping Sickness

Despite Sleeping Sickness' uniqueness in the respect that it's very slow to progress and conquer; it's not as difficult to successfully treat compared to other diseases such as malaria and the plague. However: you should still follow standard protocols and ensure that patients of Sleeping Sickness are rested at all times, well-fed, and promptly treated when they need to be treated. Like Malaria and the Plague, Sleeping Sickness can be prevented (but not treated) by Penoxycyline as of Alpha 17.

Treating Normal People (<40 Years Old)

You will need at least 18% average treatment quality in order to sufficiently slow down Sleeping Sickness' progress to the point where it doesn't kill the patient.

The following combinations of doctoring skill and medicine are capable of achieving 18% treatment quality (assuming a perfectly healthy, unmodified doctor, the patient is rested and well-fed at all times, and treatment is administered immediately) - you'll generally want to aim above these thresholds for safety though; these combinations are just the bare minimum required, and aren't guaranteed to work out:

Level 1 Medicine skill and glitterworld medicine
Level 1 Medicine skill and ordinary medicine
Level 3 Medicine skill and herbal medicine

Treating the Elderly (80+ Years Old)

As usual, you'll need to follow heightened procedures to ensure that the elders within your colony survive due to the 20% reduction in immunity gain speed that comes with being 80+ years old. You will need at least 56% average treatment quality in order for the affected individual to have a chance of surviving. Again, this is a bare minimum and you should generally look towards more potent combinations than the following in order for guaranteed survival: