A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The study of disease is called pathology.

Disease can be acute or chronic.

1   Herpes

See, there are two types of Herpes: HSV-1 and HSV-2. HSV-1 usually causes breakouts around the mouth — we just call them cold sores or fever blisters. Over 80% of the population has HSV-1, although at any given time almost none of us have a breakout. HSV-2 causes breakouts around the genitals.14 The majority of people never get breakouts or get such minor breakouts that they don’t even realize that it’s herpes. My friend who has had a breakout said that he originally thought his was just a bug bite. It wasn’t until a second one showed up that he decided to get it checked out. It’s been over three years and he hasn’t had another breakout since. He’s also in a monogamous relationship and his girlfriend has never had a breakout.

Herpes never goes away, but it’s relatively harmless. In fact, even if you do get breakouts, most people stop getting them after a couple years. And if you’re one of the unlucky few who actually does get bad break outs, you can take medication to suppress them. So there. Not worried about herpes anymore… After all, I probably already have it, and so do many of you.

2   HIV

HIV is no longer the death warrant it once was. Don’t get me wrong, contracting it would be awful and surely life-altering. But you would live. I just hope you have good health insurance. As of 2011, the life expectancy of someone who contracts HIV is 40 years from the day they contract it. When in doubt, just look at Magic Johnson.

There are some demographics which are far more likely to catch HIV than others, primarily gay men and drug users. 80% of all HIV cases come from gay men or drug addicts who use dirty needles. When it comes to vaginal sex, it’s almost impossible for a man to catch it from a woman, while a woman can catch it from a man. But anal sex seems to be the big culprit here.

Also, I hate to say it, but HIV positive cases are predominantly lower income classes. African-Americans account disproportionately for 42% of all HIV cases in the US. The disease practically doesn’t exist in Western Europe at this point.

The symptoms of HIV are flu-like symptoms a couple weeks after contracting it. From there your immune system slowly shuts down over the period of years. There are a lot of therapies and treatments available and most people who contract it are able to live functional, mostly normal lives, assuming they get the proper medical care. So the news on the HIV front over the past few decades has actually been mostly good.

3   Prion-disease

Prion disease has a case-fatality rate of 100%. That's not an estimate or approximation and it's not rounded up. They are also untreatable.

There are only five well studied prion diseases (because of their rarity). Two are exclusively heritable: fatal-familial insomnia and Gerstmann–Sträussler–Scheinker syndrome. One, Kuru, is transmitted via cannibalism.

The incubation times are extremely long. Some estimates for Kuru go up to 20-50 years.

The most prevalent form of prion disease in humans is new variant Creutzfeldt–Jakob disease (nvCJD) or Human Mad Cow which has a lag of about 10 years based on CDC data. It is transmitted by eating tainted beef products. Let me stress that this is extremely rare: there have been 3 confirmed cases in the United States.

It is extremely unlikely that Soylent is a vector for prion disease, especially since it's been vegan since version 1.2 and never contained beef as an ingredient. Even if it somehow contained tainted beef, given that it's been available for less than 3 years, it's extremely unlikely that any cases of nvCJD (of which there have only a few in the last decade) or any other cases of prion disease were caused by Soylent.