Okay, so I know that severe, life-threatening illness such as rabies which has a 100% chance of death without treatment and Ebola which has a 50% chance of death would not be allowed because that would lead to a massive die-off, regardless of if the immunity to the ebola virus is passed down to offspring or not.
But obviously death rate alone shouldn't be the only factor. Some illnesses have a low enough death rate but become chronic and/or need complex treatment. TB is a perfect example of this. The death rate is around 16% for those who are diagnosed. Okay so that is way higher than the flu which is around .45% of those diagnosed but it does require complex treatment(multiple antibiotics for months), especially for the drug resistant TB. And even then, it can be a chronic illness with a potential for relapse after antibiotics are stopped.
So TB is no-go. Parasitic illnesses are often severe though maybe a few milder skin and intestinal parasites should be allowed(I specify skin and intestinal because those are more likely to be mild than other parasites like for example Plasmodium spp.).
Fungal I think should be allowed along with most viral illness(chickenpox, cold, flu, gastroenteritis, etc.).
Bacterial is really the area that I don't know whether or not it should be allowed. I mean you've got everything from Group A streptococcus which can cause flesh eating disease, strep throat which is followed by scarlet fever and potentially rheumatic heart disease if untreated, impetigo, and toxic shock syndrome to TB which like I said earlier is an illness that can be chronic and has to be treated with a months long course of antibiotics.
Of course if someone has an illness from prions(which are just misfolded proteins that cause normal proteins to become misfolded) that shouldn't be allowed either regardless of the only transmission being eating food that is infected with the prion.
The reason I think illness should be allowed is simple. To keep the immune system at its prime so that nobody dies from an illness that is mild on the destination planet. Without any illness exposure, 3 things will result. Those are:
- Autoimmune disease
- Weakened immune system which can't handle even a mild viral infection
So when I decide which illnesses are allowed and which aren't, should I take into consideration both transmission and pathogen as well as severity, death rate, and treatment?
Okay, let me clarify why I think illness should be allowed and also why severe illness shouldn't in my opinion be allowed. Yes the people are high in technological progress including medical treatment. But drug resistance is always a threat when treating a bacterial illness. Antibiotics themselves can also lead to illness by killing the good bacteria. So for example, yeast infections are a common side effect of taking antibiotics. The longer the antibiotic treatment, the more likely the bacterial illness is gone but also the more likely someone will get a yeast infection or other illness as a result of the antibiotics. Viral illnesses are typically mild enough to have supportive care be the only treatment needed. Of course there are exceptions such as Ebola, rabies, and HIV. As for fungal infections, again a lot of them are mild and would simply require using an antifungal for x days. And with some intestinal parasites, it isn't any worse than severe diarrhea that goes away in a few weeks. That can be treated with hydration, electrolytes, and anti-diarrheal medication.
So should I allow at least some bacterial illnesses along with viral illness, fungal infection, and a few parasitic illnesses?