Contagion (basic)
Mechanical/AI mod that adds a tranmissible disease. Spreaders will spawn in the world with a low probability (1 in 100, because the parameter is an integer) and create new carriers. As per current implementation, people can be cured, and being infected grants somewhat of an immunity. You can’t eradicate it because wandering patrols will spawn spreaders.
This is only a skeleton and the only symptom is airway problems (an annoynance), but, it might mutate and quite easily (I’m saying that the mod can be edited. I haven’t coded a mutation into the mod, lmao). Have fun and stay safe.