New illnesses - ones that are emerging now - are mostly created on purpose. Strange new life-forms, bacterias and mycoplasmas and parasites are developed in places like the USA army labs.
One of the USA army patented products was famously described as "designed to disable, not kill". Lots of applications for something like that, like a cheap labour force that won't have the energy to protest bad conditions. {That could be us right here right now - are you protesting the crap all around us, or "just going to work and trying to keep it together cuz you feel way in over your head right now"}
Strange new fibres emitting from the lip of a child were first seen recently, and are describved in this webiste dedicated to looking into this strange new skin disease.