Last night's sleep was particularly disturbed. Our daughter is feeling a bit under the weather (nothing too serious, but when you're only ten months old and you can't articulate how you feel to your sleep-deprived and worrying parents it must seem bad), and this got me thinking about illness in the Oort Cloud.
I don't think that disease will be a big portion of the setting, but there is always something particularly "What do we do?!" about a plague or a sickness that is going around. So it's at least fun to think about it.
We know that bacteria and viruses evolve quickly (relative to our own evolution, and even relative to our technological evolution). So it is reasonable to assume that there will be some infectious diseases in the future. Organisms want to propogate (in as much as they might have "motivations") so there are two options for thriving diseases hundreds or thousands of years from this point on (as I see it at the moment for the setting; I'm a doctor, but I'm not that kind of doctor, just thinking).
Option 1 is that there are diseases which are essentially symbiotic or at least non-problematic for people. Contagious colds that don't really bother people, but which stay around long enough to be passed on. Option 2 are things which we might liken to Hyper-SARS, things that get passed on, have a relatively high lethality and are really infectious. People die, quarantines are imposed - and that is a neat adventure hook perhaps, because there are all kinds of wants and needs that a quarantined population might have - and all kinds of problems that thrillseekers might need to work around to get paid.
There is a third option: I recall reading a few months ago about a bacteria that had been found in a space centre clean room. Shortly after the same (or a very similar) organism was found in another clean room at a different space centre. There was no possibility of any kind of cross contamination. The analysis was that this bacteria had evolved to survive in the aggressively sterile environments of clean rooms - and had evolved twice at two different locations.
Simply put, as I understand it, this bacteria had been trundling along for millenia, just there and then a niche came along when it could thrive. What kind of bacteria, I wonder, will thrive in habitats at the edge of space when they are given the opportunity? And how will they impact the humans in those environments?