This article on microgravity biology suggests a space plague can be carried by us on the stations, developed by our own bacteria laden selves. Will space humans of the future need special structures implanted in them? Discussion needed.

https://microbewiki.kenyon.edu/index.php/Bacterial_response_to_microgravity

good questions, but I think that you can play in terms of prevention measures for these problems, due to the fact that no e.coli neither salmonella grow on steel or titanium plates (maybe clostridium tetani or if we borrow soil for cultivation, but even here we can prevent)