An experiment launched with the Cygnus 'craft brought my attention to another difference between Earth and space environments: human infections may become more lethal, more virulent, and less prone to antibiotic treatment in space due to microgravity (and also possible increase in rate of mutations).
A search through PubMed yielded a few interesting abstracts/articles, in two 'waves' (2004-2006 and 2012-2013).
How will a prolonged Beyond Earth Orbit (BEO) mission deal with antibiotic-resistant pathogens in terms of standard operating procedures, extra equipment and supplies required?
What are the implications of infections complicated by microgravity for in-flight surgical procedures?
How many researchers are active in this area across major space powers (NASA, the Chinese etc.)?