The distinction between organic and inorganic carbon compounds, while useful in organizing the vast subject of chemistry... is somewhat arbitrary. Organic chemistry is the science concerned with all aspects of organic compounds. Organic synthesis is the methodology of their preparation.
No, it is not possible to contract the typical STDs, such as syphilis, gonorrhea, chlamydia, hepatitis B, etc. from wearing someone else's dirty underwear. However crabs and scabies, may be spread in this fashion.
Confidence votes 96.5K. Unless the Amish have doctrines that determine this, which is unlikely, some Amish women may wear underwear to bed and some may not. It's likely that they wear pajamas to bed and wearing underwear to bed is a personal choice.