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.
How We Know Lyme Disease is Sexually Transmitted. The Lyme infection, borrelia, can be sexually transmitted. However we do not know the actual rate or chance of transmission. There is limited science around this topic, but here it is. Studies do show borellia in vaginal fluid and male ejaculate of those who have positive testing with Lyme disease (1, 2).