in my medical school there was little to know about them as they usually do not cause "a disease". We did learn about hook worms and had to know if traveled outside of the US that we might have to learn about some others. But fot the most part they were just briefly covered at best. and then quickly forgotten. Maybe Doctors that went into infectous disease learned more laster in their training than I did, but other than trichomonous, Ob/Gym's did not deal with them much in a clinical situation.
The lack of health overall because of them or the cravings they caused , or any other microorganisms were not covered, if they were even know to "conventional medicine".