Are any parasitic diseases directly communicable from person to person? if so, how are they transmitted? what kinds of precautions should be taken in caring for persons with directly transmissible parasitic infections?

Yes they can. The simplest example would be Malaria which is actually a rather easily transmissible parasitic disease. You can transmit it by exchanging blood with someone who has malaria, or you get their organs. The best way to prevent this is to take medicine since there's not an actual cure or a vaccine for it, but there is medicine that helps you live with it.

Well, l think that some effective communication is, emotional barriers and lack of attention, interest distraction or irrelevance. also some physical disabilities such as hearing problems or speech difficulties.      l hope i am correct  and you good luck.