In dreams, the idea of being quarantined is the idea that others are prohibited from contact with you for generally secretive reasons. This is different from aloneness (which is voluntary) or abandonment (which is malicious). In quarantine it is often for your own good that others are leaving you alone. In these dreams it is the need to cleanse or renew the spirit that often creates this situation.
Another version of this dream is being quarantined for punitive reasons. If you are experiencing some ambivalence about your moral life, you may bring quarantine upon yourself in dreaming as a means of resolving the situation. You may be seeking a "clean bill of health" from others concerning the situation that has prompted the quarantine situation.
Basically, it is a way of testing taboos subconsciously. If your waking life has brought you to a place of moral uncertainty, your subconscious may govern a time of evaluation, while you dream of being separated from the person or circumstances central to the conflict.