"The Spirit of the Lord is on me, Because he has anointed me to preach good news to the poor. He has sent me to heal the brokenhearted, To proclaim release to the captives, Recovering of sight to the blind, To deliver those who are crushed,

 Here Luke the doctor writes. In the grip of a major fever--every word is a medical term. In the grip of is the medical Greek for someone definitely laid up with an illness. The Greek medical writers divided fevers into two classes--major and minor. Luke knew just how to describe this illness. 