0 the first person in a group known to be suffering from a disease or medical condition that can be passed on to others, either through infection or in the genes:
Index patients and all available family members were invited for clinical examination.
The possibility of transmission from the index patient on these two flights cannot be excluded.
Four of seven children of the index patient's aunt (father's side) died suddenly at an early age.
The index patient had a twin brother who suffered from spina bifida and three other siblings with heart conditions.
Nose, throat and wound cultures were taken from staff and patients who had had contact with the index patient.
He was the index patient in a deadly outbreak at the hospital in the early 1990s.
