Problem:

Three days before a nurse developed meningococcemia, she assisted with intubation of a patient with a Neisseria meningitides infection. Of the 24 medical personnel involved, only this nurse became ill. The nurse recalled that she was exposed to nasopharyngeal secretions and did not receive antibiotic prophylaxis.

Required:

Question: What two mistakes did the nurse make? How is meningitis transmitted?

so any suggestions should ideally aid in this goal.