Quiet Killer (1992)

On her flight home to New York, teenage Sara becomes very ill. She realizes too late that it's more than a cold, and with her parents still on vacation, she breaks down in the middle of the street and dies shortly afterward in a hospital--of the plague, as the terrified coroners find out. While trying to keep this from the public to avoid a panic, epidemic commissioner Dr. Nora Hart must investigate Sara's identity and find everyone who had contact with her. If she misses a single person, the plague could kill half the city in a few days.