Nowhere to run / Mary Jane Clark.

Enhanced descriptions from Syndetics:

A newsroom has nothing to hide . . . or does it?
A killer has everything to lose . . . but is it worth it?
A woman has no one to trust . . . so will she be next?
Botulism, anthrax, small pox, plague: as medical producer for television's highly-rated morning news program, "Key to America," Annabelle Murphy makes her living explaining horrific conditions to the nation. So when a KEY News colleague dies with symptoms terrifyingly similar to those of the latest scourge, she knows the panic spreading through the corridors of the Broadcast Center is justified. As one death follows another, Annabelle's co-workers look to her for assurance but she finds it hard to give comfort. To her, the circumstances of the infections begin to suggest that they may be diabolical murders. And when the authorities lock down the Broadcast Center with the identity of the killer still unknown, no one can be sure who to trust, and neither the victims nor the murderer can escape...
"Nowhere To Run" is full of Mary Jane Clark's signature intricate plotting and taut psychological suspense.