The "cryptohantavirus" was made up, but there are hanta viruses, monitored by the CDC, that are transmitted by rodents and cause pulmonary death.
Red-haired actress: Amy Price-Francis.
The "Zitek" building in this episode was also used in an episode of the X-Files in 2000 as the "FPS headquarters"; season 7 episode 13. The word "Zitek" is added to the front of the building and the first two numbers (2 and 5) of the address removed from the building leaving just a 3 and a 4.