The virus in the episode is a fictional strain called an immuno pulmonary virus. This is similar to the Hantavirus. Hantavirus pulmonary syndrome (HPS) has been recognized as a disease only recently in North America. It is fairly uncommon and the chances of becoming infected are low even though it is potentially deadly. Hantaviruses that cause HPS are carried by rodents, especially the deer mouse. You can become infected by exposure to their droppings, and the first signs of sickness (especially fever and muscle aches) appear 1 to 5 weeks later, followed by shortness of breath and coughing. The disease then progresses rapidly, necessitating hospitalization and often ventilation within 24 hours. Prevention is the best strategy, and it simply means taking some very practical steps to minimize your contact with rodents. HPS is not contagious from person to person in the United States.

There are viruses that have been labeled as possible bioterrorist threats. The United States Centers for Disease Control and Prevention (CDC) has identified certain viruses as high-priority agents for bioterrorism because they include organisms that pose a risk to national security. These diseases that are named "Category A," high priority biological diseases, are Anthrax, Smallpox, Botulism, Tularemia, Viral Hemorrhagic Fever and Plague.