The Technocyte Virus (or known as T-Cyte for short) is a dangerous infection featured in the game. It is still mostly enigmatic and its origins are not fully known, although it is hinted that the virus originated from the United States and that Yargo Mensik had a part in its creation. In the beginning of the game, a submarine is shown arriving in Lasria, with the infection on board. The same submarine is seen in the cutscene before Hayden Tenno's fight with Robert Mezner, and it is revealed to be of American origins.
It is said that sometime after Hayden's adventure in Lasria, the virus killed most of Earth's life in an incident known as "The Great Plague".
The most common means of contracting the disease is by directly absorbing it into the bloodstream. Most of those who are currently infected were in turn bitten, scratched or in some way injured by another of the infested. This has quickly caused the disease to spread like a plague through Lasria.
At first it was believed that the disease was also airborne, as suggested by the widespread use of hazmat suits. However, the neglect of these suits by some (especially those of higher rank), suggests that that the hazmat suits are purely used to make the soldiers "feel safer" even though they aren't. Dixon also explicitly states that the disease is not airborne and later arrives without wearing a gas mask or hazmat suit, giving more credence to his claim. However, the soldiers accompanying him wear advanced hazmat suits.
The first symptom to result from being infected is a metallic crust (usually with glowing dots) that forms on the skin. In and of itself, this would not be a problem; however, this transformation is extremely painful, so much so that most of those infected eventually lose their sanity. Mezner is the only known exception to this rule, as Hayden suffers no psychological effects due to his congenital analgesia.
Another symptom is an allergy to Enferon. When inhaled by one of the infected, it induces disorientation and eventually death in all of those suffering from the disease.
As of yet there is no known cure for the disease. Although the Agency provides boosters to its agents, these are actually placebos laced with Enferon, signifying that infected agents are just expected to die and disappear. Hayden almost kills himself by injecting himself with a booster, in an attempt to break Mezner's mental hold on him. He survives because Yargo flushes most of the Enferon out of Hayden's system. It has been speculated by players that the booster prevented further evolutions, but this is merely conjecture.
- The Technocyte Virus has a number of similarities to the real life rabies virus.
- The infected are often referred to as "zombies" because of their similarities.
- The virus appears in a later game developed by Digital Extremes "Warframe", although taking on different characteristics such as animalistic behavior and modification of the victim's molecular structure.
- The Technocyte Virus has a strong similarity with the Blacklight Virus from the Prototype franchise. Both viruses have caused viral outbreaks (with Technoctye's case: The Great Plague) and changes humans into zombies/infecteds, both enhances the physical abilities of the main protagonists, Technocyte makes metallic crust on the victim while Blacklight allows the user changing their limbs into deadly metallic weapons.
- The official strategy guide includes a report claiming that the virus is similar to the one seen in Raccoon City.
- This can be assumed to have been nothing more than a reference as the two pathogens are wildly different from each other.