The extreme advantages conferred upon those infected by this virus suggest that it has been present in humans for hundreds, perhaps thousands, of years. An analysis of historical case studies provides further support for this claim by confirming that the strain has mutated over many generations, developing resistance to substances which may have once slowed or killed it.
Once in the brain, the virus resembles rabies* in that it is programmed to infect the brain centers that induce aggression and the urge to bite others. Simultaneously it infects the salivary glands, where it may be transmitted to others through bites. For these reasons, the name "Sanguinofamia Mordens" or SFM is suggested.
Symbiotic enhancement of the host promotes transmission of the virus in the following ways:
1) Physical - Damage to NMDA receptors disrupts a number of neurotransmitter systems, which includes the disinhibition of dopamine release. Similar to PCP, this produces anesthesia to pain (which promotes a feeling of immortality) as well as mental stimulation (which provides an abnormal awareness of sensations, including sight, smell and sound) This damage increases the subject's physical prowess, and thus his ability to successfully transmit the virus in an attack.
2) Psychological - Damage to ventral frontal lobes results in an emotion-processing disorder in which the subject shows reduced ability to respond to emotional signals derived from faces and voices in social interactions. Subjects are therefore less affected by the emotional responses of their victims, and thus more likely to be able to transmit the virus through an attack.
VS. CARRIER STATES
The key difference between the development of the carrier state (vs. the chronic) appears to be that the subject has retained enough of his own blood to both fight the infection with white blood cells, and manufacture enough healthy hemoglobin to sustain physiological functioning. With the immune system reducing the viral load, the psychological effects such as the urge to bite are reduced; while the limited production of healthy hemoglobin reduces the constant need for fresh blood. However, it is important to note that although reduced, no symptom is entirely absent in the carrier state.
Responsible for this research is Jessica, who receives funding from an unknown source to continue her research and formulate a cure for the virus.
* Taken from the Wikipedia excerpt on vampires:
Rabies has been linked with vampire folklore. Dr Juan Gómez-Alonso, a neurologist at Xeral Hospital in Vigo, Spain, examined this possibility in a report in Neurology. The susceptibility to garlic and light could be due to hypersensitivity, which is a symptom of rabies. The disease can also affect portions of the brain that could lead to disturbance of normal sleep patterns (thus becoming nocturnal) and hypersexuality. Legend once said a man was not rabid if he could look at his own reflection (an allusion to the legend that vampires have no reflection). Wolves and bats, which are often associated with vampires, can be carriers of rabies. The disease can also lead to a drive to bite others and to a bloody frothing at the mouth.