All of the zombies currently held in our research facility here in Florida were rounded up by a joint C.D.C./D.O.D. task force in the 1950s during the aftermath of an industrial accident in rural Pennsylvania,(the details of which remain classified).
At this time, 23 of the original 150 units remain in original "functioning" condition, while the rest have been neutralized for research purposes, or loaned to other institutions in the form of animate, but unassembled test subjects.
Our research and development department has been able to answer, and confirm three of the frequently asked questions about these alternatively animated beings :
1) The only way to neutralize one of these
subjects permanently, short of total
obliteration, is (as previously thought)
destruction, or removal of the brain.
2) The seemingly insatiable craving that
these subjects have for human brain
matter, is actually a craving for the
cerebrospinal fluid which is produced
in the ventricles of the brain, and
surrounds the brain and spinal cord.
For some reason, ingestion of CSF seems
to stabilize what little brain function
remains intact, such as motor function.
3) As previously feared, any healthy human
who is exposed to the saliva, or other
bodily secretions of one of these
subjects through open wounds,(including
those who are killed, and partially
eaten providing the brain is left
intact) will be infected, and soon
reanimated with all of the symptoms
noted is previous subjects.
Extensive security measures have been taken at our facility to ensure no further outbreaks such as the one in Pennsylvania occur. Since 1958, only three "zombies" have managed to escape our high security holding facility. One being destroyed by an alligator in the surrounding swamps, and the other two being captured in a nearby town by our rapid response team, with minimal civilian casualties.