Medical Pamphlet

Center for Disease Control

The Last of Us


The Center for Disease Control has produced this pamphlet on Cordyceps Brain Infection (CBI) to increase awareness and prevention of infection.


The Cordyceps mushroom is a parasitic fungi that can take over a host's mind and alter its behavior. Until recently it has only affected insects and some arthropods. A new species has emerged with the ability to target human hosts.


The two known ways to contract CBI are:

Breathing the spores emitted by the Cordyceps.

Contact with bodily fluids of a person infected with CBI, usually by being bitten.


After initial infection, the parasite travels to the host's brain over a period of one to two days.

The incubation concludes when the Cordyceps has taken over all major bodily functions of the host (Stage One CBI).


Stage One CBI patients display erratic and violent behavior, lashing out at anyone around them.

Eventually the fungus pushes through the host's tissue to allow for the release of airborne spores.


There is no vaccine for CBI, nor any known treatment to lengthen the incubation period.


CBI can be diagnosed using a blood or microscopic imaging test (usually administered against the ear). Within minutes of contraction, the results of this test will come out positive.