Abstract
Endogenous infection was first proposed by Escherlich in 1589 as infection induced by a normal flora, which exists in the body. One case of herpes zoster in the face simulta-neously associated with pulmonary tuberculosis was observed, and its mechanism of occur-rence has been under investigation sionce then. Finally, a new general broad interpre-tation of endogenous infection has been developed. Endogenous infection falls into two categories. The first is infection caused by normal flora, which originally exists in the body. The second is infection caused by latent pathogens which have invaded into the body at a previous infection, whose occurrence depends on the host's condition. The lat-ter type includes herpes zoster and endogenous activation tuberculosis. The causes of endogenous infection exist mainly in the hosts. Therefore, investigation of the causes of endogenous infection requireshostology.
