A fungal disease, with unknown mode of transfer from being from one animal to another, from man to man, or from other environment to animal or man. No consistent source has been found outside of animals or man, and because the organisms are more frequently found in the mouth of man and animals, the source of infection is believed to be endogenous. The transfer in this case must be by contact with carriers of the organisms and with fomites. Infected individuals no doubt also act as passive carriers at least.
Actinomycosis probably occurs in most parts of the world, although complete data are not available.