African traditional medicine is a form of holistic health care system organized into three levels of specialty, namely divination, spiritualism, and herbalism. The traditional healer provides health care services based on culture, religious background, knowledge, attitudes, and beliefs that are prevalent in his community.
I think that the italicized word is "trained" as it's a participle and there is no other participle or gerund! A participle is a verb form that can be used to modify a noun.
