Two Pathogen-Based Etiological Theories of Infectious Diseases in Ancient Chinese Medicine: A Historical Review

In studies of the etiology of ancient Chinese medicine, the Qi-based theory of infectious diseases is mainly grounded in climatic explanations and has long been familiar to both scholars and the general public. With the gradual deepening of research on medical traditions such as folk medicine and religious medicine in ancient China, the worm-centered theory of infectious diseases, which focuses on biological pathogens, has become increasingly prominent. Representative of this framework are the doctrines of Gu and the Jiuchong (Nine Worms). These doctrines attribute the onset and transmission of many infectious diseases to the invasion and movement of real or hypothetical pathogenic Chong (worms). Corresponding methods were proposed to treat patients and halt disease transmission, including medicinal therapy, physical isolation, personal cultivation, and even religious rituals. Research on these theories helps to comprehensively understand how infectious diseases were perceived and managed in ancient China.