Lower respiratory tract infection poses a major threat to the population's health, which brings about severe health damage and disease burden, especially in infants and the elderly. The prevalence and pathogen spectrum of lower respiratory tract infections differ in countries and regions as influenced by various factors such as region, population, and pathogen detection methods. The prevalence and severity of this group of diseases are jointly affected by pathogens, host characteristics, and the external environment. Monitoring programs set for the local epidemic situation, pathogen spectrum, and influencing factors of lower respiratory tract infection helps develop comprehensive prevention and control strategies according to local conditions and allocate and utilize medical and health resources more reasonably.

Lower respiratory tract infection; Epidemiology; Disease burden; Pathogenic spectrum; Influencing factors