50. For the prevention and control of infectious diseases, the "four early" measures refer to $\qquad$
A. early detection, early reporting, early isolation, early treatment B. early detection, early disinfection, early diagnosis, early treatment
C. early detection, early diagnosis, early reporting, early isolation D. early detection, early diagnosis, early disinfection, early isolation
【Answer】A
【Analysis】Early detection, early reporting, early isolation, and early treatment are the key measures to control the spread of infectious diseases, abbreviated as the “four early actions”. The spread of infectious diseases in the population must have three basic links: the source of infection, the transmission route, and the susceptible population. The absence of any one of these links will not lead to new infections and outbreaks. Preventive and control measures for infectious diseases can be divided into three categories: controlling the source of infection, cutting off the transmission route, and protecting the susceptible population. Adhering to the “four early actions”, ensuring early detection, early reporting, early isolation, and early treatment of patients and asymptomatic carriers, prevents a larger-scale outbreak and protects the health of a broader population; at the same time, through the “four early actions”, timely discovery and treatment of patients can be achieved, minimizing the damage of the epidemic to people's lives and health.

【Comment】“The best doctor treats the disease before it occurs,” preventing problems before they arise. The country implements a prevention-oriented policy for the prevention and control of infectious diseases, strengthening the learning of knowledge about the prevention and treatment of infectious diseases, enhancing self-protection awareness, and fostering a civilized and healthy lifestyle.