【重要】IntroductionofCommunicableDiseases.doc

《传染病学》双语教学讲义 INTRODUCTION OF COMMUNICABLE DISEASES 浙江大学医学院 传染病学教研室 阮 冰 整编  Introduction of Communicable Diseases RUAN Bing Communicable diseases are caused by various pathogens including microorganisms (e.g. prion, virus, chlamydia, rickettsia, bacteria, fungus, spirochete) and parasites (e.g. protozoa and helminth). They may be transmitted to others as infection and spread in the population as epidemic, therefore they are the diseases with high morbidity. Many of them may be prevented and effectively treated. In China, great change has taken in prevention and treatment of infectious diseases. Before 1949, many pestilences were rampant, such as plague, smallpox, malaria, schistosomiasis and kala-azar. After the founding of the Peoples Republic, we have carried out the principle of prevention first, launched with vast efforts the patriotic health campaigns, strengthened our work on infectious diseases prevention and building of health infrastructure. As a result, health situation in both town and country has taken on a new look, and people health has been improved greatly. Now many classical infectious diseases have been controlled and eradicated, such as smallpox, poliomyelitis, plague, cholera, and measles, but some infectious diseases are still popular, such as viral hepatitis, HFRS (hemorrhagic fever with renal syndrome), infectious diarrhea, and so on. Meanwhile, some re-emerging infectious diseases such as syphilis and tuberculosis are re-appeared, and emerging infectious diseases such as AIDS (acquired immunodeficiency syndrome), SARS (severe acute respiratory syndrome, namely infectious atypical pneumonia), and infections caused by resistant mutants are arisen. Section 1 Infection and immunity 1.1 Conception of infection Infection refers to interaction between pathogen and host. Under normal circumstances, human being lives in delicate dynamic balance with the microorganisms of internal and external environments. When this balance is upset, organisms may