According to the April 27, 2010 “China News” report: the two decisions of the State Council amended the provisions of Article 99 of the “Rules for the Implementation of the Law of the People’s Republic of China on the Health and Quarantine of the State Border” and Article 7(4) of the “Rules for the Implementation of the Law of the People’s Republic of China on the Administration of the Entry and Exit of Foreigners” respectively, the substance of the two decisions is the same, that is, the abolition of restrictions on the entry of foreigners suffering from AIDS, venereal disease, leprosy The two decisions are consistent in substance, i.e. the removal of restrictions on the entry of foreigners suffering from AIDS, sexually transmitted diseases and leprosy. Following this news report, some people showed psychological emotions of concern and anxiety about social health and safety. In fact, there are 110 countries and regions that do not restrict the entry of foreigners with AIDS. Professional studies have proven that daily contact does not lead to the spread of AIDS, STDs and leprosy. However, AIDS, STD and leprosy are infectious diseases, and AIDS is a high-risk disease. How to prevent AIDS? In addition to having a sufficiently good supporting management measures, it is also very important for the public to understand the etiology, pathology, transmission routes and clinical manifestations of AIDS. AIDS is an acquired immunodeficiency syndrome (AIDS), a sexually transmitted disease caused by human immunodeficiency virus (HIV), with severe immunodeficiency as the basic pathology and Pneumocystis carinii pneumonia, Kaposi’s sarcoma, chronic lymph node enlargement, non-Hodgkin’s lymphoma, and various conditional pathogenic infections as the main clinical manifestations. AIDS has been called a “super cancer”. Some scholars say that the AIDS epidemic is the fourth major infectious disease catastrophe in human history. We would like to introduce some knowledge about AIDS and hope that it will help to prevent AIDS. HIV is a single-stranded RNA virus, which is a retrovirus with an outer shell and an envelope outside the shell. HIV is intolerant of high temperature and loses its activity after 30 minutes of heating at 56°C. It is not easy to survive when it leaves the body; general disinfectants can inactivate it rapidly. HIV has obvious T-lymphocytic and neurophilic properties, contains special reverse transcriptase, and is a carcinogenic virus to humans. Sources of infection: The sources of HIV infection are people living with AIDS, people with AIDS-related syndromes, and people with asymptomatic HIV infection. HIV has been isolated from the blood, semen, saliva, tears, breast milk, urine and vaginal secretions of these three groups of people, with semen containing the highest levels of HIV, followed by blood and blood products. Those who have HIV infection without any abnormal manifestations and can live a normal life have a greater risk. Transmission routes: 1) close sexual contact with HIV-infected persons; 2) contact with or receipt of HIV-contaminated blood or blood products; 3) mother-to-child HIV transmission; 4) use of HIV-contaminated and unsterilized syringes, needles, razors, toothbrushes, etc.; 5) receipt of organs, tissues and semen from HIV-infected persons. Pathogenesis: HIV invasion of lymphocytes; HIV replication; immune deficiency; development of conditional infection. Severe immune deficiency occurs, making the organism vulnerable to infection by various pathogens. Clinical stages and manifestations: AIDS is divided into three clinical stages from the appearance of clinical symptoms: HIV infection stage, AIDS-related syndrome stage and AIDS stage. The clinical manifestations of AIDS have no characteristic manifestations, but are mainly manifestations of impaired immune function, such as delayed allergic response, fever of 38°C or more for three months, swelling of two or more non-inguinal lymph nodes for five months, and fatigue. At present, there is no practical treatment for AIDS, and most patients have a survival period of less than five years; therefore, the prevention of AIDS should be given great attention.