What is AIDS?
AIDS is the Chinese name of English "AIDS", and AIDS is the English abbreviation of acquired immunodeficiency syndrome. It is a fatal infectious disease caused by human immunodeficiency virus (HIV). Aids virus mainly destroys the immune system of human body, making the body gradually lose its defense ability and unable to resist various external pathogens, so it is easy to infect infectious diseases and tumors that ordinary healthy people are not easy to suffer, and eventually lead to death. A person infected with HIV may feel good about himself for a long time, but they can spread the virus to others. It has been less than 20 years since AIDS was discovered, but its worldwide prevalence has infected more than 30 million people and killed more than 30 million people. At present, more than 1 10,000 people are newly infected with AIDS every day in the world. Not only the medical profession is doing its best to study the prevention and treatment of AIDS, but also the government and all walks of life are committed to the campaign to prevent and treat AIDS. But so far, we humans have not found a cure for this disease. Therefore, everyone should pay attention to AIDS for their own health and family happiness. Understand AIDS, and then prevent AIDS.
What is HIV?
The medical name of HIV is "human immunodeficiency virus" (abbreviated as HIV). After it invades the human body, it destroys the immune system, causes many incurable infections and tumors in the human body, and eventually leads to death.
What are the differences between HIV-infected people and AIDS patients?
HIV-infected persons refer to those who have been infected with HIV, but have not shown obvious clinical symptoms and have not been diagnosed with AIDS; Aids patients refer to people who have been infected with HIV and have obvious clinical symptoms and are diagnosed with AIDS. The similarity between the two is that they both carry HIV and are contagious. The difference is that AIDS patients have obvious clinical symptoms, while HIV-infected people have no obvious clinical symptoms and look like healthy people. It may take several years to 10 or even longer to develop from an HIV infected person to an AIDS patient.
Why is AIDS a "super terminal disease"
The full name of AIDS is acquired immunodeficiency syndrome (AIDS), which is transmitted through sex, blood and mother-to-child contact. It is an infectious disease that seriously harms health. When the human body is in a normal state, the immune system in the body can effectively resist various virus attacks. Once HIV invades the human body, this good defense system will collapse, and various viruses will take the opportunity to take blood and broken wounds. In addition, some abnormal cells in the human body, such as cancer cells, will also grow and multiply rapidly and eventually develop into various cancers. Generally speaking, HIV is a fatal blow to people by destroying their immune system and physical resistance.
AIDS originated in Africa and was brought to the United States by immigrants. On June 5th, 198 1, the Center for Disease Control in Atlanta, USA briefly introduced the medical history of five AIDS patients in Morbidity and Mortality Weekly, which was the first official record of AIDS in the world. In 1982, this disease is named "AIDS". Soon after, AIDS quickly spread to all continents. 1985, a young foreigner who traveled to China fell ill and died soon after being admitted to Peking Union Medical College Hospital, and was later confirmed to have died of AIDS. This is the first time that China has discovered AIDS.
Aids is a serious threat to the survival of mankind, which has attracted great attention from the World Health Organization and governments all over the world, and the investment in personnel and funds is amazing. According to statistics, nearly 40 million people around the world are infected with HIV, and thousands of people have died here. According to experts, it takes several years, even as long as 10 or even longer, for HIV-infected people to develop into AIDS patients from the initial stage of infection. Aids patients will have a variety of infections due to extremely low resistance, such as herpes zoster, oral mold infection, tuberculosis, enteritis, pneumonia, encephalitis caused by special pathogenic microorganisms and so on. Malignant tumors often occur in the later stage until they die of long-term consumption and general failure.
Although many medical researchers around the world have made great efforts, so far, no specific drugs have been developed to eradicate AIDS, and there is no effective preventive vaccine. At present, this "super cancer" with a mortality rate of almost 100% has been classified as a Class B legal infectious disease in China, and it is one of the infectious diseases monitored by frontier health, so we call it "super terminal disease".
The pathogen of AIDS
Aids is acquired immunodeficiency syndrome (AIDS). This is a chronic and fatal infectious disease, which is caused by human immunodeficiency virus (HIV). HIV infection leads to a series of clinical syndromes such as human immunodeficiency and opportunistic infection, and the mortality rate is almost 100%. HIV belongs to retrovirus family, lentivirus genus and primate immunodeficiency subgenus. It has been confirmed that HIV can be divided into two types: HIV- 1 and HIV-2, both of which have their own subtypes. Different subtypes are prevalent in different regions, and the same subtype has certain differences in different regions.
Pathogenesis of AIDS
HIV virus is a cytotoxic virus, which mainly proliferates in' helper T lymphocytes' to destroy cells. And' helper T lymphocytes' are extremely important immune cells in human body, and their destruction will gradually lead to immune failure. In this way, even an infection that is insignificant to normal people, such as a small wound or a common cold, can kill AIDS patients.
Clinical manifestations of opportunistic infection of AIDS
The so-called opportunistic infection, that is, conditional pathogenic factors, refers to some microorganisms with low invasiveness and weak pathogenicity, which cannot cause disease when the human immune function is normal, but when the human immune function is reduced, it creates infection conditions for such microorganisms to attack the human body and cause disease, so it is called opportunistic infection. Autopsy results show that 90% of AIDS patients died of opportunistic infections. There are dozens of pathogens that can cause opportunistic infection of AIDS, and many pathogens are often mixed. It mainly includes protozoa, viruses, fungi and bacterial infections.
1. Protozoa
(1) Pneumocystis carinii pneumonia: Pneumocystis carinii is a small protozoa, which makes holes in human lungs. People can't see it with the naked eye, and they can't find it with ordinary biological culture methods. Pneumocystis carinii pneumonia is mainly transmitted through the respiratory tract through air and droplets. When healthy people are infected with HIV, their immune function is destroyed. At this time, Pneumocystis carinii will take advantage of the situation and multiply in patients, filling alveoli with exudate and various forms of Pneumocystis carinii, causing serious damage to the lungs. Pneumocystis carinii pneumonia was a rare infection before the AIDS epidemic. In the past, it was only found in infants during war and hunger, or in leukemia children receiving immunosuppressive treatment. Pneumocystis carinii pneumonia is a common cause of death among AIDS patients, which is the most serious opportunistic infection among more than 60% AIDS patients, and about 80% AIDS patients will have pneumocystis carinii pneumonia at least once. When AIDS patients are complicated with Pneumocystis carinii pneumonia, symptoms such as progressive malnutrition, fever, general malaise, weight loss and lymphadenopathy first appear. Cough, dyspnea, chest pain and other symptoms occurred later, and the course of disease was 4-6 weeks. Fever (89%) and shortness of breath (66%) are the most common symptoms of the lungs. Some people can still hear lung rales. Pneumocystis carinii pneumonia is a common cause of death in AIDS patients, which often occurs repeatedly and has a serious condition. Chest x-rays of pneumocystis carinii pneumonia show extensive infiltration of both lungs. However, a few patients (about 23%) can show normal or very few abnormalities on chest radiograph. According to the X-ray examination of 180 cases of pneumocystis carinii pneumonia, 77 cases showed bilateral interstitial pneumonia, 45 cases showed interstitial and alveolar inflammation, 26 cases showed interstitial inflammation around hilum, 24 cases showed unilateral alveolar and interstitial inflammation, and 8 cases were normal. Pulmonary function examination showed that the total lung volume and vital capacity decreased, and further aggravated with the progress of the disease. Pneumocystis carinii can be found in specimens taken by bronchoscopy or lung puncture, and sometimes other pathogens can be found. This is a mixed opportunistic infection. The course of disease is urgent; It can also be slow and eventually die of progressive dyspnea, hypoxia and respiratory failure, with a mortality rate of 90% ~ 100%.
(2) Toxoplasma gondii infection: Toxoplasma gondii infection in AIDS patients mainly causes toxoplasmosis in the nervous system, with an incidence rate of 26%. The clinical manifestations are hemiplegia, focal neurological abnormality, convulsion, disturbance of consciousness and fever. CT examination showed single or multiple lesions. Toxoplasma gondii can be seen according to histopathological section or cerebrospinal fluid examination. Very few toxoplasmosis involved the lungs (1%). The disease is an animal infectious disease caused by parasitic protozoa Toxoplasma gondii. The route of human infection, congenital infection is transmitted from mother to fetus through placenta. Acquired infection is caused by eating raw or undercooked meat containing cysticercosis.
(3) Cryptosporidiosis: Sarcocystis is a small protozoa parasitic on domestic animals and wild animals. People attach to the epithelium of small intestine and large intestine after infection, which mainly causes malabsorption diarrhea. The patient showed uncontrollable watery stool, losing 3- 10 liter of water every day, and the mortality rate could be as high as 50%. Diagnosis depends on colonoscopy biopsy or finding oocysts in feces.
2. Virus
(1) cytomegalovirus infection: According to serological investigation, cytomegalovirus is widespread, and most patients infected with cytomegalovirus are asymptomatic, but patients infected with cytomegalovirus can excrete virus in urine, saliva, feces, tears, milk and semen for a long time. It can be transmitted through blood transfusion, mother's placenta, organ transplantation, sexual intercourse and breastfeeding. When AIDS is accompanied by cytomegalovirus infection, it is often manifested as hepatitis, cytomegalovirus pneumonia, cytomegalovirus retinitis, thrombocytopenia, leukopenia and rash. In order to diagnose cytomegalovirus infection, inclusion bodies or isolated viruses must be found in biopsy or autopsy samples. According to Guarda's autopsy study on 13 AIDS patients, the most common diagnosis was cytomegalovirus infection (12 cases), followed by Kaposi's sarcoma (l0 cases). All 12 cases of cytomegalovirus infection are disseminated and often involve two or more organs.
(2) Herpes simplex virus infection: its transmission route is mainly direct contact and sexual contact, but also through droplets. Viruses can invade the human body from respiratory tract, mouth, eyes, genital mucosa or broken skin. Pregnant women may also pass it on to their babies during childbirth. Infection with the virus can cause skin and mucous membrane damage of AIDS patients, involving oral cavity, vulva, perianal region, back of hand or esophagus, bronchus and intestinal mucosa. Herpes simplex in the mouth and lips is the most common, and its damage is characterized by dense clusters of small blisters, which are slightly red at the base and can form ulcers after being scraped off. Ulcer is characterized by large, deep and painful, often accompanied by secondary infection, severe symptoms, long course of disease, and the damaged part can be cultured.
(3) Epstein-Barr virus: The infection rate of this virus in AIDS patients is very high. Epstein-Barr virus antibody can be detected in the serum of 96% AIDS patients. Epstein-Barr virus can cause primary mononucleosis, accompanied by hemolytic anemia, lymphadenopathy, systemic macula and T cell reduction.