What is AIDS?

Aids, that is, acquired immunodeficiency syndrome (also translated as acquired immunodeficiency syndrome), is a transliteration of the English abbreviation AIDS. 198 1 The first injection in the United States was confirmed. It is translated into "AIDS" and "Love to death". There are two kinds: HIV- 1 and HIV-2, which are infectious diseases caused by injecting human immunodeficiency virus (also known as HIV). AIDS is called "the plague of the century", also known as "super cancer" and "the killer of the century".

Basic overview

AIDS is a zoonotic disease, which is caused by HIV infection. HIV is a virus that can attack the human immune system. It targets T4 lymphoid tissue, which is the most important tissue in human immune system, and destroys T4 lymphoid tissue in large quantities, leading to highly fatal internal failure. This virus is life-long infectious in this area, which destroys people's immune balance and makes the human body a carrier of various diseases. HIV itself will not cause any diseases, but when the immune system is destroyed by HIV, the human body loses the opportunity to replicate immune cells because of its low resistance, and is infected by other diseases, leading to various compound infections and deaths. The average incubation period of HIV in human body is 9 years to 10 years. Before they develop into AIDS patients, patients look normal. They can live and work for many years without any symptoms. The initial symptoms of AIDS infection

source and course

Scientific research found that AIDS was first spread in West Africa. A charity organization made a batch of vaccines for an epidemic and donated them to a country in Africa, but they didn't know that the chimpanzees used for vaccines carried HIV. An international research team composed of scientists from the United States, Europe and Cameroon said that they confirmed through field investigation and genetic analysis that human HIV- 1 originated from wild chimpanzees, and the virus probably evolved from simian immunodeficiency virus SIV. In fact, the origin of AIDS should be in Africa. 1959 Congo is still a French colony. An aborigine who came out of the forest was invited to participate in a research related to blood infectious diseases. After his blood sample was tested, it was refrigerated and dusty for decades. Unexpectedly, decades later, this blood sample turned out to be an important clue to solve the source of AIDS. 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 AIDS has been discovered in China (see Ceng Yi: AIDS epidemic trend, research progress and containment strategies). [1] AIDS is a serious threat to human survival, which has attracted great attention from the World Health Organization and governments around the world. Aids is spreading faster and faster around the world, seriously threatening human health and social development, and has become the fourth killer threatening human health. UNAIDS announced on May 30th, 2006 that since the first diagnosis of AIDS in June, 65 million people around the world have been infected with HIV in 25 years, of which 2.5 million have died. By the end of 2005, there were 38.6 million HIV-infected people in the world, with 465,438+million new HIV-infected people in that year, and another 2.8 million people died of AIDS. On Tuesday, July 29th, 2008, UNAIDS released the AIDS epidemic report in 2008. The report pointed out that in 2007, the global AIDS prevention and control work made remarkable progress, the AIDS epidemic showed a remission trend for the first time, and the number of new HIV-infected people and AIDS-related deaths decreased; However, the situation in different countries is not balanced, and the total number of AIDS patients in the world remains high. In 2007, there were 2.7 million new HIV-infected people in the world, 300,000 fewer than 200 1. The number of people who died of AIDS was 2 million, 200,000 less than 200 1. 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 kind of "super cancer" with a mortality rate almost as high as 100% has been listed as a Class B legal infectious disease in China, and it is one of the infectious diseases monitored by frontier health. Therefore, we call it "super terminal disease". Microscopic photos of HIV

The difference between HIV and AIDS

HIV stands for human immunodeficiency virus. After a person is infected with HIV, the virus begins to attack the human immune system. One function of the human immune system is HIV and human cells.

Repel the disease. In a few years, HIV will weaken the immune system. At this time, people will be infected with opportunistic infections, such as pneumonia, meningitis and tuberculosis. Once an opportunistic infection occurs, this person is considered to have AIDS. AIDS stands for acquired immunodeficiency syndrome. AIDS itself is not a disease, but a state or comprehensive symptom that cannot resist other diseases. People will not die from AIDS, but from AIDS-related diseases.

Edit this symptom

clinical picture

The clinical symptoms of AIDS are varied, such as common cold, flu, general fatigue, loss of appetite, fever, weight loss and so on. With the aggravation of the disease, the symptoms are increasing day by day, such as candida albicans infection, sticky skin, herpes simplex, herpes zoster, purpura, hematoma, blood blister, ecchymosis, easy skin injury, bleeding after injury and so on. In the future, it will gradually invade the internal organs and continue to have fever for unknown reasons, which can last for 3-4 months; Cough, shortness of breath, persistent diarrhea, bloody stool, hepatosplenomegaly, malignant tumor, dyspnea, etc. Because the symptoms are complex and changeable, not every patient has the above symptoms. There are usually more than one or two symptoms. According to damaged organs, dyspnea, chest pain, cough, etc. Often occurs when the lung is invaded; If it invades the gastrointestinal tract, it can cause persistent diarrhea, abdominal pain, emaciation and weakness. For example, thrombotic endocarditis and thrombocytopenic cerebral hemorrhage caused by invasion of blood vessels are 1. The general symptoms are persistent fever, weakness, night sweats and superficial lymphadenopathy. Within three months, the weight can be reduced by more than 10%, and the maximum weight can be reduced by 40%. The patient's emaciation is particularly obvious. Common symptoms of AIDS

2. Respiratory symptoms include long-term cough, chest pain, dyspnea, and blood in sputum in severe cases. 3. Symptoms of digestive tract include anorexia, anorexia, nausea, vomiting, diarrhea, and bloody stool in severe cases. Drugs commonly used to treat digestive tract infections are ineffective against this kind of diarrhea. 4. Symptoms of nervous system include dizziness, headache, slow response, mental retardation, mental abnormality, convulsion, hemiplegia and dementia. 5. The skin and mucous membrane damage diffuse papules, herpes zoster, oral and pharyngeal mucosal inflammation and ulcers. 6. There are many malignant tumors in the tumor. Kaposi sarcoma located on the body surface can be seen with red or purple spots, papules and invasive masses.

Clinical symptom characteristics

1. The incidence rate is mostly in young adults, and 80% of the onset age is 18-45 years old, which is the age when sexual life is more active. 2. People infected with AIDS often suffer from some rare diseases, such as pneumocystis pneumonia, toxoplasmosis, atypical mycobacteria and fungal infection. 3. Persistent and extensive systemic lymphadenopathy. Especially in the neck, armpit and groin, the lymphadenopathy is more obvious. The diameter of lymph nodes is larger than 1 cm, and the texture is solid, movable and painless. 4. Complicated with malignant tumor. Kaposi's sarcoma, lymphoma and other malignant tumors. 5. Central nervous system symptoms. About 30% of AIDS cases have this symptom, such as headache, disturbance of consciousness, dementia, convulsions and so on. , often lead to serious consequences.

Four symptoms

There is a complete natural process from HIV infection to onset. Clinically, this process is divided into four stages: acute infection period, incubation period, pre-AIDS period and typical AIDS period. Not every infected person will have a complete four-stage performance, but patients at every disease stage can see it clinically. The different clinical manifestations in the four periods are a gradual and coherent development process. 1. The window period of acute infection is also at this time. After HIV attacks the human body, the body is stimulated and reacts. The patient developed fever, rash, swollen lymph nodes, fatigue, sweating, nausea, vomiting, diarrhea and pharyngitis. Some people also suffer from acute aseptic meningitis, which is characterized by headache, neurological symptoms and meningeal irritation. Peripheral blood tests showed that the total number of white blood cells was normal, or lymphocytes decreased and monocytes increased. In acute infection, the symptoms are often mild and easy to be ignored. When this fever and other general malaise symptoms appear after about 5 weeks, the serum HIV antibody can show a positive reaction. Since then, a relatively healthy and asymptomatic incubation period has appeared in clinic. Acute infection symptoms

2. Infected people in the incubation period may not have any clinical symptoms, but the incubation period is not static, let alone safe, and the virus continues to multiply, which has a strong destructive effect. The incubation period refers to the time from HIV infection to the appearance of clinical symptoms and signs of AIDS. It is now considered that the average incubation period of AIDS is 2- 10 years. This has caused great difficulties for early detection and prevention of patients. 3. AIDS-related symptoms and signs began to appear after the pre-AIDS incubation period until it developed into a typical AIDS. There are many names during this period, including AIDS-related syndrome, lymphadenopathy-related syndrome, persistent systemic lymphadenopathy and pre-AIDS syndrome. At this time, the patient has the most basic feature of AIDS, that is, cellular immune deficiency, but the symptoms are mild. The main clinical manifestations are as follows: A. Lymph node enlargement is one of the most important clinical manifestations at this stage. Mainly superficial lymphadenopathy. The most common parts are head and neck, armpit, groin, back of neck, front of ear, back of ear, femoral lymph nodes, submandibular lymph nodes and so on. Generally, there are at least two or more parts, some as many as a dozen. Enlarged lymph nodes do not respond to general treatment, and often last for more than half a year. About 30% patients only have superficial lymphadenopathy clinically, and there are no other systemic symptoms. B. Patients with systemic symptoms often have symptoms such as general malaise and muscle pain caused by viral diseases. About 50% patients have fatigue and periodic low fever, which often lasts for several months. Night sweats,/kloc-0 more than 5 times a month. About 65,438+0/3 patients lost more than 65,438+00% weight. This weight loss cannot be explained by fever alone, nor can it be controlled by supplementing enough calories. Some patients have headache, depression or anxiety, some have sensory nerve endings, which may be related to the virus invading the nervous system, and some may have reactive mental disorders. 3/4 patients may have splenomegaly. C. Various infections During this period, in addition to the above superficial lymphadenopathy and systemic symptoms, patients often have various special or recurrent non-fatal infections. Repeated infection will accelerate the development of the disease and make the disease enter a typical AIDS period. About half of patients have severe tinea pedis, usually unilateral, and lack effective response to local treatment. Patients often suffer from staphylococcus infection and bullous abscess in armpit and groin, and patients often suffer from condyloma acuminatum and verruca vulgaris virus infection in perianal region, genitals, weight-bearing parts and oral mucosa. The incidence of herpes simplex and herpes zoster in the mouth and lips is also significantly higher than that in the normal population. Oral Candida albicans is also quite common, mainly manifested as oral mucosal erosion, congestion and cheese-like coverage. Other common infections are non-streptococcal pharyngitis, acute and chronic sinusitis and intestinal parasitic infection. Many patients defecate more frequently and become thinner and more sticky. It may be related to proctitis and the invasion of intestinal tract by various pathogenic microorganisms. In addition, hairy leukoplakia can appear in the oral cavity, and the existence of hairy leukoplakia is an important clue for early diagnosis of AIDS. The typical AIDS period is called fatal AIDS by some scholars, and it is the last stage of HIV infection. This period has three basic characteristics: severe cellular immune deficiency. All kinds of fatal opportunistic infections will occur. Pictures of severe AIDS.

All kinds of malignant tumors occur. At the end of AIDS, the immune function completely collapsed, and patients developed various serious comprehensive diseases until they died. The diagnosis of AIDS can not only rely on clinical manifestations. The most important basis is whether the examiner's blood test is positive. Therefore, if you suspect that you are infected with HIV, you should go to the local health and quarantine department for inspection in time, and don't make a diagnosis yourself.

Edit this part of pathology.

characteristic

At room temperature, HIV in liquid environment can survive 15 days, and articles contaminated by a large number of HIV are contagious within 3 days under humid conditions. In recent years, some research institutions have proved that the survival time of HIV virus in separated blood depends on the virus content in the separated blood. Blood with high virus content is still alive even if it is stored at room temperature for 96 hours. Even a drop of blood the size of a needle tip, if it meets fresh lymphocytes, HIV can still replicate and spread in it. Blood with low virus content loses vitality after natural drying for 2 hours; Blood with high virus content, even if dried for 2-4 hours, can still enter lymphocytes and continue to replicate once it is put into the culture medium (which does not exist in real life). Therefore, isolated blood containing HIV can cause infection. However, HIV is very fragile and can be inactivated when heated to 56 degrees 10 minute. If boiled, it can be quickly inactivated; When the temperature is 37℃, treat with 70% alcohol, 10% bleaching powder, 2% glutaraldehyde, 4% formalin, 35% isopropanol, 0.5% lysol and 0.3% hydrogen peroxide for 0/0 min to inactivate HIV. Although HIV can be seen everywhere, these viruses also have weaknesses. They can only survive in living cells in blood and body fluids, but not in air, water and food. Without these blood and body fluids, these viruses will soon die. Only when the blood or body fluid with the virus directly enters another person's body can it spread. Like hepatitis B virus, it will be destroyed by protease in the digestive tract after entering it. Therefore, daily contact, such as shaking hands, kissing, eating, sharing a room or office, touching the phone, door handle, toilet, sweat or tears, will not be infected with AIDS.

virus infection

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. This period is called incubation period, and incubation period is asymptomatic infection period. During this period, there were no conscious symptoms and positive signs except HIV antibody. The incubation period ranges from half a year to 12 years, and a few can reach more than 20 years. The average incubation period of HIV in human body is 6 years. Opportunistic infection: 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 that 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. The red ribbon in Carinthia's lungs is an international symbol, indicating the fight against AIDS.

Cysticercosis 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 swollen lymph nodes 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 sections 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 cellulose. (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. Viral (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 often manifests as hepatitis, cytomegalovirus pneumonia, cytomegalovirus retinitis, thrombocytopenia and leukopenia.

, rash, etc. 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. 3. Fungal (1) Candida albicans infection: Candida albicans is a conditionally pathogenic fungus, which often exists in normal people's skin, mouth, upper respiratory tract, intestine and vaginal mucosa, and can be cultured from skin and mucosal secretions, urine and sputum. When the human body's resistance drops or the flora in the body is out of balance, Candida albicans can become a pathogenic bacteria, causing candida infection. It can be divided into cutaneous candidiasis and mucosal candidiasis. The latter is more common as thrush-the milky white film on the oral mucosa, glossopharyngeal mucosa, gums or lips, which is easy to peel off, revealing a fresh and moist ruddy base. More common in the late stage of serious diseases, or HIV-infected people. If homosexuals continue to have thrush without other explanations, it often indicates that patients have been infected with HIV or will develop into AIDS. Candidal esophagitis can cause dysphagia and pain or retrosternal pain. Esophagoscopy showed irregular ulcer and white false membrane in esophageal mucosa. Others include meningococcal keratitis, candidal vaginitis, candidal balanitis and visceral candidiasis. The diagnosis of candidiasis in skin and mucosa depends on clinical manifestations and fungal examination. (2) Cryptococcosis is an acute or chronic deep fungal disease caused by Cryptococcus neoformans infection. When the human body's resistance is weakened, it is easy to invade through the respiratory tract and occasionally through the intestine or skin. Cryptococcal meningitis is a common complication of AIDS. The mortality rate is very high, which is characterized by fever, headache, insanity and meningeal irritation. Cryptococcus pulmonalis, subacute or chronic onset, accompanied by cough, excessive phlegm, low fever, chest pain, fatigue and nonspecific changes in X-ray examination. The diagnosis of cryptococcosis is mainly based on clinical manifestations and fungal examination. 4. Bacteria (1) Mycobacterium tuberculosis: Mycobacterium tuberculosis often occurs in patients who have been infected with AIDS but have not yet been infected with AIDS. This may be because Mycobacterium tuberculosis is more virulent than other AIDS-related pathogens, such as Pneumocystis carinii, so tuberculosis is more likely to occur in the early stage of immunodeficiency. 74% ~ 100% of AIDS patients with pulmonary tuberculosis suffer from pulmonary tuberculosis, and its symptoms and signs are often difficult to distinguish from other AIDS-related pulmonary diseases. Aids patients often show diffuse infection. The most prominent clinical feature of AIDS patients complicated with tuberculosis is the high incidence of extrapulmonary tuberculosis. More than 70% of AIDS tuberculosis patients or patients diagnosed with tuberculosis have extrapulmonary tuberculosis. The most common forms of AIDS complicated with extrapulmonary tuberculosis are lymphadenitis and miliary lesions, which usually affect bone marrow, genitourinary tract and central nervous system. (2) Atypical mycobacterial infection: It is one of the important complications of AIDS, often involving liver, lung, spleen, kidney, blood, bone marrow, gastrointestinal tract and lymph nodes. Its manifestations are fever, emaciation, malabsorption, lymphadenopathy and hepatosplenomegaly. Laboratory examination is nonspecific, and diagnosis depends on pathogen isolation, culture and biopsy. (3) Other common pathogens: Pseudomonas aeruginosa, Escherichia coli, typhoid Bacillus and Neisseria gonorrhoeae. Can lead to opportunistic infections.