1. Clinically, it is divided into four stages, showing a gradual and coherent development process.
1). Acute infection period: After being infected with HIV, HIV stimulates the body to cause immune response. After that, it entered a relatively healthy asymptomatic infection period with different lengths.
Clinical symptoms: Some patients have transient infectious mononucleosis-like symptoms. Sudden onset, fever, sweating, headache, sore throat, nausea, anorexia, general malaise, joint muscle pain and other symptoms. At the same time, it may be accompanied by erythema, vomiting, diarrhea, systemic lymphadenopathy or thrombocytopenia. Some people also suffer from acute aseptic meningitis, which is characterized by headache, nervous system symptoms and meningeal irritation.
Peripheral blood test: the total number of white blood cells is normal, or lymphocytes decrease and monocytes increase. The proportion of CD4/CD8 cells in lymphocyte subsets cannot change significantly. This period lasts for a week or two. Because the symptoms in this period are not characteristic and mild, they are often misdiagnosed as colds and ignored. After 2 ~ 6 weeks of infection, the serum HIV antibody can be positive.
2). Asymptomatic infection period: During this period, the number of T cells can be gradually reduced except that the serum HIV antibody is positive. However, the virus continues to replicate and infected people are contagious.
Clinical symptoms: None. Duration: There are great differences among individuals. Now it is considered as 2 ~ 10 years, and generally 6 ~ 8 years. This has caused great difficulties for early detection and prevention of patients.
3) The prophase of acquired immunodeficiency syndrome is also called "persistent systemic lymphadenopathy syndrome (PGLS)" and "AIDS-related syndrome (ARC)".
Clinical symptoms: persistent systemic lymphadenopathy. Except inguinal lymph nodes, there were more than 2 swollen lymph nodes in other parts, with a diameter of 65438±0cm, which lasted for more than 3 months. Lymph nodes are swollen and symmetrical, with tough texture, free movement, no tenderness and no response to general treatment. Often accompanied by fatigue, fever, general malaise and weight loss. Excluding other reasons, it can be diagnosed as this period. In some cases, swollen lymph nodes disappear after more than a year, or they can grow again. About 30% patients may only have superficial lymphadenopathy and no other systemic symptoms. Some patients have headache, depression or anxiety, some have sensory nerve endings, and even have symptoms of mental nervous system such as reactive mental disorder, which may be related to the virus invading the nervous system. Some patients have shown signs of immune deficiency. In addition to the above superficial lymphadenopathy and systemic symptoms, various special or recurrent non-fatal infections have occurred repeatedly.
However, in recent years, many scholars advocate canceling the prophase of acquired immunodeficiency syndrome and classifying lymphadenopathy as asymptomatic infection period, but classifying some systemic manifestations as acquired immunodeficiency syndrome period.
4). Acquired immunodeficiency syndrome
Clinical symptoms: In addition to the characteristics of acquired immunodeficiency syndrome, there may be obvious fever, fatigue, night sweats and uncontrollable weight loss (>; 10%), persistent diarrhea and persistent fever (> 38℃) for more than 3 months; And there are serious clinical manifestations of immune deficiency, such as delayed cellular immune response, opportunistic infection, malignant tumor, etc., which can involve various systems and organs of the whole body, and often multiple pathogens cause infection and tumor to coexist.
Infected system or organ:
A) Skin and mucous membrane manifestations: Most patients with acquired immunodeficiency syndrome have skin and mucous membrane infections. Common mucosal infections include oral mucosal candida albicans infection, which is generally asymptomatic. When it affects the pharynx and esophagus, it will cause severe swallowing difficulties. Skin infections include recurrent herpes simplex stomatitis, chronic herpes simplex perianal ulcer, herpes zoster, chickenpox, fungal skin infection and onychomycosis. Homosexuals can also have perianal condyloma acuminatum and contagious molluscum. Seborrheic dermatitis-like lesions often occur in patients' genitals, but also in scalp, face, ears and chest, showing erythema-like and hyperkeratotic scales. It is often butterfly-shaped on the face. The reasons for it were not known
B) Urinary system: kidney damage caused by human immunodeficiency virus.
The incidence of renal damage in patients with acquired immunodeficiency syndrome is about 20% ~ 50%. Opportunistic infection is one of the main factors causing renal damage. Abnormal body fluids and electrolytes caused by infection, septicemia, shock, use of nephrotoxic antibiotics and malignant tumors can all lead to renal damage. Cytomegalovirus and EB virus can cause immune complex nephritis. Pathological changes were focal or diffuse membranous proliferative glomerulonephritis, acute tubular necrosis, tubular atrophy and focal interstitial nephritis. HIV itself may also cause kidney damage, leading to HIV-related nephropathy. Focal segmental glomerulosclerosis is the most common pathological change, and its characteristic changes include the collapse of glomerular vascular plexus, obvious swelling and hypertrophy of glomerular visceral epithelial cells, interstitial edema, fibrosis and inflammatory cell infiltration, and the formation of renal tubular vesicles. Under electron microscope, glomerular endothelial cells, tubular reticular inclusions and so on can be seen. Intravenous drug users are more common in patients with acquired immunodeficiency syndrome. Heroin and its pollutants as antigens can cause immunoreactive renal damage and lead to heroin-related nephropathy. Focal segmental glomerulosclerosis is also the most common pathological change, but the collapse of glomerular vascular plexus, renal tubular vesicles and glomerular endothelial reticular inclusion bodies is not as obvious as HIV-related nephropathy. Clinically, proteinuria, azotemia, acute renal failure or uremia may occur. Heroin-related nephropathy can develop into uremia within six months, while AIDS-related nephropathy can rapidly develop into uremia within two to four months.
C) Respiratory system: pneumonia, Kaposi's sarcoma and tuberculosis mainly caused by opportunistic infections.
Tuberculosis caused by AIDS: Tuberculosis caused by acquired immunodeficiency syndrome is most common in the lungs. Besides common symptoms such as cough, expectoration, dyspnea and chest pain, there are also common symptoms of tuberculosis such as fever, night sweats, anorexia and weight loss. Sometimes its clinical manifestations are difficult to distinguish from pneumocystis carinii pneumonia or other opportunistic infections, and it is necessary to make a differential diagnosis with the help of pathogenic examination and X-ray examination.
Pneumocystis carinii pneumonia: Pneumocystis carinii used to be considered as a protozoa, but now it is confirmed to be a fungus according to morphological and molecular genetic analysis. Infection caused by this bacterium is the most common, accounting for about 80% of pulmonary infection in acquired immunodeficiency syndrome, and it is the main cause of death in acquired immunodeficiency syndrome. This disease is interstitial plasma cell pneumonia caused by pneumocystis carinii. The main pathological changes are diffuse, interstitial and alveolar edema in the lungs, and the alveoli are filled with foamy edema fluid and a large number of pneumocystis. Alveolar wall degeneration and necrosis, a large number of lymphocytes and plasma cells infiltration in pulmonary interstitial. The clinical manifestations are fever, dry cough, increased breathing, dyspnea, cyanosis and ventilation dysfunction; X-ray examination showed interstitial pneumonia. Symptoms get worse and you can die of respiratory failure. The disease can be diagnosed by finding pathogenic bacteria in sputum, pleural effusion, tracheal lavage fluid or endotracheal endomembrane biopsy. In addition, there are cytomegalovirus, Toxoplasma gondii, Cryptococcus, Angiostrongylus, Legionella and so on. It can also cause pneumonia.
Kaposi's sarcoma: Among the patients with extensive skin lesions of acquired immunodeficiency syndrome, Kaposi's sarcoma of the lung was diagnosed clinically in about 20%, and the autopsy detection rate was 50%. However, Kaposi's sarcoma of the lung is rare in patients with acquired immunodeficiency syndrome without skin and mucosal damage. Most patients with this disease have fever, dry cough and dyspnea, but about 40% patients have no such symptoms. Wheezing can occur when there is a large area of endobronchial injury, and wheezing can occur when the larynx is involved. When these injuries lead to bleeding, hemoptysis may occur. Bronchoscopy or endobronchial biopsy can diagnose this disease. Chest x-ray examination is also helpful for diagnosis.
D) Central nervous system: nervous system manifestations of acquired immunodeficiency syndrome.
The main clinical manifestations are dizziness, headache, progressive dementia, hallucination, epilepsy, limb paralysis, spastic ataxia, bladder and rectum dysfunction and cranial neuritis. In addition to the progressive subacute encephalitis caused by HIV, cryptococcal meningitis is the most common, and the clinical manifestations are shown in the relevant chapters. Others include subacute encephalitis caused by cytomegalovirus, toxoplasmosis encephalitis, Toxoplasma gondii infection, Mycobacterium avium infection, brain lymphoma and Kaposi sarcoma. In particular, disseminated Angiostrongylus infection is serious and often life-threatening. The diagnosis mainly depends on cerebrospinal fluid examination, skull X-ray and CT examination.
E) Digestive system: More than 3/4 patients with acquired immunodeficiency syndrome may have digestive system diseases, which affect all parts of gastrointestinal tract. Candida, cytomegalovirus and herpes virus invade the oropharynx and esophagus, causing ulcers. The clinical manifestations are swallowing pain, dysphagia and burning sensation behind the sternum, which can be diagnosed by fiberoptic esophagoscopy. Gastric involvement is relatively small, and occasionally there may be cellulitis gastritis caused by Candida albicans and gastritis caused by cytomegalovirus. Capocci's sarcoma can also invade the stomach, causing corresponding clinical manifestations. Cytomegalovirus, Mycobacterium avium, Mycobacterium tuberculosis and drugs can cause granulomatous hepatitis, acute and chronic hepatitis, fatty liver and cirrhosis. Capocci's sarcoma and other lymphomas can also invade the liver. Various infections and tumors can also invade the pancreas, but the diagnosis is difficult. Cryptosporidium, cytomegalovirus, Mycobacterium avium and Kaposi sarcoma invade the intestine, causing diarrhea and malabsorption syndrome. Cytomegalovirus infection causes ulcerative colitis, which may lead to diarrhea, purulent bloody stool and so on. Among them, Cryptosporidium infection in the intestine is more common, showing chronic persistent diarrhea, which can last for several months and easily lead to the death of patients. The diagnosis depends on stool examination, X-ray, colonoscopy or intestinal mucosal biopsy. Rectal anal cancer is more common in gay men with acquired immunodeficiency syndrome, which may be caused by chronic perianal herpes or human papillomavirus infection during sexual contact.
Acute appendicitis in AIDS patients: although acute appendicitis in AIDS patients is rare, abdominal pain and abdominal signs are similar to gastrointestinal symptoms infected by opportunistic pathogens of AIDS, which makes it difficult to diagnose. Its misdiagnosis rate is high and there are many complications, which need the attention of gastrointestinal surgeons.
F) Blood system: Abnormal blood system is more common in patients with acquired immunodeficiency syndrome. It mainly includes granulocytopenia and thrombocytopenia, anemia and non-Hodgkin's lymphoma.
G) Eye involvement: acquired immunodeficiency syndrome retinopathy.
Eye involvement in patients with acquired immunodeficiency syndrome is also common, but it is easily overlooked. According to literature reports, 40% ~ 92.3% of AIDS patients are complicated with eye diseases, among which fundus damage is more common. It can occur in HIV infection itself or in the secondary infection of conditionally pathogenic microorganisms.
H) Others: retinitis caused by cytomegalovirus and Toxoplasma infection, Kaposi's sarcoma of the eye, etc. HIV itself and opportunistic infections or tumors can also involve cardiovascular and endocrine systems, but the clinical manifestations are often not obvious or slight, which may be related to the low incidence or the death of patients before the clinical manifestations of these system diseases appear. Some patients often have unexplained long-term fever, accompanied by weight loss, general discomfort and fatigue. In some cases, intracellular infection of mycobacteria has been confirmed in bone marrow, lymph nodes or liver biopsy specimens, and its prognosis may be worse than that of Mycobacterium pneumoniae infection alone.
2. Infection in children
Mother-to-child transmission is the main way for children to become infected with HIV. The rest of the patients were infected by blood transfusion in the hospital or treatment in rural health centers in high-incidence areas of AIDS (caused by using unclean syringes).
Childhood acquired immunodeficiency syndrome: After children are infected with HIV, it takes about 5 years for symptoms to appear. Most infants infected with HIV in utero have no clinical symptoms and normal physical examination at birth. 1.5% ~ 25% of perinatal infants infected with HIV become ill in the first few months after birth, and then increase by about 1% every year.
Newborn acquired immune deficiency syndrome: Newborns seldom come into contact with foreign antigens because their immune system is immature and the number of immune memory cells produced is small. After HIV infection, the immune system is more seriously damaged than that of adults, with short incubation period and early symptoms.
Second, the diagnostic criteria
In order to prevent and treat acquired immunodeficiency syndrome in China, according to the specific situation of our country and referring to the classification of HIV infection and AIDS diagnostic criteria of WHO and CDC in the United States, the diagnostic criteria of HIV infection and AIDS in China 1996 was formulated. Diagnostic criteria include acute HIV infection, asymptomatic HIV infection and AIDS.
1. Acute HIV infection
(1) epidemiological history: homosexuals or heterosexuals have multiple sexual partners, or their spouses or sexual partners are HIV-positive; History of intravenous drug abuse; Used imported blood products such as factor VIII; Have a close contact history with HIV/AIDS patients; Have a history of syphilis, gonorrhea and nongonococcal urethritis; History of going abroad; Children born to HIV-positive people; Blood transfusion without anti-HIV testing.
(2) Clinical manifestations: symptoms of upper respiratory tract infection such as fever, fatigue, sore throat and general malaise; Individual headache, rash, meningoencephalitis or acute polyneuritis; There are swollen lymph nodes in the neck, armpit and pillow, similar to infectious mononucleosis; Liver and spleen are big.
(3) Laboratory examination: After the onset, the total number of white blood cells and lymphocytes in peripheral blood decreased, and then the total number of lymphocytes increased to show atypical lymphocytes; CD4/CD8 ratio >:1; Anti-HIV antibody turns negative, and it usually takes 2 ~ 3 months to turn positive, up to 6 months at the longest, and the antibody is negative during the infection window; A few patients were positive for P24 antigen in the initial stage.
2. Asymptomatic HIV infection
(1) Epidemiological history: same as acute HIV infection.
(2) Clinical manifestations: there are often no symptoms and signs.
(3) Laboratory examination: anti-HIV antibody is positive and confirmed by confirmation test; The total number of CD4 lymphocytes was normal or decreased year by year, CD4/CD8 >；; 1; The blood P24 antigen was negative.
3. AIDS
(1) Epidemiological history: same as acute HIV infection.
(2) Clinical manifestations: unexplained low immune function; Persistent irregular low-grade fever >: 1 month; Persistent systemic lymphadenopathy with unknown causes (lymph node diameter >; 1cm)； Chronic diarrhea > 4 times /d, weight loss within 3 months >10%; Complicated with oral candidiasis, pneumocystis carinii pneumonia, cytomegalovirus (CMV) infection, toxoplasmosis, cryptococcal meningitis, rapidly progressing active tuberculosis, cutaneous mucosal Kaposi sarcoma, lymphoma, etc. Dementia is common in young and middle-aged patients.
(3) Laboratory examination: the anti-HIV antibody is confirmed to be positive by confirmation test; P24 antigen positive (units with conditions can be checked); The total number of CD4 lymphocytes was 0.2× 109/L or (0.2 ~ 0.5 )×109/l; CD4/CD8<。 1; Leukocyte and hemoglobin decrease; The level of β2 microglobulin increased; We can find the cause of the above-mentioned co-infection or the pathological basis of the tumor.
Third, classification
AIDS is caused by HIV infection. HIV is a retrovirus. Two kinds of HIV were isolated from AIDS patients, namely HIV- 1 and HIV-2. The genomes of HIV-2 and HIV- 1 are only about 40%-50% homologous. The lesions caused by the two types are similar.
HIV- 1
Including China, is the main epidemic strain in the world. It is divided into three subtypes and 13 subtype.
HIV-2
It is mainly confined to West Africa and Western Europe, and there are a few reports in North America, which are less contagious and pathogenic. Since 1999, a few infected people have been found in some areas of China.
The genomes of HIV-2 and HIV- 1 are only about 40%-60% homologous.