AIDS, acquired immunodeficiency syndrome (or acquired immunodeficiency syndrome, English: Acquired immunodeficiency syndrome, AIDS, pronounced as AIDS), is a kind of infection by the retrovirus of human immunodeficiency virus (abbreviated as HIV), due to the destruction of the immune system, gradually become the attack of many waiter diseases The syndrome can be transmitted through direct contact with mucosa in the mouth, genitals, anus, etc. or blood, semen, vaginal secretions, or breast milk with the virus. World AIDS Day is celebrated on December 1 every year.
Pathogenesis
AIDS belongs to the human lentivirus group of the genus Lentivirus in the family Retroviridae and is divided into types 1 and 2. HIV-1 is a spherical particle with a diameter of about 100-120 nm and consists of two parts: the core and the envelope. The core consists of two single-stranded RNA strands, core structural proteins and enzymes necessary for viral replication, containing reverse transcriptase, integrase and protease.
HIV-1 is a highly variable virus, and irregular antiviral treatment is an important cause of viral resistance. HIV-2 is mainly found in West Africa, and is now found in the United States, Europe, South Africa, and India. the ultrastructure and cellophilicity of HIV-2 is similar to HIV-1, and its nucleotide and amino acid sequences are significantly different compared to HIV-1.
HIV is less viable in the external environment and less resistant to physical and chemical factors. It is heat sensitive, and HIV can be completely inactivated by treatment at 56°C for 30 minutes and 100°C for 20 minutes. HIV can be inactivated by pasteurization and most common concentrations of chemical disinfectants, such as 75% alcohol, 0.2% sodium hypochlorite, 1% glutaraldehyde, 20% acetaldehyde and acetone, ether and bleaching powder, etc. However, HIV cannot be inactivated by ultraviolet light or gamma radiation.
Epidemiology
1.Epidemiological profile: WHO reported that in 2010, there were 34 million living HIV carriers and AIDS patients worldwide, 2.7 million new infections, and 1.8 million deaths in the year. More than 7,000 people are newly infected every day, and the epidemic is present in all regions of the world, but more than 97% are in middle and low-income countries, especially in Africa. Experts estimate that the worst hit areas of the global epidemic may move from Africa to Asia. China’s CDC estimates that by the end of 2011, about 780,000 people were living with HIV and AIDS in China, with 48,000 new infections and 28,000 deaths for the year. The epidemic has covered all provinces, autonomous regions and municipalities directly under the central government. China is now facing the peak of AIDS incidence and death, and it has started to spread from high-risk groups such as drug addicts and clandestine prostitutes to the general population.
2. Source of infection: HIV-infected people and AIDS patients are the only source of infection for this disease.
3.Routes of transmission: HIV is mainly found in the blood, semen, vaginal secretions and breast milk of infected persons and patients.
① Sexual behavior: unprotected sex with an infected partner, including same-sex, heterosexual and bisexual sexual contact.
②Intravenous drug use: Sharing unsterile injection tools used by an infected person with others is a very important route of HIV transmission.
③Mother-to-child transmission: During pregnancy, delivery and breastfeeding, HIV-infected mothers may transmit to their fetuses and infants.
④Blood and blood products (including artificial insemination, skin grafts and organ transplants). Handshakes, hugs, courtesy kisses, eating and drinking together, sharing toilets and bathrooms, sharing offices, public transportation, recreational facilities and other daily life contacts will not transmit HIV.
4.Susceptible people: The population is generally susceptible. High-risk groups include: male homosexuals, intravenous drug users, frequent sexual contact with HIV carriers, frequent transfusion of blood and blood products, and babies born to HIV-infected mothers.
Clinical manifestations
China divides HIV infection into acute phase, asymptomatic phase and AIDS phase.
(I) Acute phase: It usually occurs about 2-4 weeks after the initial HIV infection. The main clinical manifestations are fever, sore throat, night sweats, nausea, vomiting, diarrhea, rash, arthralgia, swollen lymph nodes and neurological symptoms. Most patients have mild clinical symptoms that persist for 1-3 weeks and then resolve.
HIV-RNA and P24 antigen can be detected in the blood during this period, while HIV antibodies appear several weeks after infection. CD4+ T-lymphocyte count decreases transiently and CD4/CD8 ratio may be inverted.
(ii) Asymptomatic phase
This phase can be entered from the acute phase or directly without obvious acute phase symptoms.
The duration of this phase is usually 6-8 years. However, there are also those who progress rapidly and those who do not progress for a long time. The length of this period depends on the number and type of viruses infected, the route of infection, the immune status of the body and other factors.
(C) AIDS stage
It is the final stage after HIV infection. The patient’s CD4+ T-lymphocyte count decreases significantly, mostly <200/mm3, and the HIV plasma viral load increases significantly. The main clinical manifestations in this stage are HIV-related symptoms, various opportunistic infections and tumors.
HIV-related symptoms: The main manifestations are fever, night sweats, diarrhea that last for more than one month; weight loss of 10% or more. Some patients show neuropsychiatric symptoms, such as memory loss, apathy, personality change, headache, epilepsy and dementia. In addition, persistent generalized lymph node enlargement may occur, which is characterized by
(1) Lymph node enlargement in two or more areas other than the groin;
②Lymph node diameter ≥25px, no pressure pain, no adhesions; ③Duration of more than 3 months.
Common symptoms of HIV-related opportunistic infections and tumors: fever, night sweats, swollen lymph nodes, cough, sputum and blood, dyspnea, headache, vomiting, abdominal pain and diarrhea, gastrointestinal bleeding, dysphagia, decreased appetite, white spots and ulcers in the mouth, various rashes, decreased vision, blindness, dementia, epilepsy, limb paralysis, emaciation, anemia, diarrhea, urinary retention, intestinal obstruction.
Common opportunistic infections
Respiratory system: Pneumocystis carinii pneumonia (PCP), pulmonary tuberculosis, recurrent bacterial and fungal pneumonia.
Central nervous system: cryptococcal meningitis, tuberculous meningitis, toxoplasma encephalopathy, various viral meningoencephalitis
Digestive system: Candida albicans esophagitis, and cytomegalovirus esophagitis, enteritis; Salmonella, dysentery bacillus, Campylobacter jejuni and Cryptosporidium enteritis.
Oral cavity: thrush, tongue hairy white spots, recurrent oral ulcers, gingivitis, etc.
Skin, lymph nodes: herpes zoster, infectious molluscum contagiosum, condyloma acuminata, fungal dermatitis, onychomycosis, lymph node tuberculosis
Eye: cytomegalovirus and toxoplasmosis retinitis.
Common tumors: cervical cancer, malignant lymphoma, Kaposi’s sarcoma, etc.
Hazards of the disease
1.Harm to patients themselves: At present, AIDS has become a chronic disease that can be controlled. However, there are still a considerable number of patients who die or become disabled due to untimely diagnosis and treatment, virus resistance or side effects of drugs. At the same time, due to social discrimination against infected people, it often brings heavy mental pressure to infected people.
2.Harm to others: Infected people can transmit the virus to others through unprotected sex, multiple sexual partners, sharing of needles and intravenous drug use, and mother-to-child transmission.
3.Harm to family and society: Although China has long implemented the policy of “four free and one care” for HIV-infected patients, the treatment of late complications may still bring heavy economic burden and social problems to the family and society.
Disease Screening
Ancillary tests to diagnose and identify HIV infection
①HIV antibody primary screening test (ELISA): High sensitivity, false positives may occur. For patients with positive primary screening, they should be confirmed by confirmatory test.
②HIV antibody confirmatory test (WB): WHO stipulates that as long as there are 2 env bands, it can be judged as positive.
③HIV-RNA: sensitivity is 100%, but occasionally false positives may occur, but false positive results are usually less than 2000 cp/ml, while viral load during acute infection is usually high, averaging at 106 cp/ml.
④p24 antigen: It helps in early diagnosis and has high sensitivity and specificity.
⑤ Rapid detection test: whole blood or blood from capillaries can be collected, and the results are usually available in 15-30 minutes. However, the false-positive and false-negative rates are high, and it is not used as a routine test.
Ancillary tests for complications
AIDS is a disease that can involve all organs of the body, so overall it may involve all kinds of blood tests, excretion, secretion, body fluid tests (including urine, stool, sputum, alveolar lavage fluid, cerebrospinal fluid, pleural fluid, ascites), bone marrow tests and imaging tests for different sites and different kinds of complications (including ultrasound, X-ray, CT, MRI, PET-CT of each site), biopsy. PET-CT), biopsy pathology or cytology (significant for diagnosis and differentiation of tumor, branchial, fungal, cytomegalovirus and other infections). The above tests need to be performed selectively for each patient’s different complications.
Special mention should be made of the need to monitor CD4+ T-lymphocyte count and HIV-RNA in all stages, regardless of whether the disease is stable or not, in order to start antiviral therapy and antiviral medication adjustment in a timely manner.
Diagnostic criteria
1. Diagnosis of HIV infection: epidemiological history: history of unsafe sex, history of intravenous drug use, importation of blood or blood products not tested for anti-HIV antibodies, children born to HIV-positive persons or history of occupational exposure, etc. Clinical manifestations: The manifestations vary by stage, see below. Laboratory tests: The diagnosis of HIV infection must be confirmed by a positive HIV antibody test, and the detection of HIV-RNA and P24 antigen can help in the diagnosis of HIV/AIDS, especially in shortening the antibody “window period” and helping in the early diagnosis of HIV infection in newborns.
(I) Acute phase
Diagnostic criteria: Patients with recent epidemiological history and clinical manifestations, combined with laboratory HIV antibodies from negative to positive can be diagnosed, or only laboratory tests from negative to positive HIV antibodies can be diagnosed. 80% of HIV-infected patients can detect antibodies in the initial screening test 6 weeks after infection, almost 100% of infected patients can detect antibodies after 12 weeks, only a very small number of patients within 3 months or 6 months after infection. Only a very small number of patients can be detected within 3 months or 6 months after infection.
(ii) Asymptomatic phase
Diagnostic criteria: Diagnosis can be made with epidemiological history combined with positive HIV antibodies, or only with positive laboratory tests for HIV antibodies.
(III) AIDS stage
(1) Persistent irregular fever of 38℃ or more for >1 month with unknown cause;
(2) Chronic diarrhea more than 3 times/day, >1 month;
(3) Weight loss of more than 10% within 6 months;
(4) Recurrent oral Candida albicans infections;
(5) Recurrent herpes simplex virus infection or herpes zoster virus infection;
(6) Pneumocystis carinii pneumonia (PCP);
(7) Recurrent bacterial pneumonia;
(8) Active tuberculosis or non-tuberculous mycobacteriosis;
(9) Deep fungal infections;
(10) Occupational lesions of the central nervous system;
(11) Dementia in young and middle-aged adults;
(12) Active cytomegalovirus infection;
(13) Toxoplasma gondii encephalopathy;
(14) Penicillium infection;
(15) Recurrent sepsis;
(16) Kaposi’s sarcoma and lymphoma of the skin mucosa or viscera.
Diagnostic criteria: AIDS can be diagnosed with an epidemiological history, positive laboratory test for HIV antibody, plus any of the above. Or HIV antibody positive and CD4+ T lymphocyte count <200/mm3 can also be diagnosed as AIDS.
Disease treatment Anti-HIV treatment Fold
Highly Active Antiretroviral Therapy (HAART) is the most fundamental treatment for AIDS. And it requires lifelong medication. Treatment goals: to maximize suppression of viral replication, preserve and restore immune function, reduce morbidity and mortality and the incidence of HIV-associated disease, improve the patient’s quality of life, and reduce the transmission of AIDS.
Indications and timing for initiation of antiretroviral therapy.
①Indications and timing for initiation of antiretroviral therapy in adults and adolescents
Treatment is recommended for one of the following conditions: patients in the AIDS phase; acute phase; asymptomatic phase with CD4+ T lymphocytes <350 hiv-rna="">105cp/ml; high risk of cardiovascular disease; comorbid active HBV/HCV infection; HIV-associated nephropathy; pregnancy. Prior to initiation of HAART, the presence of severe opportunistic infections or acute exacerbations of previous chronic disease should be controlled and stabilized before treatment.
②Indications and timing for initiation of antiretroviral therapy in infants and children
Treatment is recommended for one of the following: infants <12 months of age; infants 12 to 35 months of age with a CD4+ T lymphocyte ratio <20% or total <750/ mm3; children 36 months of age or older with a CD4+ T lymphocyte ratio <15% or total <350/ mm3.
Anti-retroviral (ARV) drugs.
(1) Internationally available drugs: more than 30 drugs in six major classes. Nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), integrase inhibitors (raltegravir), fusion enzyme inhibitors (FIs) and CCR5 inhibitors (maraviroc).
②Domestic ARV drugs: there are the first 4 categories and 12 types.
Certain special populations (such as children, pregnant women, combined tuberculosis, hepatitis and intravenous drug users) have their own special characteristics of antiviral therapy, and should be analyzed on a problem-specific basis, and should not be copied from the above protocols.
Adherence is important. Prior to antiviral treatment, there should be adequate communication with the patient so that they understand the need for treatment, the possible discomfort after treatment, the importance of compliance, the need for regular testing after taking the medication, and the need to contact the medical staff promptly in case of any discomfort. Support from their families or friends should also be obtained to improve patient compliance. CD4+ T-lymphocytes, HIV-RNA and routine blood tests should be monitored during antiviral therapy to evaluate the efficacy and side effects.
Treatment of Complications
Anti-infective treatment against various pathogens is performed for all kinds of infections. For example: Candida infection with fluconazole or itraconazole; herpes simplex or herpes zoster with acyclovir or famciclovir and topical interferon; PCP with cotrimoxazole, or combined with clindamycin, and in severe cases with glucocorticoids and even respiratory support; bacterial infection with antibiotics for sensitive bacteria; active tuberculosis with standardized anti-tuberculosis treatment, and tuberculous meningitis or tuberculous pericardial effusion Mycobacterium avium infection requires ethambutol combined with clarithromycin (or azithromycin), and in severe cases, rifabutin or amikacin. Toxoplasma gondii encephalopathy requires etanercept combined with sulfadiazine, and clindamycin for allergic patients.
Complicated tumors: cervical cancer: radical surgery, radiotherapy and chemotherapy are required depending on the stage. Lymphoma requires combined chemotherapy. Kaposi’s sarcoma: only anti-HIV therapy is required for limited cases, chemotherapy is required for disseminated cases.
Disease prognosis
1. Asymptomatic long-term stability: seen in those who have timely antiviral treatment, good compliance with medication, and no viral resistance or serious adverse drug reactions. It is also seen in those who do not progress for a long time after infection.
2.Disability: Some patients may suffer from blindness or other organ dysfunction due to untreated complications.
3, death: seen in patients with advanced stage, not timely antiviral treatment, often die from complications or side effects of drugs.
Disease prevention to prevent HIV infection
① Management of infectious sources: High-risk groups should be tested regularly for HIV antibodies, and infected persons found by medical and health departments should be reported promptly, and HIV-related knowledge should be disseminated to infected persons to avoid transmission to others. The blood, body fluids and secretions of infected persons should be disinfected.
② Cut off the transmission route: avoid unsafe sexual behavior, prohibit sexual promiscuity, and outlaw prostitution. Strictly screen blood suppliers, strictly inspect blood products, and promote the use of disposable syringes. Injecting drugs, especially sharing needles to inject drugs, is strictly prohibited. Do not share dental tools or razors. Do not go to informal hospitals for examination and treatment.
③Protect susceptible people: advocate premarital and preconception medical checkups. HIV-positive pregnant women should be blocked from mother to child. This includes obstetric intervention (termination of pregnancy, cesarean section) + antiviral drugs + artificial feeding. Medical staff should strictly follow medical procedures to avoid occupational exposure. Immediately after occupational exposure, squeeze the wound toward the distal end to squeeze out as much blood as possible from the injury, and then flush the wound with soap solution and flowing water; when contaminating mucous membranes such as the eye, apply plenty of saline to flush the mucous membranes repeatedly; disinfect the wound locally with 75% alcohol or 0.5% iodophor and try not to bandage it.
Then immediately consult an infection specialist for risk assessment and decide whether to administer prophylactic treatment. If medication is required, it should be administered in the shortest possible time (within 2 hours if possible) after the occurrence of occupational exposure, preferably no longer than 24 hours, but even if it is longer than 24 hours, it is recommended to implement prophylactic medication. Post-occupational exposure counseling and monitoring are also required.
Prevention of complications
The best prevention for complications is prompt anti-HIV therapy. patients with CD4+ T lymphocytes <200/ mm3 should be given oral cotrimoxazole 2 tablets/day for prevention of Pneumocystis carinii pneumonia until CD4+ T lymphocytes rise above 200/ mm3 for 3-6 months. Toxoplasma encephalopathy: Avoid raw or undercooked meat and avoid contact with cats and their excreta. Toxoplasma gondii IgG-positive patients with CD4+ T lymphocytes below 100/ mm3 can take oral cotrimoxazole prophylaxis until CD4+ T lymphocytes rise above 200/ mm3 for 3 months. Isoniazid prophylaxis for patients exposed to open tuberculosis.
Diet and lifestyle precautions
Adequate daily intake of energy, high energy, high protein, well digested diet such as meat, eggs and milk is required. Eat plenty of fresh vegetables and fruits. Eat less and more meals. Pay attention to dietary hygiene, especially do not eat raw and cold meat. For patients with diarrhea and indigestion, maintain adequate water intake and eat more liquid food.
Stop smoking and drinking. Exercise properly. Maintain good mood and reduce psychological stress.
Disease care
AIDS is a chronic, progressive, and lethal infectious disease that requires professionally trained caregivers. In addition to HIV, it also includes the care of complications. In addition to paying attention to sterile isolation of HIV, respiratory, body fluid and contact isolation should be done for different pathogens of the patient’s complications. We should strictly operate aseptically and strictly sterilize and isolate; when touching the patient’s blood and body fluids, we should bring gloves, masks or protective glasses, wear isolation clothes and do a good job of self-protection.
In addition, different care should be provided for different clinical symptoms that appear in AIDS patients, such as fever, diarrhea, skin diseases, respiratory symptoms, and gastrointestinal symptoms.
Psychological care: AIDS patients not only have to face the torture of the disease and the threat of death, but also have to bear the pressure and discrimination from the society and family, so they often have emotional abnormalities and even suicidal tendencies. This requires strengthening psychological care. Closely observe the psychological changes of patients, pay attention to listen to patients, establish a good trusting relationship, and help them to build up confidence and hope for life.
Family care: AIDS is a controllable chronic infectious disease. Families should understand basic information about how AIDS is transmitted and how to prevent and treat it, give spiritual support to patients, and help them build up confidence in life. Also pay attention to self-protection to prevent further transmission of HIV.
Expert opinion
Although AIDS is currently a controllable chronic infectious disease, it still has a high mortality and disability rate in China, and patients suffer a lot of pain and stress. The current transmission route is mainly through sexual intercourse, especially male-to-male sex. It is recommended that high-risk groups fix their sexual partners and avoid unsafe sex.
Related information Beijing 17,000 people infected
The Beijing Municipal Health and Planning Commission (BHPC) reported the results of the city’s AIDS epidemic surveillance on July 29, 2014. The results show that since the first AIDS case was reported in 1985, a total of 17,383 cases of HIV infection and patients have been reported in Beijing as of June 30, 2014, with nearly 80% of the infected people being from foreign provinces and cities. Sexual transmission has become the main route of transmission, of which more than 70% are transmitted by men who have sex with men.