AIDS is a stage of a chronic infectious disease caused by the human immunodeficiency virus. The manifestations of the disease are caused by a progressive decrease in the immune forces of the body, often have a generalized character and are caused by conditionally pathogenic flora. AIDS diagnostics is aimed at determining the presence and quantity of HIV in human blood, antibodies to the virus, and the number of immunocompetent cells. Treatment is aimed at suppressing the reproduction of the pathogen with the help of etiotropic antiviral agents, elimination of microorganisms that provoke secondary pathologies (fungi, bacteria, viruses and others).
B20-B24 Disease caused by human immunodeficiency virus [HIV]
Acquired immunodeficiency syndrome (AIDS) is an indicator of the critical stage of suppression of human immunity, usually develops 5 or more years after infection. For the first time, this syndrome became known in the 80s of the twentieth century, when the deaths of young men from pneumocystis pneumonia (one of the markers of AIDS) began to be registered in the USA. HIV infection is widespread everywhere, the largest number of cases have been registered in African countries. According to UNAIDS, there are 35.1 million adults living with HIV worldwide, of which about half are women. 940 thousand people died from AIDS and associated diseases.
The causative agent of the disease is the human immunodeficiency virus (HIV), related to retroviruses. It is found in different concentrations in blood, saliva, cerebrospinal fluid, vaginal secretions, ejaculate, tears, breast milk and sweat. The ways of HIV transmission are associated with the contact of an infected biological environment with the body of a healthy person, are realized by sexual, intravenous narcotic and vertical (from mother to fetus) methods. Transmission of the virus is possible with repeated use of non-sterile medical instruments, blood transfusion and components, tattooing and piercing.
In the AIDS stage, the causes of clinical manifestations in addition to retrovirus can be pathogens of various nature – protozoa, fungi, bacteria, viruses and even helminths. A significant part of microorganisms belongs to the conditionally pathogenic human flora. The risk groups for the development of secondary infections are the following HIV-infected patients: with a long course of the disease (more than five years) in the absence of treatment, active injecting drug users, pregnant women living in unfavorable sanitary and epidemiological conditions, in contact with patients with infectious pathologies.
The main link in the pathogenesis of AIDS is the reduction of the population of T-lymphocytes. This process takes a long time, due to both the direct cytolytic effect of HIV and the mediated mechanisms of activation of apoptosis in T-helpers. The pathogen triggers the formation of syncytium, which includes host cells containing CD4+ receptors on their surface, which deactivates and depletes the immune pool.
In addition to affecting immunocompetent cells, HIV has neurotropy – the gp120 virus protein is toxic to neurons, the pathogen directly destroys nerve cells, sensitized lymphocytes and antibodies act on brain tissue. A decrease in local, humoral and cellular immunity leads to the activation of persistent infectious agents, which, in the absence of an adequate response from lymphocytes, macrophages and other immunocompetent cells, actively multiply and often cause generalization of infection.
The time that has elapsed from the moment of HIV infection to the first signs of AIDS is calculated in years, sometimes decades. The well-being of patients begins to suffer when symptoms of secondary infections appear, one of the common complaints is a constant increase in body temperature. Fever varies widely, can be accompanied by night sweats, terrific chills, hallucinations and delirium. Often, painless cyanotic-purple nodes are found on the skin of the lower extremities, face and gum mucosa (Kaposi’s sarcoma).
Lesions of the skin and mucous membranes with AIDS occur mainly in the form of candidiasis infection – white curd deposits on the tongue, palate, inner side of the cheeks and genitals. There may be difficulty swallowing, burning in the mouth, pain behind the sternum, a feeling of “lump” in the throat. Vesicles or pigmented traces of shingles are often detected – a condition in which severe pain occurs, bubble rashes along the nerves (intercostal space, face, limbs), passing with residual pigmentation of the affected area.
Against the background of prolonged elevated body temperature, decreased appetite due to unpleasant sensations when eating, diarrhea, weight loss develops. In the case of AIDS, patients may lose 10% or more of their body weight over a short period of time. Liquid stool is watery, without pathological impurities. An increase in lymph nodes may be one of the signs of an extrapulmonary tuberculous process, during which there is a possibility of opening an inflamed lymph node or an entire group with the expiration of a purulent discharge.
A prolonged painful dry cough and increasing shortness of breath indicate that the pulmonary tissue is affected by tuberculous Mycobacterium, pneumocystis, candida, Aspergillus, cytomegalovirus and a number of other microorganisms. Prognostically unfavorable, but often the first signs of AIDS, are the symptoms of central nervous system damage – forgetfulness, decreased attention, loss of communication skills (AIDS dementia), headache, blindness and paralysis (cryptococcosis, toxoplasmosis).
AIDS patients are a category of people with a deep deficiency of immunity. Tuberculosis in these patients is observed in 60% of cases, 80% of patients suffer generalized forms of the tuberculosis process with a high percentage of mortality and disability. Up to 90% of pneumocystis pneumonias are detected in people diagnosed with AIDS. CNS lesions account for about 10% of cases, toxoplasma is the leading etiological agent, tuberculosis meningoencephalitis accounts for 16-23%.
Candidiasis pharyngitis is characteristic of all patients at this stage, fungal lesion of the esophagus is detected in 10-25% of cases, the proportion of this condition progressively increases as the number of T-helpers in peripheral blood decreases. Papillomavirus-associated cervical cancer in patients diagnosed with HIV infection, deep immunodeficiency occurs 9 times more often than in healthy women in the population.
The diagnosis of HIV infection and the presence of AIDS-indicator pathology is established at the consultation of an infectious disease specialist. Other medical specialists are involved according to indications, most often patients with the AIDS stage are consulted by phthisiologists. The main methods used in the diagnosis of nosology include:
- Physical examination. Objective examination aims to detect signs of AIDS, namely, behavioral changes, disorders of consciousness, fever, cachexia, enlargement of lymph nodes, rashes on the skin and mucous membranes. In the lungs, during auscultation, it is possible to record a weakening of breathing and wheezing, in the heart – noises and rhythm disturbances. When examining the tongue and oral cavity, white plaque, neoplasia is often visualized. Palpation of the abdomen allows you to determine the size of organs, symptoms of irritation of the peritoneum, the presence of bulky formations. Plegias, paralysis and meningeal signs may be detected.
- Examination by an ophthalmologist. Ophthalmoscopy is indicated for all HIV-positive patients (even without signs of visual dysfunction) to exclude CMV retinitis. Its objective signs are the presence of precipitates in the anterior chamber of the eye, retinal necrosis, multiple hemorrhages and atrophy of the optic disc. Patients may complain about the deterioration of acuity and blurred vision, the appearance of floating spots and “flies” in front of the eyes. Pain, burning, lacrimation and hyperemia of the conjunctiva are uncharacteristic.
- Laboratory tests. One of the laboratory manifestations of AIDS is considered to be changes in the general blood test: leukopenia, lymphopenia, anemia, often thrombocytopenia. Biochemical indicators do not have specific markers of AIDS, there is often a decrease in total protein, hypoalbuminemia, dyslipidemia, an increase in ALT and AST activity. The study of the immunogram shows a sharp decrease in the number of T-helper CD4 lymphocytes. In the general clinical analysis of urine with HIV-associated kidney damage, proteinuria, lipiduria may be observed.
- Identification of infectious agents. Diagnosis of HIV infection is carried out using blood ELISA (screening method), confirmation of the diagnosis is a positive result of an immune blot. The PCR method is widely used to detect antigens of the most common pathogens of AIDS-indicator diseases: CMV, HSV-1, type 2, herpes viruses types 3, 6, tuberculosis mycobacterium, EBV, toxoplasma, pneumocysts, candida. Microscopic studies of body fluids, biopsies of internal organs, their crops on nutrient media, as well as a diaskin test or a Mantoux test are performed.
- Instrumental techniques. A mandatory examination is chest X–ray, in case of suspected pneumocystosis and tuberculosis – mediastinal tomography, lung MSCT. For neurological symptoms, brain MRI is performed, often with contrast enhancement. Abdominal ultrasound, kidneys, and pelvis is recommended for all HIV-positive persons. Patients with experience of intravenous non-medical use of narcotic drugs are shown ECHO-cardioscopy to exclude infectious endocarditis.
Differential diagnosis of the AIDS stage is carried out based on the leading clinical syndrome. Skin lesions are often similar to the clinic of shingles, syphilis and allergic dermatitis. With chronic candidiasis in the absence of HIV infection, an important sign is the defeat of nails and skin. Pulmonary symptoms can be explained by infectious causes – tuberculosis, ornithosis and worm infestations, chronic pathologies of the respiratory tract (COPD, bronchial asthma). The enlargement of the lymph nodes must be differentiated with lymphogranulomatosis, brucellosis and tuberculosis.
Neurological disorders exclude neurosyphilis, neuroinfections of viral and bacterial nature, disorders of cerebral circulation. Digestive disorders can be caused by Crohn’s disease, esophagitis and ulcerative lesions of the gastrointestinal tract. Diarrheal syndrome is associated with bacterial (salmonella), viral (rotavirus) causes. Malignant neoplasms of various localizations can also manifest symptoms characteristic of AIDS-indicator conditions; the differences are often minimal, the final result is established only when the result of the analysis for HIV antibodies is obtained.
The need for inpatient treatment is determined by the patient’s condition at the time of examination, hospitalization in narrow-profile institutions (anti-tuberculosis, oncological and others) is often indicated. Treatment in intensive care and intensive care units with subsequent long-term rehabilitation is often required. The diet of an HIV-infected person with manifestations of AIDS is determined by the leading clinical syndrome and concomitant diseases, for example, chronic hepatitis and diabetes mellitus. The duration of bed rest depends on the duration of the febrile period and the rate of regression of neurological symptoms.
Etiotropic antiretroviral drugs provide a stop to the natural progression of HIV infection by reducing the amount of virus in the blood, are used mainly in oral forms. For the treatment of opportunistic infections, antibacterial (co-trimoxazole, isoniazid, ciprofloxacin), antifungal (fluconazole, ketoconazole, amphotericin B), antiviral (ganciclovir, acyclovir) drugs are used. According to the indications, chemo-, radiation therapy, surgical interventions are prescribed. Symptomatic treatment may include antipyretic, detoxification, vasoprotective and other means.
Prognosis and prevention
The prognosis for AIDS depends on the timely diagnosis of HIV infection and opportunistic diseases. It is believed that taking antiretroviral drugs prevents the development of systemic forms. Tuberculosis of various localization is the cause of death of HIV-positive patients in 50% of cases, cerebral toxoplasmosis and pneumocystosis of the lungs – in 17%, visceral candidiasis – in 13%. Other conditions account for fewer deaths. The appointment of antiretroviral therapy is indicated for patients within 2 weeks from the start of treatment of the identified opportunistic pathology, with the exception of tuberculosis.
The development of preventive drugs to prevent HIV infection (vaccines) is being actively carried out. The main difficulty of their synthesis lies in the high rate of mutations of the virus. Non-specific prevention includes abstinence from unprotected sexual intercourse and drug use, a policy of monogamy and the use of condoms. It is necessary to introduce educational programs that address HIV infection issues in educational institutions at all levels, conduct mass actions, distribute bulletins, leaflets, videos and clips on television, radio and other mass media.