An acquired defect of cellular immunity associated with infection by the human immunodeficiency virus (HIV), a CD4-positive T-lymphocyte count under 200 cells/microliter or less than 14% of total lymphocytes, and increased susceptibility to opportunistic infections and malignant neoplasms. Clinical manifestations also include emaciation (wasting) and dementia. These elements reflect criteria for AIDS as defined by the CDC in 1993.
A secondary immunodeficiency syndrome resulting from human immunodeficiency virus (HIV) infection and characterized by opportunistic infections, malignancies, neurological dysfunction (especially subcortical dementia), and a variety of other symptoms. Of the patients dying of AIDS, 90% show histological evidence of subacute encephalitis, which produces a subcortical dementia, with slowed mental processing, poor short-term memory, loss of initiative, and apathy. depression is present in 20%–35% of AIDS patients.
An epidemic disease caused by an infection by human immunodeficiency virus (HIV-1, HIV-2), retrovirus that causes immune system failure and debilitation and is often accompanied by infections such as tuberculosis.
Develops from the HIV virus.
The end-stage manifestations of infection with human immunodeficiency virus (HIV) which destroys important components of the human immune system Persons with the disease develop infections that would not occur with normal immunity The Centers for Disease Control and Prevention have strict criteria for a diagnosis of AIDS. These include a positive test for exposure to HIV and certain abnormalities in T-cell ratios, as well as a number of infections and cancers. Including the following: histoplasmosis, isoporiasis, candidiasis, various forms of pneumonia, esp. Pneumocystis carinii, pneumonia enterocolitis, meningitis esophogitis, encephalitis, chronic mucotaneous herpes simplex, cystome-galovirus infection, chronic progressive multifocal leucoencephalopathy, Hodgkin’s disease, non-Hodgkin’s lymphoma, Burkitt’s lymphoma, liver cancer, cancer of the oropharynx, chronic lymphocytic leukemia, lung cancer, and Kaposi’s sarcoma in persons under 60 years. Also included in the Centers for Disease Control and Prevention’s definition are central nervous system abnormalities caused by infection with HIV itself.
Acronym for acquired immunodeficiency syndrome, caused by HIV (human immunodeficiency virus), that leaves the body vulnerable to a host of life‐threatening illnesses. There is no cure for AIDS, but treatment with antiviral medication can suppress symptoms.
Acquired immune deficiency syndrome; a cluster of disorders such as Kaposi’s sarcoma (KS) and opportunistic infections to which the subject is abnormally vulnerable because of collapse of the immune defense system. The cause is a retrovirus, human T-lymphocytic virus type III (HTLV-III) or HIV (human immunodeficiency virus), which infects and suppresses the T-4 lymphocyte, the focal cell of the immune system. It also directly attacks specific types of cells in the central nervous system and lungs (and perhaps in other tissues as well).
Approximately 70 percent of cases have occurred in homosexual and bisexual males, and about 25 percent in male and female intravenous drug users. There is no known cure and mortality rate is high.
Over 40 percent of AIDS patients develop neurologic complications at some point in their illness. The most common CNS dysfunction is a generalized encephalopathy or progressive multifocal leukoencephalopathy (PML) that includes dementia as a dominant feature. Less commonly, the dysfunction is due to well-defined focal lesions, including opportunistic infection by Toxoplasma gondii, which may invade nervous tissue and give rise to seizures or more subtle alterations in mentation and behavior. Cases with a presenting picture of acute psychosis without dementia have also been described. Myelopathy and peripheral neuropathy are other neurologic complications.
AIDS dementia characteristically begins with impaired concentration and mild memory loss and is often misdiagnosed as “reactive” depression or as a psycho- logic response to the threat of impending death. Over a period of several weeks or months the condition progresses to severe global cognitive impairment. Motor signs, including generalized hyperreflexia and increased tone, may accompany the dementia and some patients develop a spastic-ataxic gait or frank paraparesis.
Syndrome of immune disruption with opportunistic diseases such as pneumonia, Kaposi’s sarcoma, and others due to infection with human immunodeficiency virus by sexual contact and blood-borne exposure.
A life-threatening disorder caused by infection with HIV (human immunodeficiency virus) and characterized by a breakdown of the body’s immune defenses.
The abbreviation for acquired immune deficiency syndrome is AIDS, which signifies a compromised immune system resulting from infection with the human immunodeficiency virus (HIV). The time interval between HIV infection and the onset of AIDS can vary significantly. Without treatment, approximately half of those infected will progress to AIDS within eight to nine years. However, in around one in ten cases, the progression to AIDS is notably slow, spanning up to 20 years or even longer. The prevalence of illness and mortality due to AIDS is a growing global health concern, and presently, there is no known cure or vaccine available.
HIV is transmitted through various body fluids, including semen, blood, vaginal secretions, and breast milk. The primary modes of transmission are sexual contact (vaginal, anal, or oral), direct exposure to infected blood (such as through transfusions or needle-sharing among drug users), and transmission from mother to fetus during pregnancy, childbirth, or breastfeeding. In the past, HIV has also been transmitted through blood products used in treating conditions like haemophilia, kidney transplants, and artificial insemination involving donated semen. However, improved screening techniques have significantly reduced these risks. It’s important to note that HIV is not spread through everyday contact, such as hugging or sharing utensils.
Once in the bloodstream, the virus targets cells that possess a specific receptor called the CD4 receptor on their surface. These cells include CD4 lymphocytes, a type of white blood cell responsible for combating infections, as well as cells in various tissues, including the brain. The virus replicates within the infected cells, causing their subsequent demise and the release of additional virus particles into the bloodstream. In the absence of treatment, the number of CD4 lymphocytes decreases, leading to heightened vulnerability to specific infections and certain types of cancer.
Upon initial HIV infection, some individuals may experience a transient illness resembling infectious mononucleosis. However, many people infected with HIV do not exhibit any noticeable symptoms. Following the initial illness, many individuals remain in good health, while others may encounter symptoms such as swollen lymph nodes, muscle pain, and excessive sweating. Severe bacterial infections, including pneumonia, are frequently observed. Subsequently, nonspecific complaints like weight loss, recurring fevers, night sweats, or unexplained diarrhea, collectively referred to as AIDS-related complex, may serve as warning signs of the development of AIDS.
In addition to the mentioned symptoms, HIV infection can manifest with various skin disorders and a range of viral, fungal, and bacterial infections. Furthermore, the virus can impact the brain, leading to neurological disorders such as dementia.
The development of full-blown AIDS is marked by specific conditions known as AIDS-defining illnesses. These include certain cancers such as brain lymphoma, Kaposi’s sarcoma, and cervical cancer, as well as various infections such as pneumocystis pneumonia, cytomegalovirus infection, toxoplasmosis, diarrhea caused by Cryptosporidium or Isospora, candidiasis, disseminated strongyloidiasis, and cryptococcosis. Many of these infections are classified as opportunistic infections, taking advantage of the weakened immune system.
The development of full-blown AIDS is marked by specific conditions known as AIDS-defining illnesses. These include certain cancers such as brain lymphoma, Kaposi’s sarcoma, and cervical cancer, as well as various infections such as pneumocystis pneumonia, cytomegalovirus infection, toxoplasmosis, diarrhea caused by Cryptosporidium or Isospora, candidiasis, disseminated strongyloidiasis, and cryptococcosis. Many of these infections are classified as opportunistic infections, taking advantage of the weakened immune system.
The confirmation of HIV infection involves conducting a blood test to detect the presence of HIV antibodies (refer to HIV test). It’s important to note that these antibodies may take up to three months to develop following the initial infection. Monitoring the condition involves regular blood tests to assess the number of CD4 lymphocytes in the blood or to measure the viral load, which indicates the amount of detectable virus in the blood. Diagnosis of full-blown AIDS is established through a positive HIV test result combined with the presence of an AIDS-defining illness.
The treatment of HIV infection involves a combination of antiviral drugs, which can effectively slow down the progression of the disease and potentially prevent the development of full-blown AIDS. The primary types of antiviral drugs utilized are protease inhibitors, such as indinavir, and reverse transcriptase inhibitors, such as zidovudine. Multiple drugs are typically administered together to minimize the risk of drug resistance. As for AIDS-defining illnesses, they are treated individually as they arise.
The introduction of combination therapies involving antiviral drugs has significantly reduced AIDS-related deaths in the developed world. Nonetheless, HIV infection continues to pose a life-threatening risk, and the most effective approach in combating it is the prevention of transmission.
The risk of HIV infection can be mitigated by practicing safer sexual behaviors and ensuring that intravenous drug users do not share needles. While there is a small risk to healthcare workers who handle infected needles or blood products, this can be minimized through the implementation of safe practices in the workplace.