Ailments and Situations - Acquired Immune Deficiency Syndrome or AIDS - Causes

AIDS is caused by the human immunodeficiency virus (HIV). Although virtually all people who are HIV positive eventually get AIDS, not everyone does. Some researchers believe that the presence of other STDs increase the risk of contracting HIV and also increase the chance of developing AIDS. Those who have not developed AIDS are studied intensely to determine variations between this group and the rest of the HIV positive population.

Virtually every (but not all) HIV positive people develop AIDS. To date, AIDS is fatal. Death is not directly due to the virus itself, but rather opportunistic infections that arise due to the severely depressed state of the immune system. Opportunistic infections are those that are not often seen in people with a healthy and properly functioning immune system. These infections are the leading cause of death among AIDS patients. Many of these infections are outlined below.

The most common opportunistic infection includes pneumonia caused by the fungus Pneumocystis carinii. This is the major cause of death among AIDS patients. You may only have a slight fever or none at all. You are likely to be extremely weak, have shortness of breath or difficulty breathing, and your skin and mucous membranes may be bluish or purplish (cyanotic). This form of infection is also known as interstitial plasma cell pneumonia or pneumocytosis.

Many AIDS patients also suffer from systemic fungal infections typically caused by Candida albicans. Candidiasis is often one of the first symptoms in an HIV positive person, along with oral hairy leukoplakia (see below). For more information see Candidiasis.

Toxoplasmosis is a disease caused by the protozoan Toxoplasma gondii. Symptoms include fever, lymphadenopathy, headache, myalgia, arthralgia, malaise, and fatigue. It can also lead to encephalomyelitis, corioretinopathy, maculopapular rash, and pneumonitis. Toxoplasmosis is often fatal due to the encephalopathy that occurs. This disease can be passed through the placenta to the fetus and several abnormalities may occur.

Isosporiasis is a disease caused by infection of the small intestine with one of a number of species of the genus Isospora. Though an infection is quite likely, an intact immune system keeps this fungus in check. AIDS patients infected by this organism suffer from mucousy diarrhea. It is very resistant to treatment.

Infection by Cryptococcus neoformans causes a disease called cryptococcosis and can be a pulmonary, disseminated, or meningeal infection. The most common form involves the central nervous system (CNS) and causes subacute or chronic meningitis. This infection is also known as Busse-Buschke disease.

Cryptosporidiosis is a waterborne, enteric disease that manifests as prolonged, severe diarrhea. It is caused by protozoa of the genus Cryptosporidium and can be fatal.

Coccidioidomycosis is caused by inhaling dust particles containing spores of the fungus Coccidioidomycosis immitis. This is a systemic disease that can be benign, severe, or fatal. If benign, lesions occur in the upper respiratory tract and the lungs. In more severe cases, lesions spread to other organs, bones, joints, skin, and subcutaneous tissues. This disease is also known as Posadas disease.

Infection with Histoplasma capsulatum can cause a disease called histoplasmosis. This is a systemic fungal disease acquired by the inhalation of spores in soil dust and leads to primary benign pneumonitis. Occasionally, lesions form in the lungs. Signs and symptoms include fever, emaciation, splenomegaly (enlarged spleen), and leukopenia (low leukocyte count). This disease is also known as Darling's disease.

Along with candidiasis, oral hairy leukoplakia are one of the first symptoms of HIV infection and is cause by the Epstien-Barr virus (EBV). White, raised lesions with a corrugated or "hairy" surface appear on the tongue. These lesions may become cancerous and may or may not spontaneously regress.

Shingles is a disease caused by the activation of latent varicella zoster virus in a dorsal nerve root and is the same virus that causes chicken pox. The disease is characterized by the presence of small vesicles on one side of the body and follow the course of a nerve. It may be accompanied or followed by severe, post-herpetic pain.

Cytomegalovirus (CMV) can cause "CMV disease" or cytomegalic inclusion disease. This group of viruses belong to the Herpesviridae family and have special affinity for salivary glands, although it can affect various organs. Signs and symptoms include fever, jaundice, hepatomegaly (enlargement of the liver), splenomegaly (enlargement of the spleen), purpura, and thrombocytopenia. This disease can be passed on to the fetus and may result in malformation and even death. Latent CMV can be reactivated and cause pneumonia, encephalitis, blindness, and inflammation of the gastrointestinal tract.

Progressive multifocal leukoencephalopathy (PML) is a rare, subacute, disease caused by JC virus (a human polyoma virus). It is characterized by areas of demyelination of nerve cells that comprise the white matter of the nervous system and severely altered neuroglia.

Some people with AIDS suffer from bronchitis caused by herpes simplex virus (see Bronchitis for more information). This virus also causes persistent and painful sores in the skin around the mouth, genitals, or anus.

Tuberculosis is caused by Mycobacterium tuberculosis. It has the ability to affect almost any tissue or organ of the body, but most commonly affects the lungs. Lesions are referred to as tubercles and can undergo a process called caseation necrosis, whereby the tissue dies. Local symptoms vary, but systemic symptoms include sepsis, with fever, sweats, and emaciation. If not treated, it is usually fatal.

Mycobacterium avium-intracellulare complex (MAC) is a difficult infection to treat and is antibiotic resistant. M. avium causes TB in birds and has just recently been linked to opportunistic infections in humans.

Recurrent Salmonella septicemia is a systemic disease. It is caused by the recurrent spread of Salmonella bacteria and their toxins via the bloodstream.

Kaposi's sarcoma (KS) is a rare form of cancer that often appears in people with AIDS. It is a cancer of the cells that line the walls of blood vessels and leaves characteristic purple patches or lesions on the skin, aiding diagnosis. It used to be a very rare tumour of endothelial cells and mesenchymal spindle cells. AIDS-related KS differs from the classic form in that the tumours can appear anywhere on the body, instead of just the lower limbs. KS can be disseminated to internal organs, its spread is more aggressive, and its pathogenesis is poorly understood. AIDS-related KS appears mostly in males. The mode of HIV infection may play a significant role as it has been noticed that of the men that were infected due to transfusion of tainted blood products, very few develop KS. It is thought that another venerally-transmitted organism is also implicated in the development of AIDS-related KS.

Cervical cancer is a malignant neoplasm and is derived from the epithelial tissue of the cervix. The risk of developing this cancer is increased in women with HIV.

Non-Hodgkin's lymphoma is among the most common AIDS-related malignancies. It is defined as a lymphoma other than Hodgkin's disease and is divided into low, intermediate, and high-grade malignancy, differing in ease of treatment and prognosis.

Burkitt's lymphoma is a form of malignant lymphoma caused by EBV. EBV that latently infects cells can sometimes undergo malignant transformation. If T cells fail to respond to and destroy this transformation, this type of B-cell lymphoma may occur.

Other malignant disease include primary lymphoma of the brain and immunoblastic lymphoma.

AIDS dementia complex (ADC) is subacute or chronic encephalitis associated with HIV-1 infection. It is the most common neurological complication in later stages of AIDS and manifests as a progressive dementia with motor abnormalities. The dementia includes loss of cognitive and intellectual function with disorientation, impairment of memory, judgement, and intellect. This occurs without impairment of perception or consciousness. ADC is also known as HIV-related encephalopathy.

People with AIDS often suffer from a number of neurological problems, some of them related to balance and gait (method of foot movement). Often, people in later stages of the disease are unsteady on their feet, tend to loose their balance, and fall.

HIV wasting syndrome is a condition whereby you lose 10% of your body weight and is associated with diarrhea or fever lasting over one month.

Idiopathic thrombocytopenic purpura (ITP) is a systemic illness of unknown cause (idiopathic). Extensive purplish patches (ecchymoses) and hemorrhages occur from mucous membranes. Platelet counts are very low due to destruction by macrophages. There is a potential for life-threatening bleeding to occur, especially intracranially. This disease is also known as immune thrombocytopenic purpura, purpura hemorrhagica (1), and thrombopenic purpura.

Cervical dysplasia is an abnormal tissue development of the cervix. It seems to regress frequently but has the potential to develop into a carcinoma after long periods of time.

Pelvic inflammatory disease (PID) is an acute or chronic inflammation in the female pelvic cavity, where suppurative lesions form in the upper genital tract. It is most commonly caused by STDs that have made their way up to the uterus, fallopian tubes, or ovaries due to childbirth, intercourse, or surgical procedures such as the insertion of an intrauterine device (IUD) or abortion. PID can be symptomatic or asymptomatic. Scarring of the lesions occurs and this can lead to infertility. It may also increase the risk of ectopic pregnancy (implantation and development of a fetus at a site other than the uterus).

People with AIDS often suffer from peripheral neuropathies. These are diseases involving the peripheral nervous system. Symptoms can include numbness and tingling of extremities, pain, and weakness.

Chronic ulcers are also a problem for people with AIDS see Ulcer for more information. Many people with AIDS also suffer from decubitus ulcers or pressure sores if bed ridden. These ulcers and sores appear over bony prominence and are caused by a circulatory defect.

Enteric helminthic infections often occur in people with AIDS. These are infections with intestinal worms, causing dysentery with frequent, watery, stools with occasional blood and mucous, pain, fever, dehydration and painful spasm of the anal sphincter. In AIDS patients, this is often caused by the nematode Strongyloides stercoralis, a small roundworm that is widespread in all tropical regions.