What is AIDS (Acquired Immune Deficiency Syndrome)?|
AIDS is the disease caused by the human immunodeficiency virus or HIV. The virus is known to often not cause the disease for a long time after first exposure i.e. it has a long latency period. AIDS was first recognised in America in 1981, and today is considered to be one of the most devastating health problems worldwide.
Transmission of AIDS can occur in a number of ways and the risk factors for contracting HIV varies. Transmission is usually via sexual contact with a HIV infected person. Those at greatest risk are ones that have anal intercourse and do not practice safe sex. Heterosexual transmission is also reported.
Pregnant woman may pass on the virus to their fetus, especially if they are in the advanced stages of the disease or when breast-feeding. High-risk individuals are those who have bi-sexual partners, haemophilia (a condition which requires blood transfusions), drug users, and those who live in a community where HIV is common in the heterosexual community.
Those people who are exposed to contaminated blood products are also at risk. Since the introduction of blood product screening the incidence in contamination due to blood transfusions has dropped markedly. The risk of HIV infection increases in communities where there is a high population of drug abusers who inject frequently and share needles. Health professionals who may experience needle stick injuries are at risk of being infected by the virus.
Handshakes, coughing / sneezing, insect bites (e.g. Mosquito) or casual non-sexual contact have not been proven as causes for HIV transmission.
What are the symptoms of AIDS?
As the HIV virus targets the body's immune system, namely through immunodeficiency (damage to the immune response), autoimmunity (production of antibodies - response to foreign particles- to the body's own cells), and nervous system dysfunction, AIDS may affect any major organ system within the body.
Immunodeficiency results from the virus binding to a protein (CD4) found on white blood cells (cells within the immune system).
Once bound, the virus can replicate within the cell and kill it. It also disrupts the function of any remaining cells with the CD4 protein. The process of disruption and death to cells is not fully understood. Because the immune system has been compromised opportunistic infections and cancers can take advantage without a full defence response.
In AIDS the body produces antibodies which bind to the body's own platelets (involved in blood clotting and tissue repair). Once antibodies are bound, the platelets are marked for removal from the system via the spleen. The condition where the platelet count drops below normal because of the immune system is known as immune-related thrombocytopenia and may be present in some AIDS cases.
Attack on the nervous system by the virus is not well understood, as the virus appears not to attack the cells directly.
AIDS usually progresses through three stages, which varies greatly between patients.
Acute Retroviral Syndrome
This may mimic other varieties of viral infectious states, such as glandular fever (Infectious Mononucleosis, Epstein-Barr virus) and may be the first sign of HIV infection. Symptoms may include fever, fatigue, muscle aches, decreased appetite, digestive disturbances, weight loss, skin rashes, headache and prolonged (chronic) swollen lymph nodes. A few patients may also experience a type of meningitis where brain and spinal cord membranes become inflamed. This syndrome is commonly apparent 1-6 weeks after infection of the virus and usually lasts for 2-3 weeks. Children are less likely to present with syndrome than adults are.
A latency period
This occurs after the initial acute viral syndrome, where the virus may lie latent for as long as 10 years or more before symptoms of the advanced disease develop. However, during this perio