Discovery of AIDS
Homosexual men with symptoms of a disease that now are considered typical of the acquired immunodeficiency syndrome (AIDS) were first described in Los Angeles and New York in the year 1981. The men presented with an unusual type of lung infection called Pneumocystis carinii (now known as Pneumocystis jiroveci) pneumonia (PCP) and rare skin tumors called Kaposi's sarcoma.
The patients were also noted to have a severe reduction of a type of cell in the blood that is an important part of the immune system, called CD4 cells. These cells are often referred to as T cells which help the body fight against infections. Shortly, this disease was recognized throughout the United States, Western Europe, and Africa. In 1983, researchers in the United States and France described the virus that causes AIDS, now known as the human immunodeficiency virus (HIV) belong to the group of viruses called retroviruses. In 1985, a blood test was discovered to measure antibodies to HIV that are the body's immune response to the HIV. This blood test remains as the best method for diagnosing HIV infection. Recently, tests have become available for assessing the same antibodies in the saliva and urine, and some can provide results within 20 minutes of testing.
The patients were also noted to have a severe reduction of a type of cell in the blood that is an important part of the immune system, called CD4 cells. These cells are often referred to as T cells which help the body fight against infections. Shortly, this disease was recognized throughout the United States, Western Europe, and Africa. In 1983, researchers in the United States and France described the virus that causes AIDS, now known as the human immunodeficiency virus (HIV) belong to the group of viruses called retroviruses. In 1985, a blood test was discovered to measure antibodies to HIV that are the body's immune response to the HIV. This blood test remains as the best method for diagnosing HIV infection. Recently, tests have become available for assessing the same antibodies in the saliva and urine, and some can provide results within 20 minutes of testing.
Transmission of HIV
The virus is present in the blood and genital secretions of virtually all individuals infected with HIV, regardless of whether or not they have symptoms. The spread of HIV can occur when these secretions come in contact with the following tissues:
1. Lining of the vagina
2. Anal area
3. Mouth
4. Eyes (the mucus membranes)
5. A break in the skin, such as from a cut or puncture by a needle.
The most common ways in which HIV is spreading throughout the world include:
1. Sexual contact
2. Sharing needles
3. Transmission from infected mothers to their newborns during pregnancy, labor (the delivery process), or breast-feeding.
Sexual contact
Sexual transmission of HIV spreads from men to men, men to women, women to men, and women to women through vaginal, anal, and oral sex. The best way to avoid sexual transmission is to avoid sex until it is certain that both partners in a monogamous relationship are not HIV-infected. HIV antibody test can take up to 6 months to turn positive, so both partners would need to test negative 6 months after their last potential exposure to HIV.
The next best method is the use of latex barriers for a safer sex. This involves placing a condom on the as soon as an erection is achieved in order to avoid exposure to pre-ejaculatory and ejaculatory fluids that contain infectious HIV from penis.
Sharing needles
Exposure to infected blood usually results from sharing needles. It not only spreads HIV but also other diseases including hepatitis. So the needles should never be shared. At the beginning many individuals acquired HIV infection from blood transfusions or blood products, such as those used for hemophiliacs. Currently, the blood is tested for antibodies to HIV before transfusion so the risk of acquiring HIV from a blood transfusion is extremely small and is considered insignificant.
Symptoms of HIV
The most common symptoms of primary HIV infection are:
1. Fever
2. Aching muscles as well as joints
3. Sore throat
4. Swollen glands
During the asymptomatic stage of infection, billions of HIV particles (copies) are produced every day and they circulate in the blood. The virus replicates and transcribes the viral protein. This production of virus is associated with a fall (at an inconsistent rate) in the number of CD4 cells in the blood as the years pass. The virus is not only found in the blood but also throughout the body, especially in the lymph nodes, brain, and genital secretions. The time from which HIV infection occurs to the development of AIDS varies. Some people develop symptoms within 1 year of infection. Others, however, remain completely asymptomatic, i.e., symptomless after as many as 20 years. The average time for progression of the initial infection to AIDS is 8 to 10 years. The reason why different people experience clinical progression of HIV at different rates remains still as an area of active research.
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