Understanding AIDS

Updated May 8, 2019 | Infoplease Staff

Acquired Immune Deficiency Syndrome, or AIDS, was first reported in mid-1981 in the United States; it is believed to have originated in sub-Saharan Africa. The human immunodeficiency virus (HIV) that causes AIDS was identified in 1983, and by 1985 tests to detect the virus were available. The credit for discovering the AIDS virus is jointly shared by Dr. Robert Gallo, a researcher at the National Cancer Institute, and Luc Montagnier of the Pasteur Institute, France.

Destruction of Immune System

A fatal and incurable disease caused by HIV, AIDS attacks and destroys the immune system, gradually leaving the individual defenseless against illnesses that lead to death. These illnesses are referred to as “opportunistic“ infections or diseases: in AIDS patients the most common are Pneumocystis carinii pneumonia (PCP), a parasitic infection of the lungs, and a type of cancer known as Kaposi's sarcoma (KS). Other opportunistic infections include unusually severe infections with yeast, cytomegalovirus, herpes virus, and parasites such as Toxoplasma or Cryptosporidia. Milder infections with these organisms do not suggest immune deficiencies. Symptoms of full-blown AIDS include a persistent cough, fever, and difficulty in breathing. Multiple purplish blotches and bumps on the skin may indicate Kaposi's sarcoma. The virus can also cause brain damage.

People infected with the virus can have a wide range of symptoms-from none to mild to severe. At least a fourth to a half of those infected with HIV will develop AIDS within four to ten years. Many experts think the percentage will grow much higher.

Transmission

Although the first reported cases involved homosexual men in Los Angeles who were infected through sexual contact, the principal mode of transmission throughout the world is through the exchange of bodily fluids during heterosexual intercourse. According to the World Health Organization, extensive spread of HIV appears to have begun in the late 1970s and early 1980s. It spread in men and women with multiple sexual partners in East and Central Africa and among homosexual and bisexual men in certain urban areas of the Americas, Australasia, and Western Europe.

In addition to sexual contact, AIDS has been spread by intravenous drug users sharing infected hypodermic needles. The virus can also be passed on through transfused blood or its components. It may also be transmitted from infected mother to infant before, during, or shortly after birth.

Two major types of HIV have been recognized, HIV-l and HIV-2. HIV-l is the dominant type worldwide. HIV-2 is found principally in West Africa, but cases have been reported in East Africa, Europe, Asia, and Latin America. There are at least ten different genetic subtypes of HIV-l, but their biological and epidemiological significance is unclear at present. Both HIV-l and HIV-2 are transmitted in the same ways.

Pandemic

With no cure at present, prudence could save thousands of people who have yet to be exposed to the virus. Use of condoms lessens the possibility of transmission, as does the elimination of sharing hypodermic needles. The fate of many will depend less on science than on the ability of large numbers of human beings to change their behavior in the face of growing danger.

The introduction of highly active antiretroviral therapy in 1996 was a turning point for those with access to sophisticated health-care systems. Although they can't cure HIV/AIDS, antiretrovirals (ARVs) and their use in combination, “cocktails,“ have dramatically reduced mortality and morbidity and prolonged and improved the lives of sufferers. However, 95% of people with HIV/AIDS live in developing countries, where access to these medicines remains unacceptably limited and the costs prohibitively expensive. Progress has recently been made in India, however, as Indian pharmaceutical companies are producing generic versions of ARVs and selling them for less than $1 a day. Another obstacle is that not everyone can tolerate the potent medications and their side effects. Doctors are also reporting a significant increase of patients with drug-resistant HIV strains. Some 100 separate drugs are either in use or being tested for use against AIDS. In July 2006, the FDA approved the first single-pill, once-a-day AIDS treatment, thereby allowing patients to manage their disease without a complicated regimen of drugs that must be strictly followed to be effective. The pill, called Atripla, is considered an enormous breakthrough in AIDS treatment, and will help prevent the disease from mutating into drug-resistant strains, which occurs when drugs are not taken regularly.

On a global scale, more than 37 million people have died to date. There are just under 37 million people living with HIV, including 2.6 million children, most of whom live in sub-Saharan Africa and were infected by their HIV-positive mothers during pregnancy, childbirth, or breastfeeding. Each day more than 650 children become newly infected with HIV. At the end of 2014, 15 million HIV-positive people were receiving antiretroviral treatment (ART) worldwide. However, that leaves almost 22 million still not accessing ART.