AIDS - Acquired Immune Deficiency Syndrome

It is a human disease characterized by progressive destruction of the body’s immune system. It is widely accepted that AIDS results from infection with HIV (Human Immunodeficiency Virus).

AIDS is currently considered incurable; where treatments are unavailable (mostly in poorer countries) most suffers die within a few year of diagnosis. In developed countries, treatment has improved greatly over the past decade, and people have lived with AIDS for ten to twenty years.
In 2003, it was estimated that 40 million were infected with AIDS and 5 million contracted HIV.

AIDS was first noticed among homosexual men and intravenous drug users in the 1980s. By the 1990s the syndrome had become a global epidemic and in 2004, 58% of those with AIDS were women. While homosexual men continue to suffer higher per capita AIDS rates, the majority of victims are currently heterosexual women, men, and children in developing countries.

Symptoms
HIV is transmitted by body fluids, such as blood, semen and vaginal secretions. It causes disease by infecting CD4+ T cells, a type of leukocyte that normally coordinates the immune response to infection and cancer. HIV also infects brain cell, causing some neurological disorders.

Today, diagnosis is based on CD4+ T cell counts. This allows for earlier diagnosis considerably to original method based on the opportunistic diseases affecting the patient.

Opportunistic diseases associated with AIDS are e.g.: candidiasis, coccidiodomycosis, cytomegalovirus disease, herpes simplex virus infection, histoplasmosis, dementia, chronic intestinal isosporiasis, mycobacterium infections, pneumonia, salmonella septicaemia, neurological toxoplasmosis.

Origins of AIDS
HIV is closely related to the simian immunodeficiency viruses. These are lentiviruses, and are endemic to many African monkeys and apes, in which they are largely asymptomatic.

Studies suggest that the virus spread initially in West Africa, but it is possible that there were several separate initial sources, corresponding to the different strains of HIV (HIV-1 and HIV-2).

The earliest human fluid sample known to contain HIV was taken in 1959 from a British sailor, who apparently contracted it in what is now the Democratic Republic of the Congo.
It is believed that the virus was spread via sexual activity, possibly including with prostitutes, in Africa’s rapidly growing urban areas. As unwittingly infected people traveled the virus spread from one city to another, and air travelers carried the virus to other continents.

Current medical understanding of AIDS
Currently the most common ways to contract HIV are via unprotected sexual activity and the sharing the needles by users of intravenous drugs. The virus is rarely transmitted from mother to child in the womb, but HIV can be transmitted during childbirth or through breastfeeding. Blood transfusions and the use of blood products to treat haemophilia have also been major routes of infection in the past, leading to stricter screening procedures (but despite these new measures such cases are still reported occasionally).

Not every patient who is infected with HIV is considered to have AIDS. A person who is infected with HIV is said to be HIV+. An uninfected individual is said to be HIV-.

Primary infection with HIV is called seroconversion. Symptoms of seroconversion illness include mild flu-like symptoms such as fever, aching muscles and joints, sore throat, and swollen glands, but may also include other symptoms such as rash. But there are people who experience no symptoms at all at this stage.

Regardless of the presence or absence of initial symptoms, all newly infected individuals become asymptomatic. At this stage, the virus is still multiplying rapidly, unchecked, because the body has not yet started to produce antibodies to the virus in sufficient quantities to reach equilibrium.
The time from infection with HIV to a diagnosis of AIDS varies. Some patients develop symptoms within a few months of infection, while others are known to have remained completely asymptomatic for as long as 20 years. This is the subject of ongoing study. The average time of progression from initial infection to AIDS is eight to ten years in the absence of treatment.

Treatments and vaccines
There is currently no cure or vaccine for HIV or AIDS. Newer treatments, however, have played a part in delaying the onset of AIDS, on reducing the symptoms, and extending patient’s life spans. Over the past decade the success of these anti-retroviral treatments in prolonging, and improving, the quality of life for people with AIDS has improved dramatically.
There is ongoing research into developing a vaccine for HIV and in developing new antiretroviral drugs.

Prevention
Despite widely publicized fears about the possible “casual transmission” of HIV and AIDS, the risk of infection is virtually eliminated by following simple precautions and is entirely eliminated by abstaining from sexual activity an avoiding blood transfusions and the sharing of needles.
The only proven cause of transmission is the exchange of bodily fluids, in particular blood and genital secretions.