The human immunodeficiency virus (HIV) is a lentivirus that weakens the human immune defense and causes acquired immunodeficiency syndrome (AIDS) which is the definite phase of an HIV infection. Often HIV and AIDS are used synonymously but not ever infected person also suffers from a complete immune deficiency. Years to decades can pass between a first HIV infection and a possible onset of AIDS. [1] [2] [3]

Statistics
According to estimates, around 35 million people worldwide are infected with the HI-virus. [4] While in West Europe the percentage of infected people represents one tenth of a percent, in some African countries around 25 per cent are infected. [1] [5]

History
The origin of the virus is still unclear but there are several conspiracy theories. According to the most plausible theory the virus is believed to have originated in primates and have transferred to humans in the 20th century. [6] [7]

In 1983, the French virologists Françoise Barré-Sinoussi and Luc Montagnier made a clear statement about the HI-virus. In 2008 they received the Nobel Prize in Medicine for their achievement. Their discovery enabled the development of diagnoses and therapies. [1] For many affected people it was too late since the HIV epidemic claimed the life of countless people in the 1980's. The victims include the singer of Queen, Freddie Mercury (1946-1991), the French philosopher, Michael Foucault (1926-1984), the American graffiti artist, Keith Haring (1958-1990) and the Israeli singer and composer, Ofra Haza (1957-2000). [8]

Transmission
Infection with HIV occurs by the transfer of blood, sperm, vaginal fluids, or breast milk. [8]. Vaginal or anal intercourse as well as intravenous drug abuse due to nonsterile needles cause a higher transmission rate of HIV. [4]

Symptoms
An HIV infection can be divided into three phases: [9] [2] [10]

First stage: Acute infection and latency
The start of a primary HIV infection is marked by a strong immune defense. However, the virus cannot be eliminated by the human defense cells and stays in the blood stream for life.

Infected individuals may experience no symptoms but in 40 to 90 per cent of all cases many individuals develop an illness called acute HIV infection after days to weeks post-exposure. The most common symptoms may include fever, headache, joint pain, swollen lymph nodes and fatigue. The duration of symptoms varies; averaging 28 days and usually lasts for two weeks.

The following latency phase on average lasts for ten years. During this time the body can fairly control the virus.

Second stage: Symptomatic stage
The immune system becomes increasingly weaker. Symptoms like night sweats, fever attacks and diarrhea are first indicators. Infected individuals often suffer from fungal infections of mucous membranes and skin diseases like shingles.

Third stage: AIDS
The symptoms of AIDS are primarily the result of conditions that do not normally develop in individuals with healthy immune systems. Most of these conditions are opportunistic infections such as herpes simplex, herpes zoster, or different fungi. [INFECTIONS] Symptoms include pneumonia, chronic diarrhea, fever, skin alteration and eye inflammation. People with AIDS also have an increased risk of developing various cancers. Additionally, the brain and the nervous system are damaged and the brain activity increasingly declines.

Treatment
Modern HIV therapy can control the virus quite well since the immune defense stays intact. There is still no vaccination or cure for the virus, which remains in the human body. [2] [10]

Protection
An effective form of protection is the consequent use of condoms and femidoms during intercourse since only a certain amount of viruses cause an infection. In case of a possible contamination a prophylactic therapy might impede the virus spread within the body. [4]

Social contact with HIV positive individuals such as handshakes, hugs, kisses, coughs, sneezes, the common use of kitchenware and towels etc. is not contagious. An HIV test is recommendable, especially in case of monogamous relationships in which no condoms or femidoms are used. [11]


Further Links:
Die Aidshilfen Österreichs (Website)
Deutsche AIDS-Hilfe (Website)
AIDS.gov (Website)
Australian Federation of AIDS Organisations (Website)