Ailments and Situations - Acquired Immune Deficiency Syndrome or AIDS - HIV Transmission, Strains and Functions

The virus is transmitted by contaminated blood and other body fluids. One group considered at high risk include people with multiple sexual partners who engage in unprotected sex. Wearing a condom, however, does not afford you with 100% security. Other high risk groups include IV drug users (sharing needles) and their sexual partners and people who received blood transfusions or blood products before blood was screened for HIV.

HIV can be passed by an infected mother to her child during pregnancy or delivery or post-partum in breast milk. Encouragingly, efforts to increase public awareness about HIV seem to have caused a leveling off of the incidence of HIV infection among the gay community. Despite these efforts, there is an alarming rise in the incidence of HIV infection among heterosexual women and children, especially teens.

There are two strains of HIV; HIV-1 and HIV-2. AIDS in the Western Hemisphere primarily results from HIV-1 infection with HIV-1 while African cases are predominately due to HIV-2. One theory suggests both strains originated in Africa. HIV belongs to a family of viruses known as Lentivirinae. "Lenti" is the Latin word for "slow", and is used to describe this family of viruses as they cause disease slowly.

HIV is a retrovirus. It contains two strands of RNA (genetic material) and an enzyme called "reverse transcriptase". The virus uses this enzyme to create a single strand of DNA (another form of genetic material) from the strands of RNA in a process called "reverse transcription". The DNA is then processed to form a single piece of double-stranded DNA. In this form, the viral genes can be incorporated into human DNA. It can exist for a long period of time in a latent state and the infected cell may show no outward sign of infection. Eventually, and for unknown reasons, viral synthesis begins. New viral particles are produced and released into the blood stream to infect other cells.