The disease AIDS develops from an infection HIV and is caused by the v irus immunodeficiency h umana. HIV and substance containing RNA ( ribonucleic acid ), unlike many other viruses or human cells whose genetic information is stored in the form of DNA (deoxyribonucleic acid). Therefore, HIV is defined rather as an RNA virus within the group of retroviruses.
The: two types of HIV are known HIV-1 , present worldwide, and HIV-2 , which is found mainly in South Africa.
Both virus types differ in their genetic substance, RNA. Thus, HIV-2 RNA, called AIDS virus from monkeys is similar to the green monkeys, while HIV-1 is more like chimpanzees. It is likely that before the explosion and rapid spread of AIDS in the 1980s had many people already infected with this virus monkey.
HIV genetic material is surrounded by a protein coat . This property
enables the envelope virus from attaching to the human immune
cells such as helper T cells (also known as T cells). Infected
T cells are destroyed by the virus, so that occurs weakening the
immune system over time. This favors the emergence of other diseases.
HIV is transmitted primarily by blood and sperm. Therefore, people who have unprotected sex ordrug addicts who exchange syringes are most prone to the transmission of HIV . In Spain, 79% of HIV cases in 2010 were sexually.
In the case of sex, HIV transmission can occur for the following situations:
• For anal or vaginal sex acts (active or passive) with a high risk of infection.
• For fellatio in which the semen reaches the mouth (lowest risk).
Less than 1% of transmissions of HIV in 2010 occurred in childbirth because the HIV positive mother infected the child . This form of transmission is attached to a particular risk, because if appropriate prevention measures at birth the possibility that an HIV-positive mother passing the disease to the baby is 15 to 20% are not taken. Also the transplantation of organs from an HIV positive donor can infect the recipient. The risk of infection in patients requiring blood transfusion or blood product is very rare, because of the strict controls to which they are subjected.
Talk about a "transmission of AIDS" is wrong and wrong as it may appear as a result of HIV infection but does not why. What is transmitted is the pathogen (HIV) no disease ( AIDS ).
But what is really becoming infected with HIV? HIV transmission depends on various factors. Most have to do with the transferred pathogens: the more entering the body, the more likely to contract HIV. In addition, certain characteristics of the pathogen also play a role (known virulence, ie, the power to trigger a disease), as well as the health of the person to whom the virus is transmitted.
It is very difficult to determine exactly what the individual risk of HIV infection. Is only possible to establish statistical data. There are examples of people infected after a single contact risk, but it is also possible that repeated contacts with an HIV-infected (sex of years without protection, for example) do not have any consequences. From a statistical point of view and according to the route of transmission for 1000 risk contacts occur between one ten HIV infections. Transmission material also determines the possibility of transmission of HIV. HIV positive people tend to have the highest concentrations of virus in the blood , seminal fluid, vaginal secretion and on the surface of the intestinal mucosa. In the rest of the body fluid concentration of the virus is significantly lower HI and transmission while theoretically possible, is not yet determined if any. HIV is not transmitted by infection by airborne pathogens .
The incubation period of HIV infection , ie, the time from HIV infection until the outbreak of AIDS, is very different in each person and can range from several months to more than fifteen years. The duration of this phase also influenced by different factors such as medications, lifestyle, mental state and accompanying diseases. A "AIDS infection" as such does not exist: a HIV infection.