HIV stands for human immunodeficiency virus. It is the virus that can lead to acquired immunodeficiency syndrome, or AIDS. Unlike some other viruses, the human body cannot get rid of HIV. That means that once you have HIV, you have it for life.

No safe and effective cure currently exists, but scientists are working hard to find one, and remain hopeful. Meanwhile, with proper medical care, HIV can be controlled. Treatment for HIV is often called antiretroviral therapy or ART. It can dramatically prolong the lives of many people infected with HIV and lower their chance of infecting others. Before the introduction of ART in the mid-1990s, people with HIV could progress to AIDS in just a few years. Today, someone diagnosed with HIV and treated before the disease is far advanced can have a nearly normal life expectancy.

HIV affects specific cells of the immune system, called CD4 cells, or T cells. Over time, HIV can destroy so many of these cells that the body can’t fight off infections and disease. When this happens, HIV infection leads to AIDS.

In 2012 an estimated 230,000 children in Sub-Saharan Africa were newly infected with HIV. However, nearly all of these infections can be prevented by comprehensive prevention of mother-to-child transmission (MTCT) services.

Only certain fluids—blood, semen (cum), pre-seminal fluid (pre-cum), rectal fluids, vaginal fluids, and breast milk—from an HIV-infected person can transmit HIV. These fluids must come in contact with a mucous membrane or damaged tissue or be directly injected into the bloodstream (from a needle or syringe) for transmission to possibly occur. Mucous membranes can be found inside the rectum, the vagina, the opening of the penis, and the mouth.

HIV may be spread by being born to an infected mother. HIV can be passed from mother to child during pregnancy, birth, or breastfeeding.

The most common HIV test is the antibody screening test, which tests for the antibodies that your body makes against HIV, not HIV itself. Antibody tests may be conducted in a lab or as a rapid test at the testing site. They may be performed on blood or oral fluid (not saliva).

Blood tests can detect HIV infection sooner after exposure than oral fluid tests because the level of antibody in blood is higher than it is in oral fluid. In addition, most blood-based lab tests find infection sooner after exposure than rapid HIV tests. Newer blood tests can find HIV as soon as 3 weeks after exposure to the virus.

In addition to antibody tests, there are several tests now in use that can detect both antibodies and antigens, which are pieces of the virus itself. Because these tests do not have to wait for the body to make an immune response to the virus, they can find infection earlier than tests that only look for antibodies.

Testing and treatment of sexually transmitted diseases (STDs) can be an effective tool in preventing the spread of HIV, the virus that causes AIDS. An understanding of the relationship between STDs and HIV infection can help in the development of effective HIV prevention programs for persons with high-risk sexual behaviors.

Individuals who are infected with STDs are at least two to five times more likely than uninfected individuals to acquire HIV infection if they are exposed to the virus through sexual contact. In addition, if an HIV-infected individual is also infected with another STD, that person is more likely to transmit HIV through sexual contact than other HIV-infected persons.