HIV stands for Human Immunodeficiency Virus. It is the virus that causes AIDS. AIDS stands for Acquired Immune Deficiency Syndrome. HIV can be transmitted through the blood, sexual fluids, or breast milk of an HIV-infected person.
Over time, infection with HIV can weaken the immune system to the point that the system has difficulty fighting off certain infections. These types of infections are known as opportunistic infections. These infections are usually controlled by a healthy immune system, but they can cause problems or even be life-threatening in someone with AIDS.
A blood test can determine if a person is infected with HIV. Too many people don’t know they have HIV. In the United States, nearly 1.1 million people are living with HIV, and almost one in five don’t know they are infected. Getting tested is the first step to finding out if you have HIV. If you have HIV, getting medical care and taking medicines regularly helps you live a longer, healthier life and also lowers the chances of passing HIV on to others.
If a person tests positive for HIV, it does not necessarily mean that the person has AIDS. A diagnosis of AIDS is made by a physician according to the CDC AIDS Case Definition. A person infected with HIV may receive an AIDS diagnosis after developing one of the CDC-defined AIDS indicator illnesses. A person with HIV can also receive an AIDS diagnosis on the basis of certain blood tests (CD4 counts) and may not have experienced any serious illnesses.
Where did HIV come from?
There are many theories about the origin of HIV. The first known case was found in a blood sample collected from man from Kinshasha, Democratic Republic of Congo in 1959. Genetic analysis of this blood suggests that the origin of HIV came from a single strain of HIV-1 in the 1940s or 1950s. In the U.S. the virus is known to have existed since the mid 1970s. Symptoms of rare types of what are now known as opportunistic infections began manifesting themselves between 1979-1981. HIV was first isolated by scientists in 1983. The virus was at first called HTLV-III/LAV (human T-cell lymphotropic virus-type III/lymphadenopathy- associated virus) by an international scientific committee. This name was later changed to HIV (human immunodeficiency virus).
What is AIDS?
A diagnosis of AIDS (acquired immune deficiency syndrome) is made by a physician. An HIV-infected person may be diagnosed with AIDS if he or she meets certain clinical criteria. Criteria include becoming sick with an illness defined by the Centers for Disease Control and Prevention (CDC) as an AIDS-indicator illness (illnesses that take advantage of the body’s weakened immune system) and/or by taking a blood test that shows that the person’s immune system is severely damaged.
What are the symptoms of HIV?
Most people infected with HIV do not know that they have become infected, because they do not feel ill immediately after infection. However, some people do experience a illness with fever, rash, joint pains and enlarged lymph nodes. If an immune reaction to HIV occurs, it usually takes place between 1 and 6 weeks after HIV infection has happened. A person with HIV may look healthy and feel good, but they can still pass the virus to you, especially during the initial infection period. You cannot tell if someone has HIV by just looking at them. The only way to determine whether HIV is present in a person’s body is by testing.
How does HIV become AIDS?
AIDS is a disease caused by HIV. HIV infects cells of the human immune system and destroys or impairs their function. Infection with this virus leads to slow destruction of a persons’ immune system making them more susceptible to many kinds of infections. Once a person with HIV develops any one of a number of rare infections or cancers – tuberculosis, pneumonia, candidiases or tumors – they are said to have AIDS. This most often occurs 10-15 years after a person becomes infected with HIV.
How long does it take for HIV to cause AIDS?
According to the Centers for Disease Control and Prevention (CDC), prior to 1996, scientists estimated that about half the people with HIV would develop AIDS within 10 years after becoming infected. This time varied greatly from person to person and depended on many factors, including a person’s health status and their health-related behaviors.
Since 1996, the introduction of powerful anti-retroviral therapies has dramatically changed the progression time between HIV infection and the development of AIDS. There are also other medical treatments that can prevent or cure some of the illnesses associated with AIDS, though the treatments do not cure AIDS itself. Because of these advances in drug therapies and other medical treatments, estimates of how many people will develop AIDS and how soon are being recalculated, revised, or are currently under study.
How common are HIV and AIDS?
According to the Centers for Disease Control and Prevention (CDC), approximately 1 million persons in the United States are living with diagnosed or undiagnosed HIV/AIDS. CDC estimates there are over 41,000 new HIV infections in the United States each year.
The Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates that, since the beginning of the epidemic, almost 60 million people worldwide have been infected with HIV and 25 million people have died of HIV-related causes. UNAIDS estimates that about 33.4 million people worldwide were living with HIV in 2008.
Who does HIV affect?
There are various risk factors that make some people more at risk for contracting HIV than others. Most people, however, run some risk of contracting HIV as they share in one or more of the following risk factors:
- Unprotected vaginal, anal, or oral sex
- Early age of first sexual activity—It is common for youth to engage in sexual activity before receiving information about HIV prevention
- Heterosexual sex–Women and minorities are particularly vulnerable to HIV infection
- Men who have Sex with Men (MSM)–Stigma and discrimination make it more difficult for MSM to access testing and counseling services
- Sexually transmitted infection (STIs)–The presence of other STIs can greatly increase the likelihood of HIV transmission
- Unprotected vaginal, anal, or oral sex
- Exchange sex for money
- Substance abuse—Chronic and intermittent substance users are more likely to engage in high-risk behaviors while using. Injection drug users also run the risk of being infected by HIV while sharing unclean needles.
- Poverty—Socioeconomic factors can directly and indirectly influence a person’s vulnerability to HIV infection. For many people poverty prevents access to quality health care.
- Out-of-school youth—Those that drop out of school are more likely to become sexually active younger and less likely to use condoms and other types of contraception.
- Lack of awareness—Many people, particularly youth, don’t recognize the ways in which they are vulnerable to HIV infection, making them more likely to behave in ways that put them at risk.
How safe is the U.S. blood supply?
The U.S. blood supply is one of the safest in the world. Infection through blood transfusion and other blood products is rare. Since 1985, the blood supply has been ELISA tested for HIV. According to the CDC, an estimated 1 in 450,000 to 1 in 660,000 donations per year are infectious for HIV but are not detected by current antibody screening tests. In 1995, blood banks also began testing with P24 tests along with ELISA, to detect infection with HIV during this window period. As technology advances, the blood supply will become even safer.
How is HIV transmitted?
HIV can be transmitted through the blood, sexual fluids (semen, preseminal fluid, or vaginal fluid) or breast milk of an HIV-infected person. People can get HIV one of these fluids enters the body by way of the mucous membranes (the soft, moist skin found in any opening of the body) or the bloodstream. The virus can be passed during unprotected vaginal, anal or oral sex with a HIV-infected person. An HIV-infected mother can transmit HIV to her infant during pregnancy, delivery or while breastfeeding. People can also become infected with HIV when using injection drugs through sharing needles and other equipment (or works) including cookers and cottons with someone who is infected.
The risk of transmission varies with the type of exposure (e.g. sexual, needle sharing, etc.) The Centers for Disease Control and Prevention offers a table quantifying the this HIV transmission risk that comes from different types of exposures. See the table and explanation at the CDC website.
How effective are latex condoms at preventing HIV?
Studies have been done to test how well latex condoms work for preventing HIV transmission. This research has shown that latex condoms are highly effective at protecting a person from transmitting or becoming infected with the virus. The studies were done on HIV-negative individuals at high-risk for the disease because there partners were HIV-positive. Latex condoms used consistently and correctly were effective 98-100% of the time.
While not having sex or to having sex with a long-term mutually monogamous partner who is not infected with HIV or other sexually transmitted infections (STIs) is the only way to protect yourself completely, latex condoms used consistently and correctly are highly effective in preventing HIV and many other STIs.
Can I get HIV from casual contact?
HIV is not transmitted by day-to-day contact in social settings, schools or in the workplace. You cannot be infected by shaking someone’s hand, by hugging someone, by using the same toilet or drinking from the same glass as an HIV-positive person, playing sports with or by being exposed to coughing or sneezing by anyone living with HIV. There is no evidence that HIV is spread through kissing. So you should not be fearful of interacting with persons who are living with the disease.