Hiv

What is HIV?

HIV is the human immunodeficiency virus that causes AIDS. HIV infects human cells and uses the energy and nutrients provided by those cells to grow and reproduce.

What is AIDS?

AIDS (acquired immunodeficiency syndrome) is a disease in which the body's immune system breaks down and is unable to fight off certain infections. When a person is infected with HIV, the virus enters the body and lives and multiplies primarily in the white blood cells. These are the immune cells that normally protect us from disease.

How quickly do people infected with HIV develop AIDS?

Most people remain without obvious symptoms for 10 to 12 years and a few for much longer. As with most diseases, early medical care can help prolong a person's life.

How many people are affected by HIV/AIDS?

It is estimated that there are now over 40 million people living with HIV or AIDS worldwide. Most of them do not know they carry HIV and may be spreading the virus to others. Here in the U.S., nearly one million people have HIV infection or AIDS, or roughly one out of every 250 people. At least 40,000 Americans become newly infected with HIV each year, and it is estimated that half of all people with HIV in the U.S. have not been tested and do not know they are carrying the virus. Since the beginning of the epidemic, AIDS has killed more than 30 million people worldwide, including more than 500,000 Americans. AIDS has replaced malaria and tuberculosis as the world's deadliest infectious disease among adults and is the fourth leading cause of death worldwide. Over 13 million children have been orphaned by the epidemic.

How is HIV transmitted?

A person who is HIV-infected carries the virus in certain body fluids, including blood, semen, vaginal secretions, and breast milk. The virus can be transmitted only if such HIV-infected fluids enter the bloodstream of another person. This kind of direct entry can occur (1) through the linings of the vagina, rectum, mouth, and the opening at the tip of the penis; (2) through intravenous injection with a syringe; or (3) through a break in the skin, such as a cut or sore. Usually, HIV is transmitted through:

* Unprotected sexual intercourse (either vaginal or anal) with someone who is HIV infected.

In western countries, women are four times more likely to contract HIV through vaginal sex with infected males than vice versa. Women are at greater risk of HIV infection through vaginal sex than men, although the virus can also be transmitted from women to men. Anal sex (whether male-male or male-female) poses a high risk mainly to the receptive partner, because the lining of the anus and rectum are extremely thin and filled with small blood vessels that can be easily injured during intercourse.

* Unprotected oral sex with someone who is HIV infected.

* Sharing needles or syringes with someone who is HIV infected.

Laboratory studies show that infectious HIV can survive in used needles for a month or more. That is why people who inject drugs should never reuse or share syringes, water, or drug preparation equipment. Other types of needles, such as those used for body piercing and tattoos, can also carry HIV.

* Infection during pregnancy, childbirth, or breast-feeding (mother-to-infant transmission).

How is HIV not transmitted?

HIV is not an easy virus to pass from one person to another. It is not transmitted through food or air (for instance, by coughing or sneezing). There has never been a case where a person was infected by a household member, relative, co-worker, or friend through casual or everyday contact such as sharing eating utensils and bathroom facilities, or hugging and kissing. You cannot get HIV from giving blood at a blood bank. Sweat, tears, vomit, feces, and urine do contain HIV, but have not been reported to transmit the disease (apart from two cases involving transmission from feces via cut skin). Mosquitos, fleas, and other insects do not transmit HIV.

How can I reduce my risk of becoming infected with HIV?

If you are sexually active, protect yourself from HIV infection by practicing safer sex. Whenever you have sex, use a condom. Do not share syringes or other injection equipment with anyone else.

Is there a link between HIV and other STIs?

Having a sexually transmitted infection can increase your risk of acquiring and transmitting HIV. This is true whether you have open sores or breaks in the skin. Where there are breaks in the skin, HIV can enter and exit the body more easily. STIs can cause biological changes that may make HIV transmission more likely. Studies show that HIV-infected individuals who are infected with another STI are three to five times more likely to contract or transmit the virus through sexual contact.

Are some people at greater risk of HIV