What is human immunodeficiency virus (HIV)?

HIV is a virus that attacks and gradually weakens the immune system. HIV infects CD4+ cells, a type of white blood cell. White blood cells are an important part of the immune system, which helps you fight infections. As HIV-infected CD4+ cells are destroyed or impaired, the immune system becomes less able to fight infection and disease.
 

What causes HIV?

HIV infection is caused by a virus.

• HIV-1 causes almost all the cases of AIDS worldwide.
• HIV-2 causes an AIDS-like illness, but HIV-2 infection is uncommon in the United States.

How is HIV spread?

HIV is spread when blood, semen, or vaginal fluids from an infected person enter another person's body, usually through:

• Sexual contact. The virus may enter the body through a break in the lining of the rectum, vagina, urethra, or mouth. Worldwide, between 75% and 80% of all cases of HIV are transmitted by sexual contact.
• Infected blood. People who share needles, syringes, cookers, cotton, spoons, or eyedroppers used for injecting illegal drugs may inject HIV-infected blood into their veins. HIV can also be spread when people share needles to inject steroids or illegal drugs.

 
It is now rare in the United States for HIV to be transmitted by transfusions of infected blood or blood products. Blood donors are screened for risk factors. All donated blood is screened for HIV antibodies, and most blood products are heat-treated to kill any HIV virus that may be present.
 

How do I prevent HIV?

The only sure way to prevent sexually transmitted HIV to to avoid sex (including oral sex) before marriage. Once you are married, if you and your spouse are both faithful to each other and do not enter the marriage relationship with hiv it is unlikely you will acquire this disease (HIV can also be spread in various ways involving blood. For example needle sharing, etc.). Therefore saving sex until marriage and marrying a faithful partner who was not previously exposed to hiv is the only absolute way to avoid this sexually transmitted HIV.
 

What are the symptoms of HIV?

Symptoms of early HIV (acute retroviral syndrome), which are often mistaken for symptoms of another viral infection such as influenza or mononuclesosis, may include:

• Fever.
• Sore throat.
• Headache.
• Muscle aches and joint pain.
• Enlarged lymph nodes in the neck, armpits, and groin.
• Skin rash.
• Abdominal cramps, nausea, or vomiting.
• Diarrhea.

 
Early symptoms of HIV usually disappear on their own after 2 to 3 weeks.
 
After the initial infection with HIV, a person may go many years without any sign of illness. When symptoms do develop, they are often vague. Your health professional may suspect an HIV infection when symptoms persist for no other reason. Common symptoms include:

• Fatigue.
• Weight loss.
• Fever.
• Night sweats.
• Swollen lymph nodes in the neck, armpits, and groin.

How is HIV diagnosed?

HIV is diagnosed with blood tests. The diagnosis of HIV is made after two or more positive ELISA tests are confirmed by a positive Western blot assay.
 
A person is HIV-positive when antibodies to the virus are detected in his or her blood. It may take up to 6 months after the original infection for these antibodies to appear. An infected person can spread the virus to others during this time.
 

How is HIV treated?

If you are diagnosed with HIV infection during the initial symptoms of early HIV (acute retroviral syndrome), discuss the use of highly active antiretroviral therapy (HAART) with your health professional. Information about treatment of early HIV from clinical trails is very limited but suggests that treatment of early HIV with antiretroviral medications has a beneficial effect on CD4+ cell counts and viral load.
 
Treatment of established HIV with three or more antiretroviral medications (HAART) is based on:

• Your health and CD4+ counts (see table below).
• Your willingness and ability to follow your medication schedule as prescribed. This is essential for successful treatment of your HIV.

What increases my risk for HIV?

You have an increased risk of developing HIV if you:

• Are a bisexual or homosexual man.
• Have multiple sex partners, especially if either partner injects illegal drugs.
• Inject illegal drugs or steroids, especially if you share needles, syringes, cookers, or other equipment used to inject drugs.
• Have sex with someone who is a bisexual or homosexual man, has multiple sex partners, or uses injected illegal drugs or steroids.

What is acquired immunodeficiency syndrome (AIDS)?

AIDS is the last of several stages of infection with HIV. AIDS is diagnosed when you:

• Have a CD4+ cell count below 200 cells per microliter (µL) of blood.
• Develop an opportunistic disease or cancer.

 
More than half of adults with HIV who do not receive treatment develop AIDS within 12 or 13 years. Rapid progressors and young children develop AIDS within about 3 years if they do not receive treatment. Once the HIV progresses to AIDS, death often occurs within 18 to 24 months or sooner in these people.
 
**Some of above information provided via webmd.