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Human immunodeficiency virusHIV (Human Immunodeficiency Virus) is a virus that attacks the immune system. It is spread through contact with infected blood, semen or vaginal fluids. There is no cure for HIV, but antiretroviral medication can reduce the amount of virus in the body and help you to stay healthy. Without treatment, HIV infection can progress to AIDS (Acquired Immunodeficiency Syndrome).

Information for Health Professionals

HIV (Human Immunodeficiency Virus) is a virus that attacks the immune system, the body’s natural defense system. Without a strong immune system, the body has trouble fighting off disease. Both the virus and the infection it causes are called HIV.

White blood cells are an important part of the immune system. HIV invades and destroys certain white blood cells called CD4+ cells. If too many CD4+ cells are destroyed, the body can no longer defend itself against infection.

Without treatment, HIV infection progresses and when advanced, AIDS (Acquired Immunodeficiency Syndrome) can develop. People with AIDS have a low number of CD4+ cells and get infections or cancers that rarely occur in healthy people.

Having HIV does not mean you have AIDS. Even without treatment, it takes a long time for HIV to progress to AIDS—usually 10 to 12 years. If HIV is diagnosed before it becomes AIDS, medicines can slow or stop the damage to the immune system and AIDS may not develop. With treatment, many people with HIV live long and active lives.

HIV is found in semen, blood, breast milk, vaginal and anal fluids. Most people get HIV by having unprotected vaginal or anal sex with someone who has HIV. In some cases, HIV may be passed during unprotected oral sex.

HIV can be passed when sharing drug equipment, such as syringes, with someone who has HIV. The virus can also be passed from a mother to her baby during pregnancy, birth, or breast-feeding. Medications can be taken during pregnancy to prevent the virus from being passed to the baby.

HIV doesn't survive well outside the body. It cannot be spread by casual contact such as kissing or sharing drinking glasses with an infected person.


HIV may not cause symptoms early on. People who do have symptoms may mistake them for the flu or mono. Common early symptoms include:

  • Fever.
  • Sore throat.
  • Headache.
  • Muscle aches and joint pain.
  • Swollen glands (swollen lymph nodes).
  • Skin rash.

Symptoms may appear from a few days to several weeks after a person is first infected. These early symptoms usually go away within 2 to 3 weeks.

After the early symptoms go away, an infected person may not have symptoms again for many years. 

Treatment usually keeps the virus under control and helps the immune system stay healthy. But without treatment, the virus continues to grow in the body and attacks the immune system. After a certain point, symptoms reappear and then remain. These symptoms usually include:

  • Swollen lymph nodes.
  • Extreme tiredness.
  • Weight loss.
  • Fever.
  • Night sweats.

A doctor may suspect HIV if these symptoms last and no other cause can be found.


Without treatment, HIV infection can progress to AIDS. AIDS is the collection of symptoms, signs, and effects that occur once a person's immune system has been substantially weakened by HIV infection.

The diagnosis of AIDS is based on a person with HIV contracting a disease that is listed as an "AIDS-defining" disease. For a person with an immune system that is weakened by HIV, these diseases are very serious and can be life-threatening.

On average, without treatment, it takes more than 10 years to progress to this late stage of HIV infection. In addition to the impact of taking antiretroviral therapy, the progression of HIV infection depends on other factors, including the health and lifestyle of the person and the strength of his or her immune system.


The only way to know for sure if you have HIV is to get a blood test. It usually takes 1 - 2 weeks for test results to come back from the laboratory. There are 2 common types of tests for HIV that are performed in British Columbia.

The first type of test is called an antibody test. If you have been exposed to HIV, your immune system will make antibodies to try to destroy the virus. The two primary blood tests used to detect HIV antibodies are called the ELISA and the Western Blot assay. If the first ELISA is positive, the blood sample is tested again. If the second ELISA test is positive, the lab will do a Western Blot to confirm.

The second type of test is called a nucleic acid amplification (NAAT) test. This test detects genetic material belonging to the HIV virus (DNA and RNA) in the blood. If viral RNA is detected but antibody tests are negative or unclear, it means that the person may be in the acute or very early stages of HIV infection.

The time it takes for a new HIV infection to show up in a blood test is called the "window period". During this time the infection is not yet detectable but can still be passed on to other people. The window period for the antibody test ranges from 4 - 6 weeks up to 3 months, as it takes this long for HIV antibodies to reach a detectable level in the body.

HIV testing is done in most doctors’ offices, public health units, hospitals, and clinics.

Some doctors and clinics in British Columbia now also use a Point of Care HIV test. This is an ELISA (antibody) test that can be performed in the office or clinic, and the results are ready in about 15 minutes. However, these results are preliminary only - any positive tests must be confirmed with a Western Blot test performed at the provincial laboratory.

If you think you have been exposed to HIV but you test negative for it:

  • another HIV test can be performed 2 - 3 weeks after possible exposure.
  • meanwhile, take steps to prevent the spread of the virus.

The standard treatment for HIV is a combination of medicines called highly active antiretroviral therapy (HAART). Antiretroviral medicines slow the rate at which the virus multiplies. Taking this medication can reduce the amount of virus in your body and help you to stay healthy.

Treatment has become much easier to follow over the past few years. New combination medicines include two or three different medicines in one pill. Many people with HIV get the treatment they need by taking just one or two pills a day.

If you have no symptoms and your CD4+ cell count is at a healthy level, you may not need treatment yet. There are pros and cons to taking HAART before you have symptoms. Discuss these with your doctor so you understand your choices.


When people first find out they are HIV positive, they feel as if it is the most difficult news they have ever heard. They don't know what to do or who to tell.

If you have just been diagnosed with HIV, you may want to speak to one or two close friends that you can trust. Many people also say that talking to another person who is HIV positive is very helpful.


HIV can be spread by people who don't know they are infected. To protect yourself and others:

  • Practice safe sex. Use condoms when you have sex until you are sure that you and your partner do not have HIV.
  • If you have a new sexual partner, get tested together and retested 3 months later. Use condoms in the meantime.
  • Talk to your partner or partners about their sexual history and your own sexual history.
  • If you do have sex with someone who has HIV, it is important to practice safe sex and to be regularly tested for HIV.
  • If you use drugs, do not share intravenous (IV) needles, syringes, cookers, cotton, cocaine spoons, or eyedroppers with others.

Test regularly for sexually transmitted infections. Having an STI such as gonorrheachlamydia or syphilis increases your risk of contracting HIV.

If you are pregnant and have tested positive for HIV, the risk of spreading HIV to your baby can be greatly reduced if:

  • You are on medication that reduces the amount of virus (HIV RNA) to undetectable levels during pregnancy.
  • You receive zidovudine (ZDV) before your baby is born.
  • You do not breastfeed your baby.
  • Your baby also receives HIV treatment after it is born.
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