By now there are probably a lot of numbers, letters, and tests you have heard about during your years at SickKids. You may feel like you have some knowledge about HIV or you may not. Either way, as you get ready for your transition to adult care it is important for you to have a good understanding of this information. Here are some of the key points you should start learning more about.
If you need a refresher, here is a list of common terms, abbreviations, tests, and issues you often hear discussed in relation to HIV.
Just what is HIV?
- HIV is the acronym (short form) for Human Immunodeficiency Virus, a virus which attacks and weakens the body’s immune system.
- The immune system is able to kill most germs (viruses, bacteria,) that infect the body.
- In people who have HIV, the cells being attacked are part of the immune system.
- Without a strong immune system, the body is unable to fight off other infections.
What is AIDS?
- “AIDS” is a bit of an outdated term
- AIDS (Acquired Immunodeficiency Syndrome) is a term used for an HIV positive person whose immune system has been damaged so severely that the person is susceptible to, or has had, “opportunistic infections”.
- The immune system of persons with AIDS can recover with treatment allowing that person to continue to live a healthy life
How is HIV transmitted?
- If you are a woman and you have a child, HIV can be transmitted during pregnancy, birth, or through breast milk
- Unprotected anal, vaginal, or oral sex
- Contact with HIV positive blood
- Sharing needles or syringes (e.g. tattoo needles, body piercing or injection drugs)
What does viral load mean?
- Viral load measures how much of the virus is in your blood.
- The higher the viral load, the more virus
- Viral load is measured in copies of virus per millilitre of blood (cpm) . It can be so low that the test does not detect it (<40 cpm) or it can go as high as 1, 000,000 cpm.
- Measuring your viral load is used to see how well your antiretroviral therapy is working.
- It is important to know that even when the viral load is so low the test cannot detect it you are still HIV positive and you can still transmit the virus to others.
What is a CD4 count?
- CD4+ cells are part of the immune system. They are called CD4+ because CD4 is the name of an important protein these cells have, like a flag, on the their surface.
- When an ‘invader’, like a virus or bacteria, enters the body the CD4+ cells are activated to help fight off the infection.
- When HIV enters the body, it attaches to the CD4 flags and enters the cell where it is protected from the immune system.
- The CD4+ cells that HIV has invaded are destroyed when the virus replicates within them. Once the CD4 cell is destroyed, the new HIV viruses made in that cell are released and can infect other CD4 cells.
- Measuring the number of CD4 cells (CD4 count) in blood tells us how well the body’s immune system is working. A CD4 count above 500 x106/L is considered normal in adults and children >5 yrs.;≥1,000 x 106/L in children 1-5 yrs and ≥1,500 x 106/L in children <12mos)
- Risk of opportunistic infections is greatest when the CD4 counts is ≤200
What are Opportunistic Infections?
- Opportunistic Infections (OI’s) are infections caused by viruses, bacteria, yeast and other pathogens (germs) that cause serious disease in a persona with a weakened immune system.
- Two examples of opportunistic infections are Pneumocystis pneumonia and esophageal candidiasis.
What is Antiretroviral Therapy?
- Antiretroviral drugs are a group of medications used to treat HIV. Sometimes these medications are referred to as ARVs. Antiretroviral therapy can be referred to as ART.
- When three or more ARVs are used in combination, this is called Highly Active Antiretroviral Therapy or ‘HAART’. Some people also refer to this as cART, or “combination antiviral therapy”.
For more information on medications have a look at the Medications.
Take the How much do you know about HIV quiz