HIV Basics

HIV stands for:

H – Human
I – Immunodeficiency
V – Virus

HIV is a virus that weakens the immune system. It needs “host cells” to survive. The immune system is the body’s defense mechanism – including white blood cells – against diseases and infections. Cells are tiny containers of chemicals and water wrapped in a very thin layer of tissue. Cells are a basic building block in people and all living things.

It takes a while for the immune system to respond to the new virus. A person won’t test positive for HIV at first, but could still infect others.

HIV might not show any obvious symptoms right away. It can take years for someone to know what they’ve got. Early on, HIV can appear as a cough, fever, flu, stomachache, as pain in muscles and joints, or as swollen lymph glands. Another early symptom can be a skin rash lasting a couple of weeks. Women might also get a yeast infection.

25% of women estimated to be living with HIV in Ontario are still undiagnosed.1

The virus uses one kind of white blood cell to make copies of itself. It is called the CD4 T cell, and it gets damaged or killed by this process. With fewer and fewer CD4 T cells, the immune system gets weaker, because this kind of white blood cell helps to fight other infections and diseases. At a certain point, a person with HIV might have night sweats, diarrhea, fevers or swollen lymph nodes lasting for weeks.

A person who is infected with HIV is also described as being HIV positive.


What does it mean?

  • There is no cure for HIV, but it can be treated
  • HIV infections develop at different speeds
  • An HIV-positive woman can have a healthy life for many years
  • When HIV is passed between sexual partners or Injection Drug Users (IDUs) it is called horizontal transmission
  • When an HIV-positive mother passes the virus to her baby it is called vertical transmission
  • HIV is the virus that causes AIDS
  • AIDS is the end result of HIV infection

HIV infection is now considered to be an episodic disease that doesn’t go away. There is no cure, but with treatment, support and good care, women can live long, healthy and productive lives. A woman with HIV may have periods of relatively good health followed by serious illnesses.

AIDS stands for:

A – Acquired
I – Immuno
D – Deficiency
S – Syndrome


From HIV to AIDS

When an HIV-positive person’s immune system is seriously weakened, it can lead to one or more life-threatening opportunistic infections (OIs). It is at this point that HIV becomes AIDS. These kinds of infections are known as AIDS-defining illnesses. They are the result of a fragile immune system.

An HIV-positive person can also get an AIDS diagnosis based on a blood test of the CD4 cells. The test measures the number of these white cells per cubic millimetre of blood. This test is confidential. A count of less than 200 CD4 cells (or less than 14%) results in an AIDS diagnosis.

The usual count for people who do not have HIV/AIDS is between 500 and 1600 CD4 cells. It is normal for CD4 counts to fluctuate.

HIV becomes AIDS when:

  • An HIV-positive person’s CD4 T cell count goes down to 200 cells/mm3 or less
  • Someone with the virus develops an opportunistic infection – or AIDS-defining illness – which is unusual for those who do not have HIV to get

It is possible to recover from an AIDS diagnosis. Women can and do.

One of the benefits of a woman knowing her status is the ability to have treatment. Treatment can stop the virus from replicating and doing more damage to the immune system. The activity of the virus is measured by viral load. Having a low or undetectable viral load improves the health outcome for a woman. It also makes her less infectious.

For HIV testing locations in Toronto, please take a look at our SERVICE LOCATOR for sites that are close to you or your client.


More from Shared Health Exchange

1Care & Empowerment of Pregnant Women Living with HIV, Lindy Samson, MD FRCPC, 2010