What is HIV?
HIV stands for Human Immunodeficiency Virus and is the virus that causes Aids.
How does HIV work?
Your immune system is your body’s natural defence against infection and illness. Part of our immune system is made up of white blood cells, some of which are called CD4 cells. The CD4 cells act as soldiers to defend our bodies against germs that make us sick. HIV weakens our immune system so that we get sick more often and it becomes harder to recover.
Once HIV infects the immune system, it makes millions of copies of itself, using mainly the body’s CD4 cells (soldier cells). As the HIV continues to multiply, the CD4 cells respond by producing antibodies to try to fight the HIV. But the immune system eventually becomes tired and weak as more and more CD4 cells are destroyed. The immune system eventually becomes so weak that it is no longer able to fight off illness and disease.
If you catch a cold or flu, within a few days your immune system learns how to fight the particular virus that you’ve been infected with and you are able to recover. HIV is different from other viruses like a cold or the flu, because it specifically attacks the cells that are responsible for keeping the body healthy — CD4 cells.
When do you know you have HIV?
You only know you have HIV when you take an HIV-test and the result confirms that you are positive. When you’re first infected, you may not know it because there are generally no visible signs and symptoms. You can live with HIV for a long time without knowing you are infected; and this is why HIV is spread easily.
Glossary of Terms
- Aids: Aids stands for Acquired Immune Deficiency Syndrome and is the set of symptoms and diseases that result from advanced HIV infection.
- CD4 cells: CD4 cells are specialised white blood cells (soldier cells) that play an important role in the body’s immune system.
- Antibodies: Antibodies are what your body produces when it identifies a germ or virus.
CD4 count: CD4 cells are a type of white blood cell that we all have in our bodies. By counting how many CD4 cells we have in our bodies, we can tell how healthy our immune systems are.
What is Aids?
In South Africa, a person is classified as having Aids if they have had a positive HIV antibody test, as well as a CD4 count less than 200/mm3 and are diagnosed with one or more Aids-defining illnesses. But the next stage from here is not always death. Many people have shown that if they receive antiretroviral (ARV) therapy at this stage, they have the ability to move back to earlier phases of the disease, becoming healthier.
HIV will progress at different rates in different people. Most people can live for many years before they develop Aids. Once an individual has been diagnosed with Aids, their risk of dying from an opportunistic infection is very high; an example of one of the most common opportunistic infections is TB. Therefore, identifying HIV infection as early as possible maximises a person’s chance of survival.
When do you know you have Aids?
The World Health Organisation (WHO) defines Aids in adults if a person demonstrates all of the following criteria:
- Has a positive HIV test result for the HIV antibody;
- When the number of their CD4 cells (soldier cells) is less than 200/mm3 as a result of HIV infection (this is measured by a CD4 count blood test); and
- If a person has certain infections that are not common in people with healthy immune systems (who are not HIV-positive). These illnesses are called Aids-defining illnesses — such as types of skin and other cancers (Kaposi’s sarcoma), types of pneumonia (PCP), types of bacterial infections, wasting syndrome (weight loss), cryptococcal meningitis and candida.
Not everyone who is living with HIV has Aids. It may take years for a person living with HIV to develop Aids. It depends on the individual’s body and if they start ARV treatment at the right time.
There is no cure or preventative vaccine for HIV, but with ARV treatment, you can live a normal life.
According to the South African National HIV Prevalence Survey 2008 on the South African Aids epidemic, approximately 5.21-million South Africans are living with HIV.
When people refer to the “window period”, they are actually talking about the time from becoming infected up until the HIV antibodies can be picked up by an HIV antibody test.
Glossary of Terms
- Opportunistic infections: are illnesses that occur in people whose immune systems have been weakened.
- Aids-defining illnesses: are classified as certain illnesses that can be common in people who are living with HIV, whose immune systems are weak.