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HIV and AIDS
Part 1 - General Questions
What is HIV?
HIV is a virus which can cause an incurable and life threatening medical condition called AIDS. HIV stands for the Human Immunodeficiency Virus. Over time, this virus attacks the body’s natural defence against diseases (the immune system), which makes a person vulnerable to certain infections and malignancies.
There are two types of HIV.
- HIV-1 is the main form found around the world.
- HIV-2 is found mainly in parts of West Africa.
What is AIDS?
AIDS is a medical diagnosis caused by long term HIV infection. AIDS stands for Acquired Immune Deficiency Syndrome. Someone has AIDS when their immune system has been damaged so badly by HIV that they are unable to fight off a wide range of illnesses that people without an immune related illness, such as HIV, would normally be able to cope with.
It may take years for signs and symptoms of AIDS to occur. Most AIDS defining illnesses can be treated or prevented with medication. With current medications, many people living with HIV/AIDS remain well for many years and do not need hospitalisation.
How does HIV cause illness?
HIV causes illness by damaging the immune system through infecting the immune system’s helper cells. The immune system is the body’s natural defence mechanism against infection. An important part of this system is a group of white blood cells called lymphocytes. Lymphocytes can be further divided into various subgroups which each perform specific tasks. T4 cells, also called CD4 cells, are a type of lymphocyte that recognise anything foreign and activate the immune system to protect the body.
When HIV enters the bloodstream, it infects and destroys these T helper cells. By doing this, it causes a gradual destruction of parts of the immune system. Eventually, the body becomes vulnerable to other infections.
What type of virus is HIV?
HIV is a retrovirus. Most viruses infect cells and reproduce in the main body of the cell simply by inserting their genetic material (DNA) into the cell’s reproductive machinery. However, a retrovirus has a different type of genetic material (RNA), which needs an enzyme called reverse transcriptase to change the RNA to DNA before taking over the cell’s reproductive machinery. This turns the cell into a virus factory, reproducing copies of HIV rather than new, healthy cells.
HIV is also different from most viruses as is specialises in attacking the very cells that are the body’s defence against viruses – the immune system.
Where did HIV originate?
It is generally agreed that Simian Immunodeficiency Virus (SIV) found in African chimpanzees and monkeys became both forms of Human Immunodeficiency Virus (HIV) in humans (HIV-1 and HIV-2), but exactly how and when this occurred is disputed, although the leading theory is that SIV was transferred to hunters who were infected while butchering monkeys for food.
What are the symptoms of becoming HIV positive?
It can be difficult to diagnose HIV infection, as your body’s response to HIV infection is the same as for any other viral infection. There are no specific symptoms that will tell you that you have been infected with HIV and not everyone who is infected with HIV experiences symptoms, some only mild symptoms and only a small number experience severe symptoms.
However, a few weeks following infection with HIV, some people have a severe “flu-like” illness with fever, rash and swollen lymph nodes (the “seroconversion illness”). During this time the virus spreads rapidly through the body. An HIV test preformed at this time may not show up the virus. It can take several weeks or months for the test to become positive – this is called “the window period”.
It is important to note that anxiety and stress can also cause similar symptoms.
The only way to know if you have become infected with HIV or not is to have a specific blood test after allowing for the window period.
If you have been involved in any high risk activities, such as unsafe sex, and have concerns about possible recent HIV infection, you should consult a GP or a sexual health clinic and consider being tested for all STIs too.
What is the incubation period of the virus? (This is not the same as the window period.)
This is the period of time it takes from becoming infected with HIV to developing symptoms of disease or illness. This period varies from person to person, but without treatment, the average time period is considered to be around 7-10 years. This period may also vary due to interventions with anti-retroviral medications. During this time there may be no outward evidence of illness, but the virus remains active (replicating and mutating) in the body, can still be detected by a blood test and the person is infectious.
This information was taken from a booklet created by the NSW HIV/AIDS Information Line |
