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FAQs
What is HIV?
HIV is short for Human Immunodeficiency Virus. HIV attacks the body's immune system and as the disease progresses it can make it hard to fight off infections. HIV particularly attacks the white blood cells called CD4 cells, which sets the immune system in motion when infections enter the body. HIV infects CD4 cells and uses their energy and nutrients to make new copies of HIV which go on to infect more cells. The lower a person's CD4 count, the weaker their immune system will be.
What is AIDS?
AIDS (Acquired Immune Deficiency Syndrome) is the result of damage to the immune system caused by HIV. A damaged immune system is unable to protect the body against certain specific ‘opportunistic’ infections and tumours. You must be HIV positive before you can develop AIDS.
There are four stages of HIV. The progression of, and affect it has on an individual depends on a number of factors, including; general health, lifestyle, diet, predisposition to the virus, etc. The progression of HIV from stage 1 to 4 can range from 2 years to 20 years. It is important to note that not everyone infected with HIV will develop AIDS, they are known as ‘long-term non-progressive’ HIV positive people. It is estimated that about 15% of people who are HIV positive fall into this category.
What are the stages of HIV?
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Infection
This occurs when a person becomes exposed to and infected with HIV. It may take some time after infection before a person will test positive for HIV, the average being 45 days but it can take up to 6 months or even longer for antibodies to be produced. Most people at this stage will not realise they have been infected. Some may have certain illnesses like a sore throat, a fever or a rash, or rarely a more severe illness, which is called sero-conversion illness.
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Asymptomatic
In this stage, which may last for many years, people will rarely show any outward signs of damage caused by HIV. Viral load tests have shown that HIV is actively replicating inside the bodies of asymptomatic people from the moment of infection onwards.
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Symptomatic
As the HIV replicates itself in the body it weakens and damages the immune system, this in turn leaves the person more susceptible to opportunistic infections and tumours. If people become ill because of these infections or tumours they are said to have symptomatic HIV infection.
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Acquired Immune Deficiency Syndrome (AIDS)
As there is no single test for AIDS, doctors look at a range of symptoms and tests before coming to a diagnosis. Doctors will look
for one of the opportunistic infections or cancers in the presence of underlying immune deficiency. |
What are Opportunistic Infections and Tumours?
Opportunistic Infections and Tumours are called opportunistic because they are caused by organisms which are normally controlled by the immune system but which ‘take the opportunity’ to cause disease if the immune system has been damaged.
What is a HIV Test?
HIV antibody testing usually refers to the tests that determines whether or not you are infected with HIV. These tests look for "antibodies" to HIV. (Antibodies are proteins produced by the immune system to fight a specific germ).
Other HIV tests are used when people already know that they are infected with HIV. These measure how quickly the virus is multiplying (a viral load test,) or the health of your immune system (a CD4 count,). The most common HIV test is a blood test.
What is Viral Load?
This refers to the amount of HIV circulating in the blood plasma (the fluid between the blood cells).
What is a CD4 Count?
CD4 cells are a type of lymphocyte (white blood cell) that co-ordinate the immune system’s response to certain micro-organisms such as viruses. On entering the body HIV attacks these cells and uses them
to replicate itself. A CD4 count is used to show the progression of HIV infection, and the level of damage to the immune system. An average CD4 count in a person who is HIV-negative ranges between 400 and 1600 per cubic mm of blood.
When do you test after potential exposure to HIV?
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Incubation Period
If you become infected with HIV, it usually takes between two and three months for your immune system to produce antibodies to HIV. About 5% of people take longer than two months so a confirming test six months after exposure is important.
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Antibody test
Antibody test results for HIV are thought accurate more than 99.5% of the time. Before results are given to a patient, the test has usually been done two or more times. The first test uses enzymes to test for HIV antibodies. This test is called an "EIA" or "ELISA" test. Before a positive ELISA test result is reported, it is confirmed by another test called a "Western Blot." |
How is HIV transmitted?
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Unprotected sexual intercourse (either vaginal or anal) with someone who is HIV positive. Women are at greater risk of HIV infection through vaginal sex than men, although the virus can also be transmitted from women to men. Anal sex poses a high risk mainly to the receptive partner, because the lining of the anus and rectum are extremely thin and filled with small blood vessels that can be easily injured during intercourse. There is a lesser but potential risk facilitated by fingers, fists or sex toys.
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Unprotected oral sex with someone who is HIV positive. There are far fewer cases of HIV transmission attributed to oral sex than to either vaginal or anal intercourse, but oral-genital contact poses a clear risk of HIV infection, particularly when ejaculation occurs in the mouth (some estimates are between 1 and 3 % of overall transmissions).
This risk is increased when either partner has cuts or sores, such as those caused by sexually transmitted diseases (STDs), or recent tooth brushing (bleeding gums) which can allow the virus to enter the bloodstream.
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Blood to blood contact. This mainly happens through the sharing of injecting equipment or related paraphernalia among injecting drug users. In the past, before screening this also occurred through blood transfusions or from infected blood products. Very rarely it can happen through occupational accidents amongst healthcare workers, such as needle-stick injuries. Fortunately, follow up studies have shown that less than 1% of individuals who receive injuries with HIV contaminated needles become infected.
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Vertically, from an HIV positive woman to her baby during the course of pregnancy, birth or breast-feeding. Mother-to-infant transmission has been reduced, where pregnant women are tested for HIV and those who test positive are provided with drugs to prevent transmission and counselled not to breast feed. |
NB
For HIV transmission to take place there are 3 essential factors which need to be in place. This is known as the chain of transmission.
1. Route of Transmission - the virus must get from the body of an infected person into the body of another person.
2. Quality - the HIV is a very weak virus so it can be damaged very easily once it leaves the body. The virus can be damaged in three known ways: exposure to air, bleach or temperatures above 60 degrees. If the virus is damaged by some of these factors transmission may not take place.
3. Quantity - only blood, semen, vaginal fluids, and breast milk have sufficient quantity of HIV present to transmit the virus. Although the virus is present in other bodily fluids of infected people (e.g. saliva), the level of the virus in these fluids is far too low to be infectious.
Is there treatment available for HIV?
Since 1987, people in developed countries have access to a number of drugs to treat HIV infection and AIDS. Some of these drugs are designed to treat the opportunistic infections/tumours. In addition, several other types of drugs seek to prevent HIV from reproducing
and destroying the body’s immune system.
As HIV is made up of RNA genetic material it needs to become DNA genetic material to reproduce. These anti viral drugs block two HIV enzymes called reverse transcriptase (RT) and protease from changing the genetic make up of HIV, in order to reproduce itself in the human body. In addition a new anti-viral drug prevents the HIV attaching to human DNA.
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Reverse transcriptase inhibitors
(RTI) attack a HIV enzyme called reverse transcriptase. Once HIV has locked onto and invaded a human cell, it uses a substance called reverse transcriptase to convert its genetic code into the same form as the genetic code of human cells (DNA). This viral DNA then merges with human DNA, converting the cell into a factory for building blocks of the virus.
RTI’s medications include: ABACAVIR, DELAVIRDINE, DIDANOSINE (DDI), EFAVIRENZ, LAMIVUDINE (3TC), NEVIRAPINE, STAVUDINE (D4T), ZALCITABINE (DDC) AND ZIDOVUDINE (AZT).
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Protease inhibitors (PI’s) attack the HIV enzyme protease. Protease
is a different HIV enzyme. After HIV has successfully merged its DNA with human cells DNA, the cell produces a string of protein. Protease cuts this protein into smaller proteins that can be used to construct
new particles. By blocking protease, PI’s help to prevent an infected cell from producing new infectious virus particles.
PI’s medications include: INDINAVIR (CRIXIVAN), AND RITONOVIR (NORVIR).
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Fusion Inhibitors are the first of a new class of anti-HIV drugs known as entry inhibitors, in essence they prevent HIV from entering the CD4 cells. Medication used: T-20
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Other treatment options: Several other types of treatment options are being studied, including tenofovir (a nucleotide analogue), HYDROXUREA (a ribonucleotide inhibitor) and a number of immune therapies such as INTERLEUKIN-2 and REMUNE aim to encourage an immune response against HIV. |
Many HIV patients are taking several of these drugs in combination
– a regimen known as Highly Active Antiretroviral Treatment (HAART). When successful, such combination or “cocktail” therapy can reduce
the level of HIV in the bloodstream (viral load) to very low or even undetectable levels, which can sometimes enable the body’s CD4 immune cells to rebound to normal levels. However, it must be noted that a person whose HIV levels are undetectable can still infect another person.
With the introduction of new treatments for HIV, many people are living healthier lives for longer
periods of time. It is important to highlight that not everyone responds well to treatment and the side effects for some can be difficult to endure. |
