Definition
The Human Immunodeficiency Virus (HIV) is a retrovirus (a virus which uses the body's own cells to reproduce itself) that attacks the human body's immune system and causes the Acquired Immune Deficiency Syndrome (AIDS).
Budding virus: The virus that causes AIDS is shown budding out of a human immune cell, which the virus infects and uses to replicate. NIH. Enlarge image.
Origins: The origins of HIV are unclear. Luc Montagnier and Robert Gallo discovered the virus in 1983-84 and identified HIV as the cause of AIDS. The earliest known case was from a blood sample collected in 1959 from a man in Kinshasa in the Democratic Republic of Congo.
Types: There are currently two types of HIV: HIV-1 and HIV-2.
HIV-1 is predominant worldwide and mutates very easily. Different strains of HIV-1 also exist and are categorised in groups and subtypes (clades).
HIV-2 was identified in 1986 and is prevalent in West African countries. There are many similarities between HIV-1 and HIV-2 (e.g. both are transmitted in the same way, both are associated with similar opportunistic infections and AIDS), but in persons infected with HIV-2, immunodeficiency develops more slowly and the virus is less infectious.
AIDS is the final stage of HIV infection and is usually characterised by a CD4 count of less than 200.
AIDS is not a specific illness but rather a collection of illnesses that affect the body and to which the weakened immune system struggles to respond.
HIV is transmitted through body fluids such as blood, semen, vaginal fluid, breast milk and other fluids containing blood.
The virus can be transmitted through the following ways, among others:
The virus can also be transmitted via oral sex as body fluids can be transferred through cuts or sores around or in the mouth or throat. The risk of HIV-transmission through oral sex is extremely low.
No evidence has been found that the virus can be transmitted through kissing (unless intraoral bleeding occurs), saliva, tears, sweat, or via insects (such as mosquitoes), according to the US Centers for Disease Control & Prevention (CDC).
Not all people who are HIV-positive necessarily have AIDS. Technically, only those with CD4 counts under 200 have AIDS.
According to conventional science, people cannot have AIDS without being HIV-positive first.
The following statement would be insensitive and possibly incorrect: "Newly crowned Miss HIV Stigma-Free, Kgalalelo Ntsepe, has AIDS."
More sensitive: "Newly crowned Miss HIV Stigma-Free, Kgalalelo Ntsepe, is openly HIV-positive."
Of course, naming people who are HIV-positive is in itself ethically complicated. See the ethics section for a more detailed discussion of this.
After infection, the HI virus enters the blood and attacks the body's immune system, specifically the important T-helper cell which co-ordinates the immune system's response to infections. The HI virus gains entry to the T-helper cell by attaching itself to the CD4 protein on the surface of the cell. Once the HIV has gained entry, it takes over the cell and replicates, seeking new T-helper cells to infect. The infected cell dies after a couple of days.
The body's natural response to an infection is to fight infected cells and replace the cells that have been lost. This response encourages the virus to reproduce itself. This is a gradual process that eventually damages the body's immune system and leaves the body vulnerable to infections and other diseases. The time it takes to do this varies from person to person, but averages at about nine years.
The normal range for CD4+T cells in a healthy person is 800-1200 cells per cubic millilitre of blood. When an HIV infected person's CD4+ T cell count falls below 200, he or she becomes increasingly vulnerable to opportunistic infections. In a person with a healthy immune system these infections would not normally be life-threatening but to an HIV-infected person they could be fatal.
Without treatment, the viral load, which refers to the relative amount of free virus in the blood plasma, will increase to the point where the body can no longer fight it.
HIV progression can be divided into 4 stages:
| Stage | Description | Symptoms |
| 1. Primary HIV infection | During this stage most individuals will not be aware they are infected. Symptoms normally occur within three months of infection and generally subside within two weeks. | A flu-like illness, swollen lymph nodes, diarrhoea, fever and fatigue. |
| 2. Asymptomatic stage | No symptoms manifest but the virus remains active. | |
| 3. Symptomatic stage | Individual begins to feel unwell and experiences infections caused by bacteria and viruses that surround us all daily | Thrush, Herpes Zoster (shingles), Herpes Simplex, Oral Hairy Leukoplakia, Idiopathic Thrombocytopenic Purpura and Pneumococcal Pneumonia. |
| 4. Acquired Immune Deficiency Syndrome (AIDS) | Individual's CD4 count is less than 200. | Pneumocystic Pneumonia, Kaposi's Sarcoma, Tuberculosis, HIV-Related Lymphoma, (more...) |
The progression of the virus can be measured by a CD4 test that measures the amount of CD4 or T-helper cells in your blood. The strength of your immune system is a good predictor of how you will fight infections.
The Viral Load test measures the amount of HIV in the blood in every millilitre of blood. A high viral load indicates that the patient is either in the first stage of infection or nearing AIDS.
The course of an HIV infection. Graph showing HIV copies and CD4 counts over course of a typical HIV infection. As the virus replicates itself, as indicated by the red line, the number of T-helper cells in a person's blood decreases, as indicated by the blue line. Wikipedia.
HIV infection can be diagnosed through an HIV antibody test. When a person is infected with HIV, the body produces proteins to fight the virus. These are called antibodies. The body usually produces antibodies within 3-8 weeks in response to the infection. The period following infection but before antibodies can be detected by the test is known as the "window period". Because it is possible to test negative during this period, people who have been exposed to HIV are encouraged to take another test three months later to ensure that they are HIV-negative.
John Hodgkiss/Perinatal HIV Research Unit (PHRU)
Tests can be conducted using samples of blood, saliva or urine.
In South Africa the most common test used is the Rapid Test, which provides a result in 10-30 minutes. If the test is positive this is followed up by confirmatory test, which utilises the Elisa Test.
Testing for HIV should be conducted along with pre- and post-test counselling. People are counselled before an HIV test to ensure they understand the benefits of an HIV test and how they should respond to the result, particularly if they test HIV-positive. Post-test counselling is provided to lend emotional support to the individual and offer appropriate medical and social advice.
In South Africa an HIV test may be undertaken through private doctors, at public (i.e. government) clinics and hospitals, or at laboratories. In some urban areas tests can be undertaken at the AIDS Training, Information and Counselling Centre (ATICC).
At least 67% of South African public health clinics provide voluntary counselling and testing. 690 537 people used VCT services in 2003/04, according to the health ministry.
The Nelson Mandela/HIV Prevalence Incidence Behaviour and Communication Survey 2005 found that most people (78.8%) were aware of VCT services nearby. Of those who have never been tested for HIV, 12.8% were found to be HIV-positive. Only 4.6% of those tested at government facilities "were neutral or unsatisfied with the service", however the press has reported cases of poor counselling in South Africa.
Over a dozen rapid home-testing products are marketed on the Internet. The testing kits enable users to test themselves for HIV antibodies and have the results within minutes in the privacy of their homes. However, many of the kits have not been medically approved and none are sanctioned by the Food and Drug Administration (FDA) in the USA.
The only home testing kit legally approved by the Food and Drug Administration is Home Access. Users have to mail in a blood sample and phone a toll-free telephone number to retrieve their results. Post-test counselling is provided by telephone when the results are obtained (See FDA factsheet).
OraSure Technologies is seeking approval from the FDA for over-the-counter (OTC) sales of its OraQuick Advance rapid HIV-testing kits. In November 2005, the FDA concluded that the tests "would provide a public health benefit if approved for OTC use", according to its internal news agency. The FDA will meet in March 2006 to discuss the matter further.
In South Africa, home-testing kits are generally not sold in the public sector. In May 2005, a franchise of the Pick 'n Pay supermarket chain was lambasted by the South African Medical Association for selling HIV self-testing kits. The franchise subsequently stopped selling the kits.
The South African Department of Health stipulates that HIV/AIDS testing must be accompanied by pre- and post-test counselling, which is impossible to guarantee with rapid home HIV testing.
Also see:
Although there is no cure for HIV/AIDS, several treatments can be used to prolong the lives of those infected with HIV, reduce the chance of mother-to-child transmission, or prevent HIV infection after exposure to the virus (post-exposure prophylaxis).
Although antiretroviral treatment is not a cure for HIV/AIDS, it can significantly prolong and improve the lives of HIV-infected people.
There is still debate over when to start antiretroviral treatment. Because the ARV treatment has known side effects, including short and long-term toxic effects on the body, medical specialists disagree over when to start the therapy. The currently accepted guideline is to begin antiretroviral therapy when the patient's CD4 count is below 200, or he/she has displayed an AIDS-defining illness.
Antiretroviral treatment is usually a combination of drugs. The three main types of drugs available are listed below:
| Antiretroviral drug | Action | Generic examples (abbr) |
| Nucleoside Analogue Reverse Transcriptase Inhibitor (NRTI) | Prevents healthy T-cells from becoming infected with HIV by preventing the conversion of viral RNA into viral DNA. | zidovudine (AZT); lamivudine (3TC); zalcitabine (ddC); |
| Non-nucleoside Reverse Transcriptase Inhibitors (NNRTI) | Prevents healthy T-cells from becoming infected with HIV by interfering with the reverse transcriptase enzyme which the HIV uses to convert viral RNA to viral DNA. | nevirapine (NVP, delavirdine (DLV), efavirenza (EFV) |
| Protease Inhibitor | Prevents infected T-cells from producing new copies of the virus by blocking the protease enzyme which helps produce new copies of the virus. | lopinavir (LPV), ritonavir (RTV), indinavir (IDV) |
Although antiretroviral treatment is available around the world, rollout of the drugs in the public sector in South Africa has been slow. (Also see: Treatment factsheet)
A woman who is HIV-positive can pass on HIV to her baby during pregnancy, during childbirth and during breastfeeding. In the absence of preventative interventions, the probability that an HIV-positive woman's baby will become infected is approximately 25% – 35%, according to Unicef. Two treatment options, ziduvidine (AZT) and nevirapine, are available to reduce the transmission of HIV/AIDS from mother to child.
When individuals are potentially exposed to HIV through sexual assault or occupational exposure, a program of several antiviral drugs may be taken to prevent infection. Although PEP is theoretically available at all public sector hospitals and clinics, South Africa has been criticised by Human Rights Office for the slow rollout of the programme. PEP treatment needs to be commenced within 72 hours, although there is evidence to suggest that the sooner the person commences treatment the greater the benefits.
Global Summary of the AIDS epidemic (December 2005):
| Number of people living with HIV in 2005 | 40.3-million |
| Adults | 38-million |
| Women | 17.5-million |
| Children under 15 years | 2.3-million |
| People newly infected with HIV in 2005 | 4.9-million |
| Adults | 4.2-million |
| Children under 15 years | 700 000 |
| AIDS deaths in 2005 | 3.1-million |
| Adults | 2.6-million |
| Children under 15 years | 570 000 |
Source:  AIDS Epidemic Update: December 2005 |
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Based on the annual antenatal survey, the SA National Department of Health estimated that 5.6-million South Africans were HIV-positive by the end of 2003.
A study based on the results of the Actuarial Society of South Africa's ASSA2002 model, The Demographic Impact of HIV/AIDS in South Africa. National Indicators for 2004, produced the following estimates:
The ASSA2002 model projects that there are likely to be about 346,000 AIDS deaths between July 2005 and July 2006 (one year), despite interventions including treatment. The number of accumulated AIDS deaths is likely to reach 3.3-million by 2010.
