APPENDIX 1: TREATISE ON HIV/AIDS AND DEVELOPMENT
1. Introduction to HIV/AIDS
Doubts remain about when and how the AIDS pandemic began (Van Rensburg, 2000). Some researchers claim that HIV/AIDS evolved from simian immunodeficiency virus (SIV), others claim that HIV/AIDS may be man-made, linked to polio vaccine development. In reality, the answers to these questions, if they are ever forthcoming, will have little relevance to the control or management of the disease.
The virus affects mainly two systemsof the body,the immune system and the central nervous system, and disease manifestations result from damage to these two systems. Whilst the precise mechanisms leading to the destruction of the immune system have not yet been fully delineated, abundant epidemiologic, virologic and immunologic data support the conclusion that infection with HIV is the underlying cause of AIDS (NIH, 1995). HIV is found in body fluids such as blood, semen, vaginal fluids and breast-milk and the main transmission routes are:
• Unsafe sexual contact between a man and a women or between two men;
• Contaminated blood transfusions or bodily contact involving open bleeding wounds duringaccidents;
• Intravenous drug use with infected needles;and
• From an infected mother to her baby (Schoub, 1999).
Data on the relative risk of HIV-infection for the main transmission mechanisms is somewhat misleading (Table 1), as the probability of infection can increase dramatically depending on the volume and viral load of the HIV-infected fluid, the state of the exposed individual's immune system, the length of exposure and, in particular, the integrity of the skin or mucous membranes. For example, STD-induced skinlesions are one of the most crucialrisk generators.
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Table 1 Risk of HIV infection for the main transmission mechanisms (World Bank, 1999).
--- ,
Transmission Mechanism Probability of Infection
i
Per 1000 Exposures
I
Unsafe sex
-1
I•
Male passingHIV to female 1-2•
Female passing HIVto male 0.33- 1•
Male passingto male 5 - 30I
Transmission from mother to child 140 - 480
Intravenous drug use with contaminated needles and occupational needle-stick 3
~
injuries
Use of infected blood or blood products 900 -1000
Bodily contact with between infected blood and
•
Open bleeding wounds 3I
•
Mucous membranes 1•
Skin<1
- - - . J
Sexual contact is likely to remain the main mode of transmission in southern Africa in general, and within the mining sector in particular, but the risk of occupational exposure will rise as prevalence within the workforce increases.
Some, if not most of the confusion surrounding HIV/AIDS is due to the diverse biomedical conditions that can cause morbidity and mortality in infected individuals. Social, economic and environmental factors also play fundamental roles in the prevalence and incidence of these conditions and will influence the course of morbidity and the specific condition that eventually leads to death. The same social, economic, environmental and biomedical factors also impact on the epidemiology of HIV. However, they do not alter the fundamental connection between HIV and AIDS or the certainty that AIDS results in premature death. Some groups disagree with this conclusion, most famously South Africa's president Thabo Mbeki, but it remains the established view of the international scientific community that underpins global intervention strategies. The only conclusion worth drawing from the complex interaction of factors is that HIV/AIDS can be addressed effectively only by multidisciplinary multi-stakeholder approaches.
2. The Course of HIV-Infection
Like any other virus, HIV enters the body and begins to replicate. Many people show no signs of illness directly after infection,but some exhibit flu-like symptoms a month or two after exposure to the virus,e.g.fever, headache,malaise and enlarged lymp h nodes (NIAD, 1999). These symptoms usually disappear after a week or more.
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20
Figure 1 Cumulative probability of survival in Africa following initial HIV infection in baseline year 0 (Whiteside, 1998).
A person infected with HIV may experience a 'silent' incubation period during which there is little disease manifestation. The length of this period is very variable and depends on a number of factors including the age and health status of the individual.
Without any form of management it can take 2-10 years after infection before AIDS develops. During this time the individual can continue to participate normally in society and may appear healthy, but will be infectious and able to transmit HIV to other people.
The median period of time between infection with HIV and death is approximately 14- 20 years in the developed world. In Africa, it is only 6-8 years and around 64% of deaths occur within 5 years or less (Figure 1). The difference is due to a combination of a more aggressive strain of HIV and greater numbers of opportunistic infections and other immune system depressing factors.Untreated, death occurs 12-24 months after the onset of AIDS. Occasionally, HIV-positive persons develop AIDS and die within months and there a very small number of individuals who have yet to develop AIDS 12 or more years after becomingHIV-positive.
15 1
Considerable challenges face stakeholders wishing to undertake long-term HIV/AIDS planning. Determining who is HIV infected, establishing what stage of the disease they are in and predicting when mortality will occur, are all difficult. The lag time between HIV infection and AIDS mortality has led to many stakeholders adopting a wait-and-see approach, because the impacts of HIV/AIDS on morbidity and mortality are yet to manifest themselves, despite high HIV prevalence. Unfortunately, the best management interventions must be instituted well before this stage is reached. With the seemingly dormant state of the disease, many companies underestimate the future impacts of the disease and may be unprepared to deal with the repercussions.