HIV and AIDS

A/Prof A. Lloyd (Inflammation Research Unit, School of Pathology, UNSW)

Background:

The worldwide epidemic of infection with the Human Immunodeficiency Virus (HIV) has challenged the medical and scientific communities to rapidly develop an understanding of the nature of the virus and its transmission as well as to develop effective treatment and prevention strategies. Similarly, the epidemic has personally touched the great majority of individuals across the globe with relatives, friends, neighbours or acquaintances affected and often dying as a result of the acquired immune deficiency syndrome (AIDS) which is caused by HIV infection.

Basic Statistics:

According to the Joint United Nations Programme on HIV/AIDS , as of the end of 1999, the following trends of the worldwide epidemic (or pandemic) of HIV are evident:

• Today, 33.6 million people are estimated to be living with HIV/AIDS. Of these, 32.4 million are adults. 14.8 million are women, and 1.2 million are children under 15.

• An estimated 16.3 million people have died from AIDS since the epidemic began. 12.7 million were adults, including 6.2 million women. 3.6 million were children under 15.

• During 1999, HIV-associated illnesses caused the deaths of an estimated 2.6 million people, including 1.1 million women and 470,000 children under 15.

• Women are becoming increasingly affected by HIV. Approximately 46%, or 14.8 million, of the 32.4 million adults living with HIV or AIDS worldwide are women.

• The overwhelming majority of people with HIV - some 95% of the global total - now live in the developing world.

• By the end of 1999, the epidemic had left behind a cumulative total of 11.2 million AIDS orphans, defined as those having lost their mother before reaching the age of 15. Many of these maternal orphans have also lost their father.

The miracle

Within a decade of the isolation of HIV, an immense amount of knowledge has been gained of the molecular and biochemical structure of the virus, as well as details of the way in which it infects humans and destroys the body’s defense system against infection and cancer - the immune system. One of the "miracles" of this decade of scientific endeavour has been the application of highly sophisticated techniques to identify genes of HIV which provide the code for proteins which are critical to viral replication. One such protein is the HIV protease, a viral enzyme that is essential for the assembly of HIV proteins into new particles thus allowing the continued cycle of viral replication and re-infection of host immune cells. Furthermore, this protein has been synthesised in the laboratory and crystallised in order to define the three dimensional structure of the viral enzyme. The recognition of the pocket-like structure which is essential for HIV protease to function, then led to the design of tailor-made drugs which could bind to, and inactivate, the viral enzyme. Thus, a family of new anti-HIV drugs have been developed (protease inhibitors) which now provide the cornerstone of modern treatment programmes for patients with HIV/AIDS.

The misadventure

Despite the dramatic advances in understanding of the mechanisms underlying the viral infection, in the great majority of countries, the HIV epidemic continues to grow. The circumstances in which HIV is transmitted, that is by blood-to-blood or sexual contact, are now well understood. The "misadventure" of HIV/AIDS is the continuing lack of control of the epidemic in countries of the Third world. Foremost in this regard is the rapidly worsening increasing number of cases and deaths in countries of the Asian sub-continent, notably Thailand and India, and the countries of the Pacific rim, notably Papua New Guinea. Given that the development of an effective vaccine for HIV appears to be many years away, the key to control of the epidemic in these countries is effective education and public health programmes.

The potential for loss of control of the epidemic in Western countries also remains high, notably in settings where key risk factors for transmission remain prevalent. This possibility is clearly evident in prisons where injecting drug use continues to be very common and other blood-to-blood contacts (e.g via fights and tattooing) are also frequent.Thus, an additional public health challenge for the developed world is to implement effective prevention programmes in settings such as prisons.

2:00 - 3:00 Lecture: Overview of the principles of our understanding of HIV/AIDS and a review of the miracle and misadventure outlined above.

Web Presentation of Lecture Slides or
Download PDF Version

3:00 - 4:00 Internet research

The class will be divided into two groups. Each group will collect information in order to complete one of the tasks below:

1. To develop the outline for a HIV/AIDS prevention programme for inmates of Australian prisons. The aims of the programme will be to: (i) identify the level of 'at-risk' behaviour amongst inmates; (ii) develop a system to monitor the number of inmates infected with HIV before, and during, imprisonment; and (iii) develop an appropriate prevention strategy to control spread of HIV in prisons utilising all suitable means.
2. To develop an outline for a public health intervention strategy for control of HIV/AIDS in our nearest Pacific neighbour, Papua New Guinea. The aims of the strategy will include: (i) identification of the number of people already infected and to monitor the rate of new infections (surveillance); and (ii) to educate the population about HIV/AIDS and its transmission.

4:00 - 5:00 Group Discussion and Feedback

Assignment Topics:

Students who chose to complete the assignment for this General Studies subject on the topic of HIV/AIDS should develop a poster or Website on the same topic as either (1) or (2) above.

Web-based Resources:

1. HIV in Prisons

WHO Guidelines on HIV Infection and AIDS in Prisons

HIV/AIDS Preventive Activities in Prisons

University of California HIV/AIDS Program - Prison Knowledge Base

Johns Hopkins AIDS Service

2. HIV Education in PNG

Papua New Guinea Epidemiological Fact Sheet on HIV/AIDS

University of California HIV/AIDS Program - Asia Knowledge Base

Johns Hopkins AIDS Service - Epidemiology

General Resources

United Nations AIDS program - Includes estimated numbers of cases and HIV infections country by country.

University of California HIV/AIDS program - Includes "The AIDS Knowledge Base" a 1600 page textbook with updates on various aspects of AIDS.

Miracles and Misadventures Home Page

Page maintained by: Dr Gary Velan
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Last modified: 25/07/2001