HIV/AIDS: Etiology, Symptoms, and Treatment Overview

Introduction

HIV/AIDS is one of the most prevalent and devastating diseases in the world today. It has already killed millions throughout the world, especially in developing countries such as those in Africa. The importance of HIV as a global health issue — and the broader social consequences the virus carries for many countries — makes it a critical subject of study. The statistics accumulated over recent decades are evidence of both the growth and the devastating effect of this virus. The total number of recorded deaths due to HIV/AIDS between 1981 and 2003 was a staggering 20 million. The number of children in Sub-Saharan Africa orphaned by the end of 2003 was an estimated 12 million. Later figures indicate that the situation in Africa has not improved; these numbers increased in 2004, particularly among women. "By December 2004, women accounted for 47% of all people living with HIV worldwide, and for 57% in sub-Saharan Africa" (World HIV and AIDS Statistics).

HIV/AIDS infects not only individuals but entire societies. As one account observed, AIDS "migrated to man in Africa, it mutated into a complex plague with ... social, economic and political dynamics that ... accelerate the virus' progress" (Death Stalks a Continent).

Definition of HIV and AIDS

The term HIV/AIDS refers to Acquired Immune Deficiency Syndrome, which is caused by the HIV virus. HIV stands for Human Immunodeficiency Virus. AIDS itself refers to the complex of diseases that result from the HIV attack on and intrusion into the human immune system. The term syndrome means a "group of health problems that make up a disease." An individual is HIV-positive when the body creates antibodies to fight the HIV virus. "When you get a blood test for HIV, the test looks for these antibodies. If you have them in your blood, it means that you have HIV infection. People who have the HIV antibodies are called 'HIV-Positive'" (What Is AIDS?).

There is therefore a connection — but also an important distinction — between being HIV-positive and having AIDS.

Being HIV-positive, or having HIV disease, is not the same as having AIDS. Many people are HIV-positive but do not get sick for many years. As HIV disease continues, it slowly wears down the immune system. Viruses, parasites, fungi, and bacteria that usually do not cause any problems can make a person very sick if the immune system is damaged. These are called "opportunistic infections" (ibid).

Etiology: How HIV Works

Infection from the HIV virus occurs through direct transmission from person to person in several possible ways. The most common modes of transmission are sexual contact with an infected person, contaminated needles, and transmission to a baby from an infected mother — including through breast milk. Infection through blood transfusions has also been recorded; however, in most countries blood supplies are now more strictly screened, making this mode of transmission extremely rare.

The HIV virus functions in the body by attaching to living cells. Because the virus cannot reproduce without parasitically attaching itself to a host cell, it primarily targets an immune cell known as a lymphocyte — more specifically, "a CD4 helper cell, a type of T-cell" (Pieribone, D.).

T-cells are a vital part of the immune system because they facilitate the body's ability to combat many potentially fatal infections. Without T-cells, the body cannot provide the necessary protection against opportunistic infections. The HIV life cycle effectively reduces the number of T-cells within the human body, which in turn results in greater susceptibility to infection. The precise process through which this occurs is not completely understood (ibid). In effect, HIV will "hijack the T-cell's cellular machinery" (ibid) and then reproduce thousands of copies of the virus, which invade more T-cells, further reducing the body's resistance and increasing the likelihood of opportunistic disease and full-blown AIDS. Many steps are involved before the process of viral duplication is complete. An example of part of this complex process is as follows:

Once HIV comes into contact with a T-cell, it must attach itself to the cell so that it can fuse with the cell and inject its genetic material — a blueprint for making more HIV — into it. Attachment is a specific binding between proteins on the surface of the virus and proteins that serve as receptors on the surface of the T-cell. Normally, these receptors help the cell communicate with other cells. Two receptors in particular, CD4 and a beta-chemokine receptor (either CCR5 or CXCR4), are used by HIV to latch onto the cell. On the surface of the viral envelope, two sets of proteins — also known as antireceptors — called gp120 and gp41 attach to CD4 and CCR5/CXCR4 (Pieribone, D.).

Conclusion

The continued increase in HIV infections and AIDS-related deaths is a cause for alarm, particularly in developing areas such as Sub-Saharan Africa. The figures and statistics speak for themselves, and the growing number of those infected is having a dramatic effect on many parts of the world.

During 2004, around five million adults and children became infected with HIV, the virus that causes AIDS. By the end of that year, an estimated 39.4 million people worldwide were living with HIV/AIDS. The year also saw more than three million deaths from AIDS, despite the availability of antiretroviral therapy, which had reduced the number of deaths in high-income countries (World HIV and AIDS Statistics).

The problem of HIV infection is further compounded by the growing need for affordable medicines in developing countries. Expanding access to antiretroviral treatment remains one of the most urgent challenges in the global response to the epidemic.

Bibliography

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Death Stalks a Continent. Time Magazine, February 12, 2001.

World HIV and AIDS Statistics. Avert. 2004. http://www.avert.org/worldstats.htm

Pieribone, D. The HIV Life Cycle. ACRIA. 2003.

What Is AIDS? New Mexico AIDS InfoNet. 2003. http://www.thebody.com/nmai/whatisaids.html

What Is AIDS? AIDS.org. 2003.