An obscure article in The New York Times in 1981 reported the outbreak of a rare form of cancer (Kaposi's sarcoma) among 41 gay men in New York and California. This "cancer" was identified later on to be a complication observed at advanced stages, due to "human immunodeficiency virus (HIV)" infection. HIV targets the immune system and other parts of the body. In more advanced stages, among those infected with HIV, the immune system is so compromised, thus, the term "acquired immunodeficiency syndrome (AIDS)", making the patients vulnerable to a range of other AIDS-related illnesses and opportunistic infections, e.g., cryptococcal meningitis, Pneumocystis pneumonia, Kaposi's sarcoma, tuberculosis (TB), etc.

    Twenty years since the discovery of HIV, about 22 million people worldwide have died of AIDS and an estimated 36 million people are living with HIV or AIDS1. These numbers are more than 50% higher than previous estimates in 1991 and even higher estimates of 50 million have been reported as of 1999. In year 2000 alone, about 5 million people have been infected with HIV and about 2 million have died of AIDS.

    More than 70% of people with HIV/AIDS now live in Africa (more specifically Sub-Saharan Africa), where the majority of these cases were contracted through heterosexual transmission. In some of the countries in Sub-Saharan Africa, more than 10% of the total population are infected and still much higher among those in the 15-49 age range.

    While the complications of HIV infection was first diagnosed among gay men (and still the most predominant situation in many Western countries), recent trend indicated increased incidence of transmission among heterosexuals in other parts of the world. In fact, in Sub-Saharan Africa more women (55%) than men are infected with HIV1. Because of the prevalence of heterosexual transmission, pregnant women have transmitted the virus to their newborn during the delivery or breastfeeding.

    In the United States (US), while the initial victims of the disease were homosexuals, new cases of HIV infection and AIDS disproportionately affect the poor and certain minority groups, e.g., African-Americans and Hispanics. Thus, while AIDS is no longer among the top 15 major causes of death in the US, it has become the major leading cause of death among African-Americans aged 25-45.

    The significant drop in fatalities, among those with AIDS in Western countries, arose from significant progress in drug development to avert the progression of the disease and controlling other opportunistic infections. However, these drugs are prohibitively costly so that they are essentially out of reach to people living with HIV/AIDS in many of the less developed countries. Moreover, the HIV strains prevalent in Western countries -- where most of the antiviral drugs were developed -- are quite different from the HIV strains found in other parts of the world. It is possible that this HIV strain variation may reduce the efficacy of the drugs when used against the HIV strains that are more prevalent in other countries.

    Aside from the variety of HIV strains found in different part of the world, a more serious concern is the ability of the different viruses to mutate quite rapidly. This results in rapid development of viral resistance to current drugs against AIDS.

    The development of vaccines against HIV would be a more economically feasible strategy of combating the disease, especially in less developed countries. So far, the development of such an "AIDS vaccine" has eluded the scientific community. Moreover, even with successful development of AIDS vaccines, the efficacy of these vaccines against HIV can be thwarted by the rapid mutation of the various HIV strains.

    With increasing globalization, other HIV strains may find their way to other parts of the world via defined modes of transmission. The different HIV strains have cell targets that may be have a bearing on their modes of transmission. If the latter hypothesis is correct, specific modes of transmission of HIV may reach a critical level also in Western countries, if certain HIV strains become more globally ubiquitous.

    Considering all the above issues, it is imperative therefore that the AIDS epidemic be fought on a global scale. The UN Secretary-General Kofi Annan launched a UN initiative to raise $7-$10 billion annually to prevent the further spread of the AIDS epidemic and treat those who are already sick. The actual annual cost of combating the disease worldwide may be several fold higher than the targeted UNAIDS fund, once the total cost of patient care, education, AIDS drug, health infrastructure, etc. have been considered. So far, slightly more than $1 billion have been pledged to this initiative -- barely more than 10% of the targeted annual budget -- a far cry from the ambitious goals of the fund initiative.

    Clearly, more bold, concerted and innovative initiatives are needed to combat the AIDS epidemic.

    The AIDS Primer attempts to consolidate information about HIV and AIDS from a variety of sources. Instead of being comprehensive, the AIDS Primer focused mainly on sites that were developed by major research, educational, government and international institutions directly involved in the fight against AIDS. This will ensure that linked sites are stable and the information provided to the reader are as accurate and up-to-date as possible.

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