AIDS

The Red Ribbon is the global symbol for solidarity with HIV positive and people living with AIDS. The Red Ribbon made its public debut when host Jeremy Irons wore it during the 1991 Tony Awards.[1]

AIDS is an acronym for Acquired Immunodeficiency Syndrome or Acquired Immune Deficiency Syndrome. It is a collection of symptoms and infections resulting from the depletion of the immune system caused by infection with the human immunodeficiency virus or HIV.

The virus that causes AIDS is transmitted through sexual relationships, by sharing contaminated needles, through blood transfusions, mishandling contaminated blood as well as during pregnancy, childbirth and breastfeeding. But, primarily HIV is transmitted through sexual relationships. Therefore, HIV/AIDS is both a medical and a moral concern. Effective prevention strategies must take into account both dimensions of the disease.

Global pandemic

AIDS is thought to have originated in sub-Saharan Africa during the twentieth century, it is now a global epidemic. The World Health Organization estimated that, worldwide, between 2.8 and 3.5 million people with AIDS died in 2004. [2]

UNAIDS and the World Health Organization WHO estimated that between 36 and 44 million people around the world were living with HIV in December 2004 [3]. It was estimated that during 2004, between 4.3 and 6.4 million people were newly infected with HIV and between 2.8 and 3.5 million people with AIDS died. Sub-Saharan Africa remains by far the worst-affected region, with 23.4 million to 28.4 million people living with HIV at the end of 2004. Just under two thirds (64%) of all people living with HIV are in sub-Saharan Africa, as are more than three quarters (76%) of all women living with HIV. [4] South & South East Asia are second most affected with 15%. AIDS accounts for the deaths of 500,000 children.

World region	Estimated adult prevalence of HIV infection (ages 15–49)	Estimated adult and child deaths during 2004
Sub-Saharan Africa	6.9% to 8.3%	2.1 to 2.6 million
Caribbean	1.5% to 4.1%	24,000 to 61,000
Asia	0.3% to 0.6%	350,000 to 810,000
Eastern Europe and Central Asia	0.5% to 1.2%	39,000 to 87,000
Latin America	0.5% to 0.8%	73,000 to 120,000
Oceania	0.1% to 0.3%	fewer than 1,700
Middle East and North Africa	0.1% to 0.7%	12,000 to 72,000
North America, Western and Central Europe	0.3% to 0.6%	15,000 to 32,000

Source: UNAIDS and the WHO 2004 estimates. The ranges define the boundaries within which the actual numbers lie, based on the best available information. [5]

Prevention

File:R402a1t1.gif

CDC 2005

As with all diseases, prevention is better than cure. This is all the more true for HIV/AIDS because although treatments for both AIDS and HIV exist, there is currently no known cure or vaccine.

Preventing HIV/AIDS requires a two pronged approach: strengthening moral values for the general population and targeting high risk groups (sex traffickers, drug uses and those likely to engage in non-marital sex) with barrier devices such as condoms.

According to a recent report from the U.S. Agency for International Development USAID, there is only one country in the world that has substantially turned back the HIV/AIDS pandemic.

Uganda is the standout among countries that have effectively responded to HIV/AIDS under the guidance of national leadership in both the political and religious realms. Uganda has experienced the most significant decline in HIV prevalence of any country in the world. (Green, 2003)

Uganda’s model, developed indigenously, is called the ABC model. Here “A” stands for Abstinence, “B” for Be faithful, and “C” for Condoms (used correctly and consistently). Importantly, equal emphasis was not given to each component. Ugandans put the primary emphasis on “A” and “B.” All the while, condom distributed continued through the Ministry of Health, under a “Policy of Silent Promotion” (Dyer, 2003).

Uganda’s success has been well documented and heavily scrutinized. In a generalized heterosexual population HIV prevalence declined nearly 70 percent since the early 1990s. Importantly, it was accompanied with a 60 percent reduction in casual sex. The decline of HIV prevalence in 15- to 19-year-olds was 75 percent and was seen as a key to Uganda’s success (Green, et al., 2005). The annual cost was $1 per person aged 15 and above. If this ABC program been implemented throughout sub-Saharan Africa by 1996, it is estimated that there would be 6 million fewer persons infected with HIV and 4 million fewer children would have been orphaned (Green, et al., 2005).

The Vatican and other religious groups oppose the use of condoms. Having a dual approach to HIV/AIDS prevention allows both the faith-based organizations and the medical professionals to work towards a common goal. Religious communities have vast networks that reach into the most rural areas, they are powerful agents for behavioral and social change, they can mobilize volunteers, and the have experience in health care and education.

In Uganda, was important that the condom message be specifically targeted and not mass marketed. This did two things: 1) it helped the condom message be “very effective” (Green, et al., 2005) in these high-risk groups by defining a smaller target that could be more easily educated, trained and more effectively monitored, and 2) it did not undermine the message that human sexuality should be exclusively an act of marriage, a belief and practice that protects the general population.

Safer sex

The male latex condom is the single most efficient available technology to reduce the sexual transmission of HIV and other sexually transmitted infections. With consistent and correct use of condoms, there is a very low risk of HIV infection. Studies on couples where one partner is infected show that with consistent condom use, HIV infection rates for the uninfected partner are below 1% per year.[6]

The US government and US health organizations both endorse the ABC Approach to lower the risk of acquiring AIDS during sex:

• Abstinence or delay of sexual activity, especially for youth,
• Being faithful, especially for those in committed relationships,
• Condom use, for those who engage in risky behavior.

This approach has been very successful in Uganda, where HIV prevalence has decreased from 15% to 5%. However, the ABC approach is far from all that Uganda has done, as "Uganda has pioneered approaches towards reducing stigma, bringing discussion of sexual behavior out into the open, involving HIV-infected people in public education, persuading individuals and couples to be tested and counseled, improving the status of women, involving religious organizations, enlisting traditional healers, and much more." (Edward Green, Harvard medical anthropologist). Also, it must be noted that there is no conclusive proof that abstinence-only programs have been successful in any country in the world in reducing HIV transmission. This is why condom use is heavily co-promoted. There is also considerable overlap with the CNN Approach. This is:

• Condom use, for those who engage in risky behavior.
• Needles, use clean ones
• Negotiating skills; negotiating safer sex with a partner and empowering women to make smart choices

The ABC approach has been criticized, because a faithful husband or wife of an unfaithful partner is at risk of AIDS [7]. Many think that the combination of the CNN approach with the ABC approach will be the optimum prevention platform.

HIV blood screening

In those countries where improved donor selection and antibody tests have been introduced, the risk of transmitting HIV infection to blood transfusion recipients has been effectively eliminated. According to the WHO, the overwhelming majority of the world's population does not have access to safe blood and "between 5% and 10% of HIV infections worldwide are transmitted through the transfusion of infected blood and blood products." [8]

Medical procedures

Medical workers who follow universal precautions or body substance isolation such as wearing latex gloves when giving injections and washing the hands frequently can help prevent infection of HIV. The risk of being infected with HIV from a single prick with a needle that has been used on an HIV infected person though is thought to be about 1 in 150 (see table above). Post-exposure prophylaxis with anti-HIV drugs can further reduce that small risk. [9]

Universal precautions are frequently not followed in both sub-Saharan Africa and much of Asia because of both a shortage of supplies and inadequate training. The WHO estimates that approximately 2.5% of all HIV infections in sub-Saharan Africa are transmitted through unsafe healthcare injections. [10]. Because of this, the United Nations General Assembly, supported by universal medical opinion on the matter, has urged the nations of the world to implement universal precautions to prevent HIV transmission in health care settings [11].

Universal precaution gets its name from the idea that precautions are to be used every single time, and not merely when the healthcare worker thinks that a patient might be high-risk for a transmissable disease.

Intravenous drug use

HIV can be transmitted by the sharing of needles by users of intravenous drugs. Cumulative data from 1981 to 2001 has shown that 31% of people with AIDS in the United States are injection drug users [12]. All AIDS-prevention organisations advise drug-users not to share needles and to use a new or properly sterilized needle for each injection. Information on cleaning needles using bleach is available from health care and addiction professionals and from needle exchanges. In the United States and other western countries, clean needles are available free in some cities, at needle exchanges or safe injection sites.

Mother to child transmission

There is a 15–30% risk of transmission of HIV from mother to child during pregnancy, labour and delivery. A number of factors influence the risk of infection, particularly the viral load of the mother at birth (the higher the load, the higher the risk). Breastfeeding increases the risk of transmission by 10–15%. This risk depends on clinical factors and may vary according to the pattern and duration of breastfeeding.

Studies have shown that antiretroviral drugs, cesarean delivery and formula feeding reduce the chance of transmission of HIV from mother to child. (Sperlin et al., 1996)

When replacement feeding is acceptable, feasible, affordable, sustainable and safe, HIV-infected mothers are recommended to avoid breast feeding their infant. Otherwise, exclusive breastfeeding is recommended during the first months of life and should be discontinued as soon as possible. [13]

Transmission and infection

Scanning electron micrograph of HIV-1 budding from cultured lymphocyte.

Patterns of HIV transmission vary in different parts of the world. In sub-Saharan Africa, which accounts for an estimated 60% of new HIV infections worldwide, controversy rages over the respective contribution of medical procedures, heterosexual sex and the bush meat trade. In the United States, sex between men (35%) and needle sharing by intravenous drug users (15%) remain prominent sources of new HIV infections. [14] In January 2005, Anthony S. Fauci, M.D., director of NIAID said, "Individual risk of acquiring HIV and experiencing rapid disease progression is not uniform within populations". NIH press release Some epidemiological models suggest that over half of HIV transmission occurs in the weeks following primary HIV infection before antibodies to the virus are produced. [15] [16] Investigators have shown that viral loads are highest in semen and blood in the weeks before antibodies develop and estimated that the likelihood of sexual transmission from a given man to a given woman would be increased about 20-fold during primary HIV infection as compared with the same couple having the same sex act 4 months later. [17] Most people who are infected typically suffer from days to weeks of fever with or without muscle and joint aches, fatigue, headache, sore throat, swollen glands and sometimes rash. This "acute retroviral syndrome" is rarely diagnosed because it is difficult to distinguish from other very common ailments.

The Centers for Disease Control (CDC) in the United States reported a cluster of HIV infections in 13 of 42 young women who reported sexual contact with the same HIV infected man in a rural county in upstate New York between February and September 1996 [18]

The risk of oral sex has always been controversial. [19] Most of the early AIDS cases could be attributed to anal sex or vaginal sex. As the use of condoms became more widespread, there were reports of AIDS acquired by oral sex. [20] Unprotected oral sex is widely understood to be less risky than unprotected vaginal sex, which in turn is less risky than unprotected anal sex.

Heterosexual transmission of HIV-1 depends on the infectiousness of the index case and the susceptibility of the uninfected partner. Infectivity seems to vary during the course of illness and is not constant between individuals. Each 10 fold increment of seminal HIV RNA is associated with an 81% increased rate of HIV transmission. [21] During 2003 in the United States, 19% of new infections were attributed to heterosexual transmission [22]

The argument about the exact incidence of HIV transmission per act of intercourse is academic. Infectivity depends critically on social, cultural, and political factors as well as the biological activity of the agent. Whether the epidemic grows or slows depends on infectivity plus two other variables: the duration of infectiousness and the average rate at which susceptible people change sexual partners. [23]

Genetic susceptibility

File:300px-800px-HIV Viron.png

Diagram of an HIV viron

CDC has released findings that genes influence susceptibility to HIV infection and progression to AIDS. HIV enters cells through an interaction with both CD4 and a chemokine receptor of the 7 Tm family. They first reviewed the role of genes in encoding chemokine receptors (CCR5 and CCR2) and chemokines (SDF-1). While CCR5 has multiple variants in its coding region, the deletion of a 32-bp segment results in a nonfunctional receptor, thus preventing HIV entry; two copies of this gene provide strong protection against HIV infection, although the protection is not absolute. This gene is found in up to 20% of Europeans but is rare in Africans and Asians; researchers and scientists believe that HIV had a similar viral shell as the bacteria which caused the black plague (1347-1350), leading to the decimation of one-third of the European population, possibly explaining why the CCR5-32 receptor gene is more prevalent in Europeans than Africans and Asians. Multiple studies of HIV-infected persons have shown that presence of one copy of this gene delays progression to the condition of AIDS by about 2 years. And it is possible that a person with the CCR5-32 receptor gene will not develop AIDS, although they will still carry HIV.

Oral sex

While it is agreed that oral sex is a very much lower risk activity than vaginal and anal sex, it has been established that HIV can be transmitted through both insertive and receptive oral sex (Rothenberg et al., 1998). An insidious danger of this myth is that it results in increased practice of unprotected oral sex. Even if the risk of infection is very small from a single encounter, it increases with frequency of activity. The perpetuation of the "oral sex is safe" myth probably is driven by the fact that people typically find oral sex far less pleasurable with a condom or dental dam, and consequently cognitive bias inclines people to believe it is safe.

Diagnosis

The majority of people infected with HIV, if not treated, develop signs of AIDS within 8-10 years. However, 1-2% of HIV-infected individuals retain functional immune systems, despite being infected with HIV for a number of years. These individuals are known as HIV longterm non-progressors.

The Centers for Disease Control has, since 1993, defined an AIDS diagnosis in adults and adolescents in the USA as when a person presents with HIV infection and either a CD4+ T cell count below 200/µL or one of 26 of AIDS defining clinical conditions. This is different for children.

In developing countries, AIDS in adults and adolescents is identified on the basis of certain infections, grouped by the World Health Organization (WHO):

• Stage I HIV disease is asymptomatic and not categorized as AIDS
• Stage II (includes minor mucocutaneous manifestations and recurrent upper respiratory tract infections)
• Stage III (includes unexplained chronic diarrhoea for longer than a month, severe bacterial infections and pulmonary tuberculosis) or
• Stage IV (includes Toxoplasmosis of the brain, Candidiasis of the oesophagus, trachea, bronchi or lungs and Kaposi's Sarcoma) HIV disease are used as indicators of AIDS.

Treatment

There is currently no cure or vaccine for HIV or AIDS. Current optimal treatment options consist of combinations ("cocktails") consisting of at least three drugs belonging to at least two types, or "classes," of anti-retroviral agents. Typical regimens consist of two nucleoside analogue reverse transcriptase inhibitors (NRTIs) plus either a protease inhibitor or a non nucleoside reverse transcriptase inhibitor (NNRTI). This treatment is frequently referred to as HAART (highly-active anti-retroviral therapy). [24] Anti-retroviral treatments, along with medications intended to prevent AIDS-related opportunistic infections, have played a part in delaying complications associated with AIDS, reducing the symptoms of HIV infection, and extending patients' life spans. Over the past decade the success of these treatments in prolonging and improving the quality of life for people with AIDS has improved dramatically. [25], [26].

However, treatment guidelines are changing constantly. The current guidelines for antiretroviral therapy from the World Health Organization reflect the 2003 changes to the guidelines and recommend that in resource-limited settings (i.e., developing nations), HIV-infected adults and adolescents should start ARV therapy when HIV-infection has been confirmed and one of the following conditions is present:

• Clinically advanced HIV disease:
• WHO Stage IV HIV disease, irrespective of the CD4 cell count;
• WHO Stage III disease with consideration of using CD4 cell counts <350/µl to assist decision-making.
• WHO Stage I or II HIV disease with CD4 cell counts <200/µl

The US Department of Health and Human Services, the federal agency responsible for overseeing HIV/AIDS healthcare policies in the United States, have recently stated on April 7, 2005 that:

• All patients with history of an AIDS-defining illness or severe symptoms of HIV infection regardless of CD4+ T cell count receive ART.
• Antiretroviral therapy is also recommended for asymptomatic patients with <200 CD4+ T cells/µl
• Asymptomatic patients with CD4+ T cell counts of 201–350 cells/µl should be offered treatment.
• For asymptomatic patients with CD4+ T cell of >350 cells/µl and plasma HIV RNA >100,000 copies/ml most experienced clinicians defer therapy but some clinicians may consider initiating treatment.
• Therapy should be deferred for patients with CD4+ T cell counts of >350 cells/µl and plasma HIV RNA <100,000 copies/mL.

The preferred initial regimens are either:

• efavirenz + lamivudine or emtricitabine + zidovudine or tenofovir; or
• lopinavir boosted with ritonavir + zidovudine + lamivudine or emtricitabine.

The DHHS also recommends that doctors should assess the viral load, rapidity in CD4 decline, and patient readiness while deciding when to begin treatment. [27]

There are several concerns about antiretroviral regimens. The drugs can have serious side effects (Saitoh et al., 2005). Regimens can be complicated, requiring patients to take several pills at various times during the day. If patients miss doses, drug resistance can develop. [28] Also, anti-retroviral drugs are costly, and the majority of the world's infected individuals do not have access to medications and treatments for HIV and AIDS.

Research to improve current treatments includes decreasing side effects of current drugs, simplifying drug regimens to improve adherence, and determining the best sequence of regimens to manage drug resistance.

Alternative medicine

Ever since AIDS entered the public consciousness, various forms of alternative medicine have been used to treat its symptoms. In the first decade of the epidemic when no useful conventional treatment was available, a large number of people with AIDS experimented with alternative therapies (massage, herbal and flower remedies and acupuncture). Interest in these therapies has declined over the past decade as conventional treatments have improved. People with AIDS, like people with other illnesses such as cancer, also sometimes use marijuana to treat pain, combat nausea and stimulate appetite.

Research

Origin

The official date for the beginning of the AIDS epidemic is marked as June 18, 1981, when the US Center for Disease Control and Prevention reported a cluster of Pneumocystis carinii pneumonia (now classified as Pneumocystis jiroveci pneumonia) in five gay men in Los Angeles in the early 1980s. [29] Originally dubbed GRID, or Gay-Related Immune Deficiency, health authorities soon realized that nearly half of the people identified with the syndrome were not gay. Reporter Randy Shilts discovered the name of an extremely sexually active man, Gaëtan Dugas, who epidemiologists at the time suspected to be the first carrier of what was first called "gay-plague", but later research failed to track the epidemic to any individual carrier. [30] In 1982, the CDC introduced the term AIDS to describe the newly recognized syndrome.

Three of the earliest known instances of HIV infection are as follows:

1. A plasma sample taken in 1959 from an adult male living in what is now the Democratic Republic of Congo.
2. HIV found in tissue samples from an American teenager who died in St. Louis in 1969.
3. HIV found in tissue samples from a Norwegian sailor who died around 1976.

Two species of HIV infect humans: HIV-1 and HIV-2. HIV-1 is more virulent and more easily transmitted. HIV-1 is the source of the majority of HIV infections throughout the world, while HIV-2 is less easily transmitted and is largely confined to West Africa. [31] Both HIV-1 and HIV-2 are of primate origin. The origin of HIV-1 is the Central Common Chimpanzee (Pan troglodytes troglodytes). The origin of HIV-2 has been established to be the Sooty Mangabey, an Old World monkey of Guinea Bissau, Gabon, and Cameroon.

Circumcision

Current research is clarifying the relationship between male circumcision and HIV in differing social and cultural contexts. UNAIDS believes that it is premature to recommend male circumcsion services as part of HIV prevention programmes. [32]

South African medical experts are concerned that the repeated use of unsterilised blades in the ritual circumcision of adolescent boys may be spreading HIV. [33]

Vaccine research

As there is no known cure for AIDS, the search for a vaccine against the etiological agent, HIV, has become part of the struggle against the disease. Only a vaccine will be able to halt the pandemic. This would possibly cost less, thus being affordable for developing countries, and would not require daily treatments. However, after over 20 years of research, HIV remains a difficult target for a vaccine and there is still no vaccine available; a June 2005 study estimates that $682 million is spent on AIDS vaccine research annually [34].

Alternative theories

A minority of scientists and activists question the connection between HIV and AIDS, or the existence of HIV, or the validity of current testing methods. These claims are met with resistance by, and often evoke frustration and hostility from, most of the scientific community, who accuse the dissidents of ignoring evidence in favor of HIV's role in AIDS, and irresponsibly posing a dangerous threat to public health by their continued activities. Dissidents assert that the current mainstream approach to AIDS, based on HIV causation, has resulted in inaccurate diagnoses, psychological terror, toxic treatments, and a squandering of public funds. The debate and controversy regarding this issue from the early 1980s to the present has provoked heated emotions and passions from both sides.

Template:AIDS

References

ISBN links support NWE through referral fees

Because of their length, the list of references used in developing this article are at AIDS/references

External links

• AIDS.ORG AIDS.ORG: Educating - Raising HIV Awareness - Building Community
• AIDSinfo 2002 The Glossary of HIV/AIDS-Related Terms 4th Edition
• AIDSmeds.com 2005 AIDSmeds.com: Comprehensive lessons on HIV/AIDS and their treatments
• Center for Disease Control (2005). Divisions of HIV/AIDS Prevention
• Health Action AIDS 2003 HIV Transmission in the Medical Setting
• NIAID/NIH 2003 Basic Information About AIDS and HIV
• NIAID/NIH 2003 Evidence That HIV causes AIDS
• NIAID/NIH 2004 How HIV Causes AIDS
• The Body 2005 The Body: The Complete HIV/AIDS Resource
• UNAIDS 2005 The Joint United Nations Programme on HIV/AIDS
• Journal Watch 2005 AIDS Clinical Care
• UNAIDS Scenarios to 2025 Document regarding three scenarios for HIV/AIDS in Africa for the year 2025 (Large PDF file)

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References:

• Dyer, Emilie. (2003). And Banana Trees Provided the Shade. Kampala, Uganda: Ugandan AIDS Commission.
• Green, Edward C. (2003). Faith-Based Organizations: Contributions to HIV Prevention. Washington, DC: U.S. Agency for International Development, The Synergy Project.
• Green, Edward C., Rand L. Stoneburner, Daniel Low-Beer, Norman Hearst and Sanny Chen. (2005). Evidence That Demands Action: Comparing Risk Avoidance and Risk Reduction Strategies for HIV Prevention. Austin, TX: The Medical Institute.