   #copyright

AIDS

2007 Schools Wikipedia Selection. Related subjects: Health and medicine

   SOS Children supports more than 50,000 Aids Orphans in the community.
   For more information see SOS Children: Aids in Africa

   CAPTION: Acquired Immunodeficiency Syndrome (AIDS)
   Classifications and external resources

   The Red ribbon is a symbol for solidarity with HIV-positive people and
   those living with AIDS.
   ICD- 10 B 24.
   ICD- 9 042
   DiseasesDB 5938
   MedlinePlus 000594
   eMedicine emerg/253

   Acquired Immune Deficiency Syndrome (AIDS or Aids) is a collection of
   symptoms and infections in humans resulting from the specific damage to
   the immune system caused by the human immunodeficiency virus (HIV). The
   late stage of the condition leaves individuals prone to opportunistic
   infections and tumors. Although treatments for AIDS and HIV exist to
   slow the virus's progression, there is no known cure. HIV is
   transmitted through direct contact of a mucous membrane or the
   bloodstream with a bodily fluid containing HIV, such as blood, semen,
   vaginal fluid, preseminal fluid, and breast milk. This transmission can
   come in the form of anal, vaginal or oral sex, blood transfusion,
   contaminated hypodermic needles, exchange between mother and baby
   during pregnancy, childbirth, or breastfeeding, or other exposure to
   one of the above bodily fluids.

   Most researchers believe that HIV originated in sub-Saharan Africa
   during the twentieth century; it is now a pandemic, with an estimated
   38.6 million people now living with the disease worldwide. As of
   January 2006, the Joint United Nations Programme on HIV/AIDS (UNAIDS)
   and the World Health Organization (WHO) estimate that AIDS has killed
   more than 25 million people since it was first recognized on June 5,
   1981, making it one of the most destructive epidemics in recorded
   history. In 2005 alone, AIDS claimed an estimated 2.4–3.3 million
   lives, of which more than 570,000 were children. A third of these
   deaths are occurring in sub-Saharan Africa, retarding economic growth
   and destroying human capital. Antiretroviral treatment reduces both the
   mortality and the morbidity of HIV infection, but routine access to
   antiretroviral medication is not available in all countries. HIV/AIDS
   stigma is more severe than that associated with other life-threatening
   conditions and extends beyond the disease itself to providers and even
   volunteers involved with the care of people living with HIV.

Infection by HIV

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

   AIDS is the most severe manifestation of infection with HIV. HIV is a
   retrovirus that primarily infects vital components of the human immune
   system such as CD4^+ T cells (a subset of T cells), macrophages and
   dendritic cells. It directly and indirectly destroys CD4^+ T cells.
   CD4^+ T cells are required for the proper functioning of the immune
   system. When HIV kills CD4^+ T cells so that there are fewer than 200
   CD4^+ T cells per microliter (µL) of blood, cellular immunity is lost,
   leading to the condition known as AIDS. Acute HIV infection progresses
   over time to clinical latent HIV infection and then to early
   symptomatic HIV infection and later, to AIDS, which is identified on
   the basis of the amount of CD4^+ T cells in the blood and the presence
   of certain infections.

   In the absence of antiretroviral therapy, the median time of
   progression from HIV infection to AIDS is nine to ten years, and the
   median survival time after developing AIDS is only 9.2 months. However,
   the rate of clinical disease progression varies widely between
   individuals, from two weeks up to 20 years. Many factors affect the
   rate of progression. These include factors that influence the body's
   ability to defend against HIV such as the infected person's general
   immune function. Older people have weaker immune systems, and therefore
   have a greater risk of rapid disease progression than younger people.
   Poor access to health care and the existence of coexisting infections
   such as tuberculosis also may predispose people to faster disease
   progression. The infected person's genetic inheritance plays an
   important role and some people are resistant to certain strains of HIV.
   An example of this is people with the CCR5-Δ32 mutation are resistant
   to infection with certain strains of HIV. HIV is genetically variable
   and exists as different strains, which cause different rates of
   clinical disease progression. The use of highly active antiretroviral
   therapy prolongs both the median time of progression to AIDS and the
   median survival time.

Diagnosis

   Since June 5, 1981, many definitions have been developed for
   epidemiological surveillance such as the Bangui definition and the 1994
   expanded World Health Organization AIDS case definition. However,
   clinical staging of patients was not an intended use for these systems
   as they are neither sensitive, nor specific. In developing countries,
   the World Health Organization staging system for HIV infection and
   disease, using clinical and laboratory data, is used and in developed
   countries, the Centers for Disease Control (CDC) Classification System
   is used.

WHO disease staging system for HIV infection and disease

   In 1990, the World Health Organization (WHO) grouped these infections
   and conditions together by introducing a staging system for patients
   infected with HIV-1. An update took place in September 2005. Most of
   these conditions are opportunistic infections that are easily treatable
   in healthy people.

          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 diarrhea for longer than
          a month, severe bacterial infections and pulmonary tuberculosis
          Stage IV: includes toxoplasmosis of the brain, candidiasis of
          the esophagus, trachea, bronchi or lungs and Kaposi's sarcoma;
          these diseases are indicators of AIDS.

CDC classification system for HIV infection

   The Centers for Disease Control and Prevention (CDC) originally
   classified AIDS as GRID which stood for Gay Related Immune Disease.
   However, after determining that AIDS is not isolated to homosexual
   people the name was changed to the neutral AIDS. In 1993, the CDC
   expanded their definition of AIDS to include all HIV positive people
   with a CD4^+ T cell count below 200 per µL of blood or 14% of all
   lymphocytes. The majority of new AIDS cases in developed countries use
   either this definition or the pre-1993 CDC definition. The AIDS
   diagnosis still stands even if, after treatment, the CD4^+ T cell count
   rises to above 200 per µL of blood or other AIDS-defining illnesses are
   cured.

HIV test

   Many people are unaware that they are infected with HIV. Less than 1%
   of the sexually active urban population in Africa has been tested, and
   this proportion is even lower in rural populations. Furthermore, only
   0.5% of pregnant women attending urban health facilities are counseled,
   tested or receive their test results. Again, this proportion is even
   lower in rural health facilities. Therefore, donor blood and blood
   products used in medicine and medical research are screened for HIV.
   Typical HIV tests, including the HIV enzyme immunoassay and the Western
   blot assay, detect HIV antibodies in serum, plasma, oral fluid, dried
   blood spot or urine of patients. However, the window period (the time
   between initial infection and the development of detectable antibodies
   against the infection) can vary. This is why it can take 3-6 months to
   seroconvert and test positive. Commercially available tests to detect
   other HIV antigens, HIV- RNA, and HIV-DNA in order to detect HIV
   infection prior to the development of detectable antibodies are
   available. For the diagnosis of HIV infection these assays are not
   specifically approved, but are nonetheless routinely used in developed
   countries.

Symptoms and complications

   A generalized graph of the relationship between HIV copies (viral load)
   and CD4 counts over the average course of untreated HIV infection; any
   particular individual's disease course may vary considerably.  CD4+ T
   Lymphocyte count (cells/mm³)  HIV RNA copies per mL of plasma
   Enlarge
   A generalized graph of the relationship between HIV copies (viral load)
   and CD4 counts over the average course of untreated HIV infection; any
   particular individual's disease course may vary considerably.

   CD4^+ T Lymphocyte count (cells/mm³)

   HIV RNA copies per mL of plasma

   The symptoms of AIDS are primarily the result of conditions that do not
   normally develop in individuals with healthy immune systems. Most of
   these conditions are infections caused by bacteria, viruses, fungi and
   parasites that are normally controlled by the elements of the immune
   system that HIV damages. Opportunistic infections are common in people
   with AIDS. HIV affects nearly every organ system. People with AIDS also
   have an increased risk of developing various cancers such as Kaposi's
   sarcoma, cervical cancer and cancers of the immune system known as
   lymphomas.

   Additionally, people with AIDS often have systemic symptoms of
   infection like fevers, sweats (particularly at night), swollen glands,
   chills, weakness, and weight loss. After the diagnosis of AIDS is made,
   the current average survival time with antiretroviral therapy ( as of
   2005) is estimated to be more than 5 years, but because new treatments
   continue to be developed and because HIV continues to evolve resistance
   to treatments, estimates of survival time are likely to continue to
   change. Without antiretroviral therapy, death normally occurs within a
   year. Most patients die from opportunistic infections or malignancies
   associated with the progressive failure of the immune system.

   The rate of clinical disease progression varies widely between
   individuals and has been shown to be affected by many factors such as
   host susceptibility and immune function health care and co-infections,
   as well as factors relating to the viral strain. The specific
   opportunistic infections that AIDS patients develop depend in part on
   the prevalence of these infections in the geographic area in which the
   patient lives.

Major pulmonary illnesses

   X-ray of Pneumocystis jiroveci pneumonia There is increased white
   (opacity) in the lower lungs on both sides, characteristic of
   Pneumocystis pneumonia
   Enlarge
   X-ray of Pneumocystis jiroveci pneumonia There is increased white
   (opacity) in the lower lungs on both sides, characteristic of
   Pneumocystis pneumonia
     * Pneumocystis jiroveci pneumonia (originally known as Pneumocystis
       carinii pneumonia, often-abbreviated PCP) is relatively rare in
       healthy, immunocompetent people, but common among HIV-infected
       individuals. Before the advent of effective diagnosis, treatment
       and routine prophylaxis in Western countries, it was a common
       immediate cause of death. In developing countries, it is still one
       of the first indications of AIDS in untested individuals, although
       it does not generally occur unless the CD4 count is less than 200
       per µL.
     * Tuberculosis (TB) is unique among infections associated with HIV
       because it is transmissible to immunocompetent people via the
       respiratory route, is easily treatable once identified, may occur
       in early-stage HIV disease, and is preventable with drug therapy.
       However, multidrug resistance is a potentially serious problem.
       Even though its incidence has declined because of the use of
       directly observed therapy and other improved practices in Western
       countries, this is not the case in developing countries where HIV
       is most prevalent. In early-stage HIV infection (CD4 count >300
       cells per µL), TB typically presents as a pulmonary disease. In
       advanced HIV infection, TB often presents atypically with
       extrapulmonary (systemic) disease a common feature. Symptoms are
       usually constitutional and are not localized to one particular
       site, often affecting bone marrow, bone, urinary and
       gastrointestinal tracts, liver, regional lymph nodes, and the
       central nervous system. Alternatively, symptoms may relate more to
       the site of extrapulmonary involvement.

Major gastro-intestinal illnesses

     * Esophagitis is an inflammation of the lining of the lower end of
       the esophagus (gullet or swallowing tube leading to the stomach).
       In HIV infected individuals, this is normally due to fungal (
       candidiasis) or viral ( herpes simplex-1 or cytomegalovirus)
       infections. In rare cases, it could be due to mycobacteria.
     * Unexplained chronic diarrhea in HIV infection is due to many
       possible causes, including common bacterial ( Salmonella, Shigella,
       Listeria, Campylobacter, or Escherichia coli) and parasitic
       infections, and uncommon opportunistic infections such as
       cryptosporidiosis, microsporidiosis, Mycobacterium avium complex
       (MAC) and cytomegalovirus (CMV) colitis. In some cases, diarrhea
       may be a side effect of several drugs used to treat HIV, or it may
       simply accompany HIV infection, particularly during primary HIV
       infection. It may also be a side effect of antibiotics used to
       treat bacterial causes of diarrhea (common for Clostridium
       difficile). In the later stages of HIV infection, diarrhea is
       thought to be a reflection of changes in the way the intestinal
       tract absorbs nutrients, and may be an important component of
       HIV-related wasting.

Major neurological illnesses

     * Toxoplasmosis is a disease caused by the single-celled parasite
       called Toxoplasma gondii; it usually infects the brain causing
       toxoplasma encephalitis but it can infect and cause disease in the
       eyes and lungs.
     * Progressive multifocal leukoencephalopathy (PML) is a demyelinating
       disease, in which the gradual destruction of the myelin sheath
       covering the axons of nerve cells impairs the transmission of nerve
       impulses. It is caused by a virus called JC virus which occurs in
       70% of the population in latent form, causing disease only when the
       immune system has been severely weakened, as is the case for AIDS
       patients. It progresses rapidly, usually causing death within
       months of diagnosis.
     * AIDS dementia complex (ADC) is a metabolic encephalopathy induced
       by HIV infection and fuelled by immune activation of HIV infected
       brain macrophages and microglia which secrete neurotoxins of both
       host and viral origin. Specific neurological impairments are
       manifested by cognitive, behavioural, and motor abnormalities that
       occur after years of HIV infection and is associated with low CD4^+
       T cell levels and high plasma viral loads. Prevalence is 10-20% in
       Western countries but only 1-2% of HIV infections in India. This
       difference is possibly due to the HIV subtype in India.
     * Cryptococcal meningitis is an infection of the meninx (the membrane
       covering the brain and spinal cord) by the fungus Cryptococcus
       neoformans. It can cause fevers, headache, fatigue, nausea, and
       vomiting. Patients may also develop seizures and confusion; left
       untreated, it can be lethal.

Major HIV-associated malignancies

   Kaposi's sarcoma
   Enlarge
   Kaposi's sarcoma

   Patients with HIV infection have substantially increased incidence of
   several malignant cancers. This is primarily due to co-infection with
   an oncogenic DNA virus, especially Epstein-Barr virus (EBV), Kaposi's
   sarcoma-associated herpesvirus (KSHV), and human papillomavirus (HPV).
   The following confer a diagnosis of AIDS when they occur in an
   HIV-infected person.
     * Kaposi's sarcoma (KS) is the most common tumor in HIV-infected
       patients. The appearance of this tumor in young homosexual men in
       1981 was one of the first signals of the AIDS epidemic. Caused by a
       gammaherpes virus called Kaposi's sarcoma-associated herpes virus
       (KSHV), it often appears as purplish nodules on the skin, but can
       affect other organs, especially the mouth, gastrointestinal tract,
       and lungs.
     * High-grade B cell lymphomas such as Burkitt's lymphoma,
       Burkitt's-like lymphoma, diffuse large B-cell lymphoma (DLBCL), and
       primary central nervous system lymphoma present more often in
       HIV-infected patients. These particular cancers often foreshadow a
       poor prognosis. In some cases these lymphomas are AIDS-defining.
       Epstein-Barr virus (EBV) or KSHV cause many of these lymphomas.
     * Cervical cancer in HIV-infected women is considered AIDS-defining.
       It is caused by human papillomavirus (HPV).

   In addition to the AIDS-defining tumors listed above, HIV-infected
   patients are at increased risk of certain other tumors, such as
   Hodgkin's disease and anal and rectal carcinomas. However, the
   incidence of many common tumors, such as breast cancer or colon cancer,
   does not increase in HIV-infected patients. In areas where HAART is
   extensively used to treat AIDS, the incidence of many AIDS-related
   malignancies has decreased, but at the same time malignant cancers
   overall have become the most common cause of death of HIV-infected
   patients.

Other opportunistic infections

   AIDS patients often develop opportunistic infections that present with
   non-specific symptoms, especially low-grade fevers and weight loss.
   These include infection with Mycobacterium avium-intracellulare and
   cytomegalovirus (CMV). CMV can cause colitis, as described above, and
   CMV retinitis can cause blindness. Penicilliosis due to Penicillium
   marneffei is now the third most common opportunistic infection (after
   extrapulmonary tuberculosis and cryptococcosis) in HIV-positive
   individuals within the endemic area of Southeast Asia.

Treatment

   There is currently no vaccine or cure for HIV or AIDS. The only known
   methods of prevention are based on avoiding exposure to the virus or,
   failing that, an antiretroviral treatment directly after a highly
   significant exposure, called post-exposure prophylaxis (PEP). PEP has a
   very demanding four week schedule of dosage. It also has very
   unpleasant side effects including diarrhea, malaise, nausea and
   fatigue.

   Current treatment for HIV infection consists of highly active
   antiretroviral therapy, or HAART. This has been highly beneficial to
   many HIV-infected individuals since its introduction in 1996 when the
   protease inhibitor-based HAART initially became available. Current
   optimal HAART options consist of combinations (or "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 (NARTIs or NRTIs)
   plus either a protease inhibitor or a non-nucleoside reverse
   transcriptase inhibitor (NNRTI). Because HIV disease progression in
   children is more rapid than in adults, and laboratory parameters are
   less predictive of risk for disease progression, particularly for young
   infants, treatment recommendations are more aggressive for children
   than for adults. In developed countries where HAART is available,
   doctors assess the viral load, rapidity in CD4 decline, and patient
   readiness while deciding when to recommend initiating treatment.
   Abacavir - a nucleoside analog reverse transcriptase inhibitors (NARTIs
   or NRTIs)
   Enlarge
   Abacavir - a nucleoside analog reverse transcriptase inhibitors (NARTIs
   or NRTIs)
   Atazanavir - a protease inhibitor
   Enlarge
   Atazanavir - a protease inhibitor

   HAART allows the stabilisation of the patient’s symptoms and viremia,
   but it neither cures the patient of HIV, nor alleviates the symptoms,
   and high levels of HIV-1, often HAART resistant, return once treatment
   is stopped. Moreover, it would take more than the lifetime of an
   individual to be cleared of HIV infection using HAART. Despite this,
   many HIV-infected individuals have experienced remarkable improvements
   in their general health and quality of life, which has led to the
   plummeting of HIV-associated morbidity and mortality. In the absence of
   HAART, progression from HIV infection to AIDS occurs at a median of
   between nine to ten years and the median survival time after developing
   AIDS is only 9.2 months. Still, for some patients - and in many
   clinical cohorts this may be more than fifty percent of patients -
   HAART achieves far less than optimal results. This is due to a variety
   of reasons such as medication intolerance/side effects, prior
   ineffective antiretroviral therapy and infection with a drug-resistant
   strain of HIV. However, non-adherence and non-persistence with
   antiretroviral therapy is the major reason most individuals fail to get
   any benefit from and develop resistance to HAART. The reasons for
   non-adherence and non-persistence with HAART are varied and
   overlapping. Major psychosocial issues, such as poor access to medical
   care, inadequate social supports, psychiatric disease and drug abuse
   contribute to non-adherence. The complexity of these HAART regimens,
   whether due to pill number, dosing frequency, meal restrictions or
   other issues along with side effects that create intentional
   non-adherence also has a weighty impact. The side effects include
   lipodystrophy, dyslipidaemia, insulin resistance, an increase in
   cardiovascular risks and birth defects.

   Anti-retroviral drugs are expensive, 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, further simplifying drug
   regimens to improve adherence, and determining the best sequence of
   regimens to manage drug resistance. Only a vaccine is postulated to be
   able to halt the pandemic. This is because a vaccine would possibly
   cost less, thus being affordable for developing countries, and would
   not require daily treatments. However, after over 20 years of research,
   HIV-1 remains a difficult target for a vaccine.

   A number of studies have shown that measures to prevent opportunistic
   infections can be beneficial when treating patients with HIV infection
   or AIDS. Vaccination against hepatitis A and B is advised for patients
   who are not infected with these viruses and are at risk of becoming
   infected. In addition, AIDS patients should receive vaccination against
   Streptococcus pneumoniae and should receive yearly vaccination against
   influenza virus. Patients with substantial immunosuppression are also
   advised to receive prophylactic therapy for Pneumocystis jiroveci
   pneumonia (PCP), and many patients may benefit from prophylactic
   therapy for toxoplasmosis and Cryptococcus meningitis.

   Various forms of alternative medicine have been used to try to treat
   symptoms or to try to affect the course of the disease itself, although
   none is a substitute for conventional treatment. 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. The definition of "alternative therapies" in AIDS has
   changed since that time. Then, the phrase often referred to
   community-driven treatments, untested by government or pharmaceutical
   company research, that some hoped would directly suppress the virus or
   stimulate immunity against it. These kinds of approaches have become
   less common over time as the benefits of AIDS drugs have become more
   apparent. Examples of alternative medicine that people hoped would
   improve their symptoms or their quality of life include massage, herbal
   and flower remedies and acupuncture; when used with conventional
   treatment, many now refer to these as "complementary" approaches. None
   of these treatments has been proven in controlled trials to have any
   effect in treating HIV or AIDS directly. However, some may improve
   feelings of well-being in people who believe in their value.
   Additionally, people with AIDS, like people with other illnesses such
   as cancer, sometimes use marijuana to treat pain, combat nausea and
   stimulate appetite.

Epidemiology

   Prevalence of HIV among adults per country at the end of 2005 ██ 15-50%
   ██ 5-15% ██ 1-5% ██ 0.5-1.0% ██ 0.1-0.5% ██ <0.1% ██ no data
   Enlarge
   Prevalence of HIV among adults per country at the end of 2005 ██ 15-50%
   ██ 5-15% ██ 1-5% ██ 0.5-1.0% ██ 0.1-0.5% ██ <0.1% ██ no data

   UNAIDS and the WHO estimate that AIDS has killed more than 25 million
   people since it was first recognized in 1981, making it one of the most
   destructive epidemics in recorded history. Despite recent, improved
   access to antiretroviral treatment and care in many regions of the
   world, the AIDS epidemic claimed an estimated 2.8 million (between 2.4
   and 3.3 million) lives in 2005 of which more than half a million
   (570,000) were children.

   Globally, between 33.4 and 46 million people currently live with HIV.
   In 2005, between 3.4 and 6.2 million people were newly infected and
   between 2.4 and 3.3 million people with AIDS died, an increase from
   2003 and the highest number since 1981.

   Sub-Saharan Africa remains by far the worst affected region, with an
   estimated 21.6 to 27.4 million people currently living with HIV. Two
   million [1.5–3.0 million] of them are children younger than 15 years of
   age. More than 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. In 2005, there were 12.0 million [10.6–13.6 million] AIDS orphans
   living in sub-Saharan Africa 2005. South & South East Asia are second
   worst affected with 15%. AIDS accounts for the deaths of 500,000
   children in this region. Two-thirds of HIV/AIDS infections in Asia
   occur in India, with an estimated 5.7 million infections (estimated 3.4
   - 9.4 million) (0.9% of population), surpassing South Africa's
   estimated 5.5 million (4.9-6.1 million) (11.9% of population)
   infections, making it the country with the highest number of HIV
   infections in the world. In the 35 African nations with the highest
   prevalence, average life expectancy is 48.3 years— 6.5 years less than
   it would be without the disease.

   The latest evaluation report of the World Bank's Operations Evaluation
   Department assesses the effectiveness of the World Bank's country-level
   HIV/AIDS assistance, defined as policy dialogue, analytic work, and
   lending, with the explicit objective of reducing the scope or impact of
   the AIDS epidemic. This is the first comprehensive evaluation of the
   World Bank's HIV/AIDS support to countries, from the beginning of the
   epidemic through mid-2004. Because the Bank's assistance is for
   implementation of government programs by government, it provides
   important insights on how national AIDS programs can be made more
   effective.

   The development of HAART as effective therapy for HIV infection and
   AIDS has substantially reduced the death rate from this disease in
   those areas where it is widely available. This has created the
   misperception that the disease has gone away. In fact, as the life
   expectancy of persons with AIDS has increased in countries where HAART
   is widely used, the number of persons living with AIDS has increased
   substantially. In the United States, the number of persons with AIDS
   increased from about 35,000 in 1988 to over 220,000 in 1996.

   In Africa, the number of MTCT and the prevalence of AIDS is beginning
   to reverse decades of steady progress in child survival. Countries such
   as Uganda are attempting to curb the MTCT epidemic by offering VCT
   (voluntary counseling and testing), PMTCT (prevention of
   mother-to-child transmission) and ANC (ante-natal care) services, which
   include the distribution of antiretroviral therapy.

Economic impact

   Changes in life expectancy in some hard-hit African countries.
   Botswana Zimbabwe Kenya South Africa Uganda
   Enlarge
   Changes in life expectancy in some hard-hit African countries.

   Botswana

   Zimbabwe

   Kenya

   South Africa

   Uganda

   HIV and AIDS retard economic growth by destroying human capital. UNAIDS
   has predicted outcomes for sub-Saharan Africa to the year 2025. These
   range from a plateau and eventual decline in deaths beginning around
   2012 to a catastrophic continual growth in the death rate with
   potentially 90 million cases of infection.

   Without proper nutrition, health care and medicine that is available in
   developed countries, large numbers of people in these countries are
   falling victim to AIDS. They will not only be unable to work, but will
   also require significant medical care. The forecast is that this will
   likely cause a collapse of economies and societies in the region. In
   some heavily infected areas, the epidemic has left behind many orphans
   cared for by elderly grandparents.

   The increased mortality in this region will result in a smaller skilled
   population and labor force. This smaller labor force will be
   predominantly young people, with reduced knowledge and work experience
   leading to reduced productivity. An increase in workers’ time off to
   look after sick family members or for sick leave will also lower
   productivity. Increased mortality will also weaken the mechanisms that
   generate human capital and investment in people, through loss of income
   and the death of parents. By killing off mainly young adults, AIDS
   seriously weakens the taxable population, reducing the resources
   available for public expenditures such as education and health services
   not related to AIDS resulting in increasing pressure for the state's
   finances and slower growth of the economy. This results in a slower
   growth of the tax base, an effect that will be reinforced if there are
   growing expenditures on treating the sick, training (to replace sick
   workers), sick pay and caring for AIDS orphans. This is especially true
   if the sharp increase in adult mortality shifts the responsibility and
   blame from the family to the government in caring for these orphans.

   On the level of the household, AIDS results in both the loss of income
   and increased spending on healthcare by the household. The income
   effects of this lead to spending reduction as well as a substitution
   effect away from education and towards healthcare and funeral spending.
   A study in Côte d'Ivoire showed that households with an HIV/AIDS
   patient spent twice as much on medical expenses as other households.

   UNAIDS, WHO and the United Nations Development Programme have
   documented a correlation between the decreasing life expectancies and
   the lowering of gross national product in many African countries with
   prevalence rates of 10% or more. Indeed, since 1992 predictions that
   AIDS would slow economic growth in these countries have been published.
   The degree of impact depended on assumptions about the extent to which
   illness would be funded by savings and who would be infected.
   Conclusions reached from models of the growth trajectories of 30
   sub-Saharan economies over the period 1990–2025 were that the economic
   growth rates of these countries would be between 0.56 and 1.47% lower.
   The impact on gross domestic product (GDP) per capita was less
   conclusive. However, in 2000, the rate of growth of Africa's per capita
   GDP was in fact reduced by 0.7% per year from 1990–1997 with a further
   0.3% per year lower in countries also affected by malaria. The forecast
   now is that the growth of GDP for these countries will undergo a
   further reduction of between 0.5 and 2.6% per annum. However, these
   estimates may be an underestimate, as they do not look at the effects
   on output per capita.

   Many governments in sub-Saharan Africa denied that there was a problem
   for years, and are only now starting to work towards solutions.
   Underfunding is a problem in all areas of HIV prevention when compared
   to even conservative estimates of the problems.

   The launching of the world's first official HIV/AIDS Toolkit in
   Zimbabwe on October 3, 2006 is a product of collaborative work between
   the International Federation of Red Cross and Red Crescent Societies,
   World Health Organization and the Southern Africa HIV/AIDS Information
   Dissemination Service. It is for the strengthening of people living
   with HIV/AIDS and nurses by minimal external support. The package,
   which is in form of eight modules focusing on basic facts about HIV and
   AIDS, was pre-tested in Zimbabwe in March 2006 to determine its
   adaptability. It disposes, among other things, categorized guidelines
   on clinical management, education and counseling of AIDS victims at
   community level.

   The Copenhagen Consensus is a project that seeks to establish
   priorities for advancing global welfare using methodologies based on
   the theory of welfare economics. The participants are all economists,
   with the focus of the project being a rational prioritization based on
   economic analysis. The project is based on the contention that, in
   spite of the billions of dollars spent on global challenges by the
   United Nations, the governments of wealthy nations, foundations,
   charities, and non-governmental organizations, the money spent on
   problems such as malnutrition and climate change is not sufficient to
   meet many internationally-agreed targets. The highest priority was
   assigned to implementing new measures to prevent the spread of HIV and
   AIDS. The economists estimated that an investment of $27 billion could
   avert nearly 30 million new infections by 2010.

Stigma

   AIDS stigma exists around the world in a variety of ways, including
   ostracism, rejection, discrimination and avoidance of HIV infected
   people; compulsory HIV testing without prior consent or protection of
   confidentiality; violence against HIV infected individuals or people
   who are perceived to be infected with HIV; and the quarantine of HIV
   infected individuals.

   AIDS stigma has been further divided into the following three
   categories:
    1. Instrumental AIDS stigma—a reflection of the fear and apprehension
       that are likely to be associated with any deadly and transmissible
       illness.
    2. Symbolic AIDS stigma—the use of HIV/AIDS to express attitudes
       toward the social groups or lifestyles perceived to be associated
       with the disease.
    3. Courtesy AIDS stigma—stigmatization of people connected to the
       issue of HIV/AIDS or HIV- positive people.

   Often, AIDS stigma is expressed in conjunction with one or more other
   stigmas, particularly those associated with homosexuality, bisexuality,
   and intravenous drug use.

   In many developed countries, there is an association between AIDS and
   homosexuality or bisexuality, and this association is correlated with
   higher levels of sexual prejudice such as anti-homosexual attitudes.
   There is also a perceived association between all male-male sexual
   behaviour and AIDS, even sex between two uninfected men.

          For more details on this topic, see Stigma and HIV-AIDS, A
          review of the literature

Origin of HIV

   AIDS was first reported June 5, 1981, when the U.S. Centers for Disease
   Control and Prevention recorded a cluster of Pneumocystis carinii
   pneumonia (now classified as Pneumocystis jiroveci pneumonia) in five
   homosexual men in Los Angeles. Originally dubbed GRID, or Gay-Related
   Immune Deficiency, health authorities soon realized that nearly half of
   the people identified with the syndrome were not homosexual men. 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 the Congo.
    2. HIV found in tissue samples from a 15 year old African-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 not as
   easily transmitted and is largely confined to West Africa. Both HIV-1
   and HIV-2 are of primate origin. The origin of HIV-1 is the Central
   Common Chimpanzee (Pan troglodytes troglodytes) found in southern
   Cameroon. It is established that HIV-2 originated from the Sooty
   Mangabey (Cercocebus atys), an Old World monkey of Guinea Bissau,
   Gabon, and Cameroon.

   Most experts believe that HIV probably transferred to humans as a
   result of direct contact with primates, for instance during hunting or
   butchery. A more controversial theory known as the OPV AIDS hypothesis
   suggests that the AIDS epidemic was inadvertently started in the late
   1950s in the Belgian Congo by Hilary Koprowski's research into a polio
   vaccine. According to scientific consensus, this scenario is not
   supported by the available evidence.

Alternative hypotheses

   A small minority of scientists and activists question the connection
   between HIV and AIDS, the existence of HIV itself, or the validity of
   current testing and treatment methods. These claims are considered
   baseless by the vast majority of the scientific community. The medical
   community argues that so-called "AIDS dissidents" selectively ignore
   evidence in favour of HIV's role in AIDS and irresponsibly pose a
   threat to public health by discouraging HIV testing and proven
   treatments.

   AIDS 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. Dissident views have been widely rejected, and are considered
   pseudoscience by the mainstream scientific community.

Common misconceptions

   A number of misconceptions have arisen surrounding HIV/AIDS. Three of
   the most common are that AIDS can spread through casual contact, sexual
   intercourse with a virgin will cure AIDS, and HIV can infect only
   homosexual men and drug users.

   When scientists first recognized the syndrome in 1981 initially they
   termed it Gay Related Immune Deficiency Syndrome, a possible source for
   the misconception holding that AIDS infects only homosexual men;
   scientists soon renamed the disease in recognition of transmission
   other than by male-male intercourse.

   HIV appears to have entered the United States around the late 1960s and
   seems to have then been unknowingly spread by people throughout the
   U.S. and Europe. In a survey on AIDS conducted in 1983 in Belgium,
   Denmark, Finland, France, Germany, Italy, the Netherlands, Norway,
   Sweden, Switzerland, and the United Kingdom a majority of those
   infected with HIV were male homosexuals (58% of all cases).
   Retrieved from " http://en.wikipedia.org/wiki/AIDS"
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