Human immunodeficiency virus has affected individuals worldwide since it first caused rare illnesses in a select group of individuals in 1980

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HIV/AIDS Overview

Introduction

Human immunodeficiency virus has affected individuals worldwide since it first caused rare illnesses in a select group of individuals in 1980.1 First identified in 1983, human immunodeficiency virus (HIV) quickly spread, eventually becoming a worldwide pandemic. It has been estimated that approximately forty million people worldwide live with HIV,4 and one million of those with HIV reside in the United States. The disease had a significant impact on Africa, with the numbers peaking at 2.3 million in 2010. By 1983, HIV was discovered as the cause of a number of rare cases of Kaposi’s sarcoma and pneumocystis pneumonia in otherwise healthy individuals.2 In the first decade, the disease spread rapidly, destroying the immune systems of those infected. Health clinicians must understand the signs and symptoms of infection, as well as the various stages of HIV infection.


Overview Of Human Immunodeficiency Virus

Since it was first discovered, HIV has become a worldwide pandemic.3 Initially, HIV was considered a homosexual disease, but it was soon discovered to be a virus that infected anyone, regardless of race, sexual orientation, or socioeconomic status.5 HIV attacks, and eventually destroys, the immune system. During the early stages of infection, individuals can live symptom free.6 Progression of the disease varies by patient and can be impacted by a variety of factors. In the stage of the infection known as HIV, patients often exhibit few symptoms. When the disease transitions to acquired immune deficiency syndrome (AIDS) the patient often experiences an increase in symptoms and severity of the disease and presents with one or more opportunistic infections.7,8

Origin of HIV

When HIV emerged in the early 1980s scientists began trying to determine its origins. After years of research, scientists traced the virus to chimpanzees in Africa.9 These chimpanzees were infected with simian immunodeficiency virus (SIV), which is a retrovirus similar to HIV.9 While HIV did not spread significantly into the human population until the 1980s, evidence shows that SIV may have infected humans as early as 1884.10 While there are no documented cases of HIV from that time period, scientists did discover a documented case of HIV posthumously in a fifteen-year-old black male who died in 1968.11 There are various theories as to why the virus did not spread in earlier populations, but there is no definitive answer as to why. Regardless, something caused the virus to spread in the 1980’s, resulting in the pandemic that has affected society for the past decades.

Although there is evidence that HIV may have infected humans as early as 1884, the subtype of the virus that currently infects individuals has been traced to a more recent time period. Research shows that HIV most likely spread to humans at three different points in history, one for each subtype of HIV-1 (M, N, and O).12 The most common strain of HIV-1, the type that infects most patients today, is believed to have been transmitted by the Cameroon chimps to humans in the period shortly before 1931.10 This conclusion was made after extensive research, which examined the virus in samples of infected tissue that was collected over the past three decades. Upon examination of these samples, it was determined that an ancestral form of HIV started to spread in the human population approximately 75 years prior.13 Therefore, it is assumed that the transmission from chimpanzees to humans occurred shortly before that.


History of HIV Development

In June of 1981, the Centers for Disease Control and Prevention (CDC) reported on five individual cases of a rare lung infection, Pneumocystis carinii pneumonia (PCP).14 All five individuals were homosexual men living in Los Angeles, and each patient had been healthy prior to the onset of infection. Upon further examination, it was determined that all five men were experiencing other illnesses as well.14 When the CDC report was released, other medical clinicians submitted reports of similar cases nationwide. In all cases, patients had been previously healthy and were presenting with similar infections.2 Among the infections were reports of a rare form of cancer, Kaposi’s sarcoma.1,5 A task force was formed to study the incidence of infections and to determine common causes among the patients.3 In 1981, there were 270 cases reported with 121 deaths.15 By 1982, there were a total of 452 reported cases from 23 states.15

In the two years following the first reported cases, various initiatives were established to assist with the identification, management and care of the unknown disease. Initially, the disease was thought to be specific to homosexual men.5 In fact, in the beginning, many individuals referred to the disease as GRID (Homosexual-Related Immune Deficiency).16 While the virus was originally thought to be a disease only affecting homosexual men, it was soon discovered in other individuals, especially those who had received blood transfusions.17,18 In 1982, the term Acquired Immune Deficiency Syndrome (AIDS) was used to define the syndrome that was affecting individuals throughout the country.19 Care centers were established to help the tens of thousands of patients who were infected with the disease.16

By 1983, the CDC was able to identify the specific transmission modes of the disease as through sexual contact and exposure to blood and blood-borne pathogens.20 The CDC also discovered that the disease had infected homosexual men, women with male partners, infants and injection drug users.15 As a result, a public statement was released warning individuals to refrain from activities that would put them in contact with the disease.20 Scientists in France identified the specific virus strain suspected to be causing AIDS as Lymphadenopathy Associated Virus (LAV),21 while scientists in the United States identified the virus as the retrovirus HTLV-III.22 After comparing the findings, it was determined that the two strains were almost identical. It was also determined that they were most likely the cause of AIDS.10

In 1985, the viral strain became known as Human Immunodeficiency Virus and was identified as the cause of AIDS.10 As a result, the CDC redefined the AIDS clinical definition to include HIV as the cause of the infection. Acquired Immune Deficiency Syndrome was determined to be an end result of HIV infection.3 While the disease is considered to have started in 1980, it is now understood that it must have originated years earlier as an individual can live for many years with HIV before progressing to the stage of AIDS.13
In the years following the discovery of HIV, significant research focused on identifying the origin and causes of the virus, developing treatment, and attempting to find a cure.23 In the late 1980s and throughout the 1990s, when the virus reached its peak, numerous organizations were founded to address the needs of those living with HIV and to help prevent the spread of the infection.3 During this time, the stigma associated with the virus impacted how people viewed and interacted with HIV positive individuals and educational campaigns aimed at eliminating the stigma were introduced.16 Social service and case management programs were developed to address non-HIV issues in patients and training for healthcare clinicians focused on the effective treatment and management of the virus.16

Since the first reported case of AIDS the disease spread and grew to significant numbers.10 Human immunodeficiency virus has impacted individuals throughout the world and has resulted in a worldwide pandemic which required myriad initiatives to help infected individuals live with the disease and also to minimize the spread of the infection. However, by the early 2000s, public knowledge of the virus had increased. Due to educational programming and patient treatment strategies, the number of new cases began to decrease.24 In addition, HIV positive individuals began to live longer and remained relatively symptom-free for extended periods of time.6 Human immunodeficiency virus treatment strategies evolved and a multifaceted approach to disease management became standard protocol for working with HIV positive patients.25

Epidemiology Of HIV

Over the past decades, HIV has become a worldwide pandemic. Since the epidemic began, approximately sixty million people worldwide have contracted the disease.26 Currently, there are approximately forty million people living with HIV. Of those, one million reside in the United States.4 Approximately 3 million of the current HIV cases are in individuals under the age of fifteen.27 Since 1995, HIV has been one of the leading causes of death in persons age 25 to 44.28 The total number of deaths since the virus was first reported total approximately thirty million worldwide.26


Global Impact

While the epidemic has had a significant impact on the United States, its impact has been even greater worldwide, with the most significant numbers occurring in Sub-Saharan Africa.26 More than two-thirds of the reported cases of HIV are in individuals living in Sub-Saharan Africa.29 Since the disease began spreading, it has utterly devastated the country, with the number of reported cases peaking at 2.3 million.30 Due to the lack of adequate care and prevention measures, the transmission rate of HIV in Sub-Saharan Africa is greater than in other areas.26

The World Health Organization (WHO) monitors the disease on a global scale, and reports are issued annually which provide detailed statistics on the number of reported cases globally and by nation. According to the WHO, 34.0 million (31.4–35.9 million) people globally were living with HIV at the end of 2011. An estimated 0.8% of adults aged 15 to 49 years worldwide are living with HIV, although the burden of the epidemic continues to vary considerably between countries and regions. Sub-Saharan Africa remains most severely affected, with nearly 1 in every 20 adults (4.9%) living with HIV and accounting for 69% of the people living with HIV worldwide.29

While HIV has affected individuals on a global scale, the disease has been reported as most prevalent in Sub-Saharan Africa, where 69% of the population is currently HIV positive.26 HIV was reported to also be the leading cause of death in Africa. This region had the highest percentage of children who are HIV positive, which is 94%. In nine countries in this region, at least 10% or more of the population is HIV positive, and all the nations in the region have generalized HIV epidemics.31 The highest numbers of people worldwide who are HIV positive reside in South Africa, and Swaziland had the highest overall prevalence rate, reported as 26%. The remaining HIV cases were spread throughout the world, with a high concentration of cases in low and middle-income countries.32 International and national organizations responding to the HIV epidemic supported health team efforts to provide education and health aid to high-risk areas, such as the U.S. Peace Corps as well as other Africa and interurban initiatives.


HIV Prevalence & Incidence by Region

Region

Total No. (%) Living with HIV in 2011

Newly Infected in 2011

Adult Prevalence Rate 2011


Global Total

34.0 million (100%)

2.5 million

0.8%

Sub-Saharan Africa

23.5 million (69%)

1.8 million

4.9%

South/South-East Asia

4.0 million (12%)

280,000

0.3%

Eastern Europe/Central Asia

1.4 million (4%)

140,000

1.0%

Latin America

1.4 million (4%)

86,000

0.4%

North America


1.4 million (4%)

51,000

0.6%

Western/Central Europe

900,000 (3%)

30,000

0.2%

East Asia

830,000 (2%)

89,000

0.1%

Middle East/North Africa

300,000 (1%)

37,000

0.2%

Caribbean

230,000 (0.7%)

13,000

1.0%

Oceania

53,000 (0.2%)

2,900

0.3%

Since 2001, the number of new HIV infections has decreased by more than 20%.26 In low and middle-income countries, the rate of infection has declined by more than 50%.30 However, even with a decline, there are still new cases reported each year, and the risk of infection in low and middle-income countries is still high. In 2011, there were 2.5 million new infections reported, and 1.8 million of the infections were in Sub-Saharan Africa.32

Between the years 2010 to 2014, the rate of HIV infection diagnosed for persons aged 25–29 years reportedly increased. The rates for children (aged less than 13 years) and persons aged 13–14, 15–19, 35–39, 40–44, 45– 49, 50–54, 55–59, and 60–64 years were reported decreased. The rates of HIV infection for persons aged 20–24, 30–34, and 65 years and older remained stable. In 2014, the highest rate of diagnosed HIV infection was for persons aged 25–29 years, followed by the rate for persons aged 20– 24 years.32 Young women are two times more likely to test positive for HIV than men of the same age.26 The virus also significantly impacts children under the age of fifteen. In 2011, there were 3.3 million children worldwide who tested positive for HIV.33 There are many international health organizations, such as UNICEF, World Camp for Kids, Save the Children, and others supporting volunteer efforts for children with HIV infections and AIDS.
National Impact

To properly track the HIV epidemic in the United States, reporting of the virus has been required throughout the country since shortly after the virus was discovered.24 From 1981 through 1995, the virus spread rapidly, and although antiretroviral treatment helped reduce the number of cases, the virus peaked in the United States in the period from 1993 to 1995.28 By 1989, the number of reported cases in the United States reached 100,000, and by 1995 the numbers had exceeded half a million.28

To accurately measure the impact of the virus in the United States, the CDC collects information about each reported HIV case. This information is compiled into surveillance reports that explain how and where the virus has spread. The reports examine factors such as risk group, age, gender, status, and geographic location to analyze trends in viral spread and progression.

The most recent HIV Surveillance Report, released in 2014 by the CDC, provided information on the period from 2010 to 2014. While the report itself is very detailed and includes extensive information on the epidemiology of the virus, the CDC also releases brief reports that summarize the information and provide basic trend information based on risk group. The following is the CDC’s most recent summary of HIV trends from 2010 through 2014.32
HIV Incidence (New Infections)

The estimated incidence of HIV has remained stable overall in recent years. During the years 2010–2014, the CDC reported the annual estimated number and rate of HIV diagnoses in the U.S. as increased in some subgroups while decreased in others. Such variations in trends among groups were anticipated as a result of public education and testing outcomes in certain subgroups.

Some groups are affected more than others by HIV infection. Men who have sex with men (MSM) continued to bear the greatest burden of HIV infection; and, among races/ethnicities, while African Americans had been disproportionately affected, from 2010 through 2014, the rates for American Indians/Alaska Natives and Asians increased while the rates for blacks/African Americans, Native Hawaiians/other Pacific Islanders, and persons of multiple races decreased. The rates for Hispanics/Latinos and whites remained stable. In 2014, the rates were 49.4 for blacks/African Americans, 18.4 for Hispanics/Latinos, 15.4 for persons of multiple races, 10.6 for Native Hawaiians/other Pacific Islanders, 9.5 for American Indians/Alaska Natives, 6.2 for Asians, and 6.1 for whites.32

HIV Diagnoses

In 2011, an estimated 49,273 people were diagnosed with HIV infection in the United States. In that same year, an estimated 32,052 people were diagnosed with AIDS. Since the epidemic began, an estimated 1,155,792 people in the United States have been diagnosed with AIDS.4 At the end of 2013, an estimated 516,401 persons in the United States were living with infection ever classified as stage 3 (AIDS).32


Deaths

An estimated 15,529 people with an AIDS diagnosis died in 2010, and nearly 636,000 people in the United States with an AIDS diagnosis have died since the epidemic began.3 The deaths of persons with an AIDS diagnosis can be due to any cause — that is, the death may or may not be related to AIDS.



Risk Group

Homosexual, bisexual, and other men who have sex with men (MSM) of all races and ethnicities remain the population most profoundly affected by HIV.



  • In 2010, the estimated number of new HIV infections in MSM cohorts was 29,800, a significant 12% increase from the 26,700 new infections with MSM in 2008.

  • Although MSM represent about 4% of the male population in the United States, in 2010, MSM accounted for 78% of new HIV infections among males and 63% of all new infections.2 MSM accounted for 52% of all people living with HIV infection in 2009, the most recent year these data are available.

  • In 2010, white MSM continued to account for the largest number of new HIV infections (11,200), by transmission category, followed closely by black MSM (10,600).
  • The estimated number of new HIV infections was greatest with MSM in the youngest age group. In 2010, the greatest number of new HIV infections (4,800) with MSM occurred in young black/African American MSM aged 13–24. Young black MSM accounted for 45% of new HIV infections among black MSM and 55% of new HIV infections among young MSM overall.


  • Since the epidemic began, almost 300,000 MSM with an AIDS diagnosis have died, including an estimated 6,863 in 2009.

Heterosexuals and injection drug users also continued to be affected by HIV.

  • Heterosexuals accounted for 25% of estimated new HIV infections in 2010 and 27% of people living with HIV infection in 2009.

  • Since the epidemic began, more than 85,000 persons with an AIDS diagnosis, infected through heterosexual sex, have died, including an estimated 4,003 in 2010.

  • New HIV infections among women are primarily attributed to heterosexual contact (84% in 2010) or injection drug use (16% in 2010). Women accounted for 20% of estimated new HIV infections in 2010 and 24% of those living with HIV infection in 2009. The 9,500 new infections among women in 2010 reflect a significant 21% decrease from the 12,000 new infections that occurred among this group in 2008.

  • Injection drug users represented 8% of new HIV infections in 2010 and 16% of those living with HIV in 2009.

  • Since the epidemic began, more than 182,000 injection drug users with an AIDS diagnosis have died, including an estimated 4,218 in 2010.

The CDC 2014 surveillance report indicated that between the years 2010 - 2013, the rates of deaths for male and female adults and adolescents diagnosed with HIV infection decreased. The number of deaths among males with diagnosed HIV infection attributed to perinatal transmission increased. The number of deaths among males with infection attributed to injection drug use, male-to-male sexual contact and injection drug use, or heterosexual contact decreased. The number of deaths among males with diagnosed HIV infection attributed to male-to-male sexual contact remained stable. The number of deaths among females with infection attributed to injection drug use or heterosexual contact decreased. The number of deaths among female adults and adolescents with infection attributed to perinatal transmission remained stable.32


Race/Ethnicity

Blacks/African Americans were reported to experience the most severe burden of HIV, compared with other races and ethnicities.



  • Blacks represent approximately 12% of the U.S., population, but accounted for an estimated 44% of new HIV infections in 2010. They also accounted for 44% of people living with HIV infection in 2009.

  • Since the epidemic began, more than 260,800 blacks with an AIDS diagnosis have died, including 7,678 in 2010.

  • Unless the course of the epidemic changes, at some point in their lifetime, an estimated 1 in 16 black men and 1 in 32 black women will be diagnosed with HIV infection.

HIV had also disproportionately affects Hispanics/Latinos. Data extracted from literature showed:

  • Hispanics/Latinos represented 16% of the population but accounted for 21% of new HIV infections in 2010.2 Hispanics/Latinos accounted for 19% of people living with HIV infection in 2009.

  • Disparities persist in the estimated rate of new HIV infections in Hispanics/Latinos. In 2010, the rate of new HIV infections for Latino males was 2.9 times that for white males, and the rate of new infections for Latinas was 4.2 times that for white females.

  • Since the epidemic began, more than an estimated 96,200 Hispanics/Latinos with an AIDS diagnosis have died, including 2,370 in 2010.27

As mentioned previously, those diagnosed with AIDS in the 2014 CDC surveillance report indicated that from 2010 through 2014, rates for all race/ethnicity groups decreased. In 2014, the rates were 25.4 for blacks/African Americans, 12.6 for persons of multiple races, 7.7 for Hispanics/Latinos, 4.0 for American Indians/ Alaska Natives, 3.5 for Native Hawaiians/other Pacific Islanders, 2.7 for whites, and 2.1 for Asians.32



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