On December 1, World AIDS Day, should we wish the human immunodeficiency virus (HIV) a happy birthday?

We don’t know the exact day the virus infected its first human host, but scientists have shown that the virus has been active in humans for about a century. A biography of the disease would show a dynamic, lethal virus that worked for decades in relative obscurity before bursting on to a worldwide stage in the early 1980s and rewriting the script of human progress against disease.

A sign from Zambia in 2005.

The résumé of HIV is astounding. Its dominant form, HIV-1, has killed 35 million people since 1981 and it has infected roughly the same number again. Nearly 37 million people live with the disease today.

By disabling human immune systems, HIV has also allowed tuberculosis to come thundering back as a global health threat and has reduced life expectancies in many hard-hit countries.

Estimated HIV/AIDS prevalence in 2011.

More positively, HIV has forced societies to shift the debate on rights and inclusion for sexual and gender minorities. Gay populations have become more visible and politically active, winning civil rights and acceptance in the wake of the disease’s devastation.

HIV has sped up the processes for drug approval in the United States and reframed the ethical framework for patient participation in research studies. The virus has also spurred scientists to create a large number of drugs in a very short time that are effective in halting the advance of the disease. Furthermore, conflicts over HIV undercut global intellectual property laws that protected drug companies and made lifesaving drugs inaccessible.

The logo for the Joint United Nations Programme on HIV/AIDS.

The responses to the disease have also challenged global public health governance and rewired the global health apparatus. The World Health Organization began the fight against the disease in the 1980s but their efforts were ineffective. The United Nations took over in 1996, through the Joint UN Programme on HIV/AIDS (UNAIDS).

The 2015 logo for the President’s Emergency Plan for AIDS Relief in the Central Asia Region.

Concerns about funding and management of UNAIDS, however, led bilateral donors and private foundations to establish a public-private financing institution, the Global Fund to Fight AIDS, Tuberculosis, and Malaria, in 2002. The next year, the United States began what would grow to a $70 billion investment in controlling HIV over 15 years through the President’s Emergency Plan for AIDS Relief (PEPFAR) and the Global Fund.

All of this happened as a result of a seemingly unlikely occurrence: a human living about one hundred years ago in Equatorial Africa became infected by a closely related virus in the blood of a chimpanzee.

HIV is derived from simian immunodeficiency virus, and we hypothesize that it crossed over to humans through blood to blood contact, probably during butchering or hunting chimpanzees. When the simian virus entered the human’s blood stream, it gradually took over cells in the immune system, hijacking CD4 cells to make new copies of the virus before killing the cells.

From left to right, the African green monkey (the source of simian immunodeficiency virus), the sooty mangabey monkey (source of HIV-2), and the chimpanzee (source of HIV-1).

The insidious thing about the virus, however, is that it does its work slowly. Without treatment, HIV has a latent phase that can last between six and ten years. During that time, people harboring the virus do not know they have it, but they can spread the virus to others through sexual contact, blood-to-blood contamination, and mother to child transmission.

The story of HIV is a story of globalization. The expanding connections of the twentieth century spread the disease, yet the limitations and inequalities of global public health allowed the disease to ravage populations even after scientists discovered effective drug treatments.

A Virus Appears

In the nearly four decades since 1981, when a cluster of unusual pneumonia cases in Los Angeles introduced the world to AIDS (Acquired Immune Deficiency Syndrome), scientists have dug into its past to determine the history of the disease.

The archive of this history turned out to be two previously forgotten samples from blood plasma and a lymph node stored in a laboratory in the Democratic Republic of the Congo. By testing these two samples from 1959 and 1960, the period just before and just after the Congo became an independent nation, scientists found remnants of HIV.

A stamp commemorating the Democratic Republic of the Congo’s independence (left). A map of the Congo (right).

Because HIV has a defined mutation rate, researchers were able to compare these two samples and more recent strains of HIV to construct a family tree all the way back to a common ancestor virus. This pointed the scientists to the period when the simian virus became a human virus. But where did this happen?

They found the answer in monkey poop. A team of scientists collected the feces of chimpanzees across a wide belt of Equatorial Africa. By locating and isolating the strains of the simian virus in these samples, they pinpointed the chimpanzees with the strain of simian virus closest to the human virus on the banks of the Sangha River, a tributary to the Congo, that runs through southeastern Cameroon.

Colonial Africa: The Crucible of HIV

The globalization of European imperialism helped incubate and spread HIV within Africa.

An 1899 map of Africa highlighting its railways, navigable waters, and distances from the coast. 

This virus began its career in humans at a time when the forests and riverine landscapes of Equatorial Africa became increasingly connected to the global economy. While the people who lived in these forests had traded and been connected to wider regional networks for a very long time, the scope and scale of these interactions changed at the end of the nineteenth and beginning of the twentieth centuries.

European countries claimed sovereignty over much of Africa in the wake of the 1884 Berlin Conference. In Equatorial Africa, European countries broke their territories into concessions and then private companies bought the rights to control these areas and their resources.

An 1892 caricature of Cecil Rhodes, a British businessman who served as Prime Minister of the Cape Colony, standing from “Cape to Cairo” (left). A 1939 map of Africa with flags representing the colonial claims (center). A 1905 caricature of Belgian King Leopold II with his earnings from the Congo Free State and exploited workers in the background (right).

Concessionary companies worked in the Sangha river basin, and the brutal exploitation of people to extract ivory and rubber in the broader region inspired Joseph Conrad’s novel Heart of Darkness. The horrors of this exploitation led to a widespread campaign against the Belgian King Leopold II’s murderous reign in the Congo.

European colonialism built an infrastructure that helped link previously unconnected regions. Steamboats plied the rivers, speeding the transport of goods and people. New towns on the river grew into trading centers and colonial outposts.

Two towns on opposite sides of the Congo River, Leopoldville (now Kinshasa) and Brazzaville, attracted Africans from across the equatorial belt.

A satellite image of Brazzaville, Kinshasa, and the Malebo Pool (formerly Stanley Pool) of the Congo River (left). Papa Wendo Kolosoy’s 2004 album “On the Rumba River” (right).

In the 1940s and 1950s, the creative energies of these towns produced the lively sounds of rumba, music inspired in part by Latin American sound and driven by the distinctive Congolese guitar playing. But the same venues and impulses that attracted the youth to hear people like Papa Wendo Kolosoy croon “Marie Louise” created conditions for the spread of the virus through heterosexual intercourse.

While it is impossible to know how many people were infected with HIV in this period, rates of other sexually transmitted diseases like Hepatitis B suggest that HIV could have spread widely. And it was in 1959, the last year of Belgian rule in the Congo, that a doctor in Leopoldville took a fateful tissue sample from a patient.

Decades later this obscure sample from colonial Africa would help unlock the origins of HIV.

HIV-1 (in green) under a scanning electron micrograph (left). A phylogenetic tree of the HIV and simian virus (right).

From Africa to the World

If colonial Africa incubated and magnified the reach of HIV-1, however, it was the end of European colonization and the tensions of the Cold War that created the conditions for the global spread of the disease.

The 1960s have been hailed as the African Decade because so many African countries emerged from colonialism. But these emerging nations also became battlefields in the Cold War struggles between the United States and the Soviet Union. The Congo provides the most striking example of this in the 1960s.

Patrice Lumumba (left center) immediately after being sworn in as the first Prime Minister of the newly independent Democratic Republic of the Congo in 1960 (left). Portuguese soldiers in Angola during the War of Liberation between Portugal and Angola from 1961 to 1974 (right).

The Belgians rushed the process of Congolese independence in 1960, but in the days following the formal handover of power to Prime Minister Patrice Lumumba, the country’s most resource-rich province, Katanga, seceded. Katanga’s mines produced vast amounts of copper as well as the uranium that produced the fuel for the American bomb that decimated Hiroshima.

The secession sparked a five-year conflict during which Lumumba was assassinated and overthrown, the UN Secretary General Dag Hammarskjöld’s airplane was shot down, and Belgian and UN troops occupied parts of the country. Joseph Mobutu, an army officer, emerged as the head of state in the Congo and remained a staunch Cold War ally of the United States.

A 1961 map of the factions in the Congo (left). Swedish UN soldier in the Congo in the 1960s (right).

A side effect of Congo’s rushed independence and the resultant crisis was a dearth of people with professional training and experience. In response, the United Nations Education, Science, and Cultural Organization (UNESCO) and the Congolese government recruited teachers and doctors to come work in the Congo. After Belgians, Haitians made up the largest number of these expatriate professionals.

A Cuban tank in Angola in 1976.

There were an estimated 4,500 Haitians in the Congo in the 1960s, and more came in the 1970s. These Haitian professionals sought respite from their own Cold War dictator. While in Congo, however, some contracted HIV and subsequently returned home with the deadly, unknown virus. The earliest cases of HIV in the United States are connected to Haiti, and the Haitian-Congo link seems to have helped the disease cross the Atlantic.

Angola’s liberation struggle and civil war in the 1970s and 1980s also connected the Cold War and the global spread of HIV.

Fidel Castro committed Cuba’s Communist government to support the People’s Movement for the Liberation of Angola (MPLA) in their struggles to control Angola, both up to Angolan independence in 1975 and during the civil war that followed. Tens of thousands of Cuban soldiers, aid workers, and doctors were sent to Angola between the 1960s and the early 1990s.

Cuban and Angolan forces eventually defeated the South African Defense Force in Angola in 1988, which set into motion the independence of Namibia, the freeing of Nelson Mandela, and the end of apartheid.

A map showing Cold War alliances in 1980.

For many Cubans who served, however, the momentous outcome of their African service was the virus they contracted.

We now understand this pre-history of AIDS. Looking back, doctors can see that a small number of unexplained medical cases in the west from the 1960s and 1970s were early cases of AIDS. Scientists’ more recent efforts to identify the genetic subtypes of HIV and put them into family trees reveals the disease’s evolution and movement.

Interactive graph of the number of people infected with HIV by region (Institute for Health Metrics and Evaluation and Our World in Data).

By the 1970s, a powerful wave driven by decolonization and Cold War rivalries was cresting. In the early 1980s, this wave crashed around the globe.

AIDS Emerges among Gay Men in the U.S.

A curious cluster of unusual pneumonia cases in Los Angeles in June 1981 resulted in the first public health report of a pattern of infections among gay men.

A cover page of the Centers for Disease Control’s Morbidity and Mortality Weekly Report in 1981, soon after its initial report set off alarm bells.

The Centers for Disease Control’s Morbidity and Mortality Weekly Report of June 5 set off alarm bells for a small number of physicians who had seen similar strange cases of failing immune systems that left the body susceptible to infections that healthy people repel every day. They saw young men who had diseases like pneumocystis carinii pneumonia and Kaposi’s sarcoma, infections that they would never have seen in otherwise healthy people.

The medical mystery was a lived misery. Healthy young people suffered terribly from rashes, diarrhea, and infections. Thrush in their mouths and throats made it hard to swallow. Some lost their vision and others developed dementia. With the progression of the disease, the infected withered and hollowed, becoming unrecognizable. The stigma of being gay in the United States discouraged some from seeking treatment when they became ill, and those who did faced discrimination in many forms, including refusal of care from hospitals.

The disease was initially called a “gay cancer” and then Gay-Related Immune Deficiency (GRID) in the United States, but it dawned on physicians in Africa that their heterosexual patients had the same disease. The Centers for Disease Control gave the new disease a more neutral name, Acquired Immune Deficiency Syndrome (AIDS), in September 1982.

A newspaper clipping from 1981 (left). Ryan White, a boy with hemophilia, became a poster child for HIV/AIDS in the U.S. after his school refused to readmit him after his diagnosis of AIDS in 1984 (right).

Naming the disease was easier than characterizing it, and the early diagnosis was based on having a number of AIDS-defining illnesses. With no known cause and no known cure, these were desperate times.

Hemophiliacs contracted AIDS from donated blood, and tainted blood supplies spread fear in society. People believed they could contract AIDS from a sneeze or a toilet seat, and the panic further marginalized those who had the disease.

Congresswoman Nancy Pelosi at the Second National March on Washington for Lesbian and Gay Rights in 1987 (left). Despite being close friends with Rock Hudson, President Ronald Reagan and Nancy Reagan made no public statements regarding the actor’s death from AIDS in 1985 (right).

Stigma and fear shaped official responses to AIDS in western countries where gay men were most affected. Conservative governments under Ronald Reagan and Margaret Thatcher avoided the subject of AIDS for as long as possible and provided grossly inadequate funding for research and outreach. The virus that caused the disease was not definitively identified until 1984, and the first test for it was not available until 1985.

But there was still no cure. AIDS was a death sentence.