Online this week in The Independent (Rwanda Edition): How public health efforts likely contributed to the early spread of HIV.
The Tragic Amplifier
Published online December 8, 2011.
This year marks the 90th anniversary, approximately, of the introduction of human immunodeficiency virus (HIV) into the human population. It also marks thirty years since HIV was first scientifically recognized in 1981. Since the 1920s, this virus has spread across the globe and become the HIV/AIDS pandemic we are all too familiar with today. Most people consider the 1980s to be the beginning of the HIV/AIDS pandemic, but the virus had been prevalent in populations living in parts of central Africa for decades before it became a global nightmare.
New evidence from epidemiologist and international health expert Jacques Pepin suggests that human efforts to improve public health in central Africa were critical in facilitating the early spread of HIV, which has since claimed nearly 30 million lives. In the past two decades, massive coordination, mobilization, innovation, and investment have managed to slow the epidemic and save millions. As we mark World AIDS Day on December 1, 2011, HIV/AIDS is a reminder to us all of the tremendous power of human folly, but also of human triumph.
The Origins of AIDS, by Pepin, is a remarkable new book that pieces together the emergence of HIV in the human population, and its subsequent spread across the globe. HIV is the human version of simian immunodeficiency virus (SIV), which has been present in chimpanzee populations of central Africa for hundreds of years. Human contact with chimpanzees led to at least one transmission of SIV to HIV in a human in the early 1920s, most likely a hunter or a cook living in central Africa, where the majority of SIV-carrying chimpanzees live. This transmission alone was extremely unlikely to have triggered an HIV epidemic, and indeed chimpanzee-to-human transmission could have occurred on separate occasions prior to the 1920s, but would not have spread far. An infected hunter may have passed HIV to his family members, but in all likelihood, the virus would have stopped there. Why did HIV begin to spread beyond a few infected individuals in the early 1920s?
Pepin argues that heterosexual transmission, which is the predominant mode of transmission of HIV today, could not alone have led to an outbreak of HIV on a scale that would trigger a pandemic. Thus, there must have been some kind of “amplifier” that allowed for very rapid transmission of HIV to many people at a time. And what was the mostly likely initial culprit in the amplification of the virus? Colonial public health campaigns involving widespread use of unsterilized syringes and needles.
In the 1930s and 1940s, colonial administrations in French Cameroon, the Belgian Congo, and elsewhere began massive public health campaigns to treat various infectious diseases, including yaws, syphilis, malaria, leprosy, and sleeping sickness, using syringes and needles which were not sterilized regularly, if at all (oral tablet versions of treatments were not available for these diseases at the time). Although there are no blood samples from this time period still in existence (the oldest blood sample in which HIV has been detected dates back to 1959, taken from a man living in Leopoldville, Congo, now known as Kinshasa), it is well documented that other less lethal viruses, like Hepatitis C, were transmitted via syringes in Cameroon, Gabon, and the Belgian Congo, among other colonies. It is not difficult to imagine that HIV could have been passed quickly through a population via syringe as well.
One clinic to treat sexually transmitted diseases (STDs) in Leopoldville treated up to 1000 patients a day by the mid-1950s, with documented evidence that medical equipment was not sterilized between patients. To make matters worse, HIV was likely introduced into Leopoldville/Kinshasa at a time when there was a dramatic gender imbalance due to colonial policies. Urban areas like Leopoldville were often the equivalent of “work camps” in which wives and children were not welcome, which resulted in widespread prostitution, further facilitating the spread of HIV through heterosexual transmission.
HIV, which first spread through non-sterile syringes, often in clinics aimed at treating sexually transmitted diseases among men and sex workers in urban areas, kept at a steady prevalence through heterosexual transmission among the same population. In the colonial period, female sex workers, or “free women”, had only a few regular clients each year, but by the time of independence, female prostitutes would often see up to 1000 clients per year. This new type of prostitution greatly facilitated the transmission of HIV to populations beyond urban areas, and spread along major trades routes and cities in central and eastern Africa, including Kigali.
By 1984-85, Kigali, which at the time had a high ratio of males to females, and thriving prostitution, had the highest recorded HIV prevalence in the world, with 80 percent of prostitutes, 50 percent of STD patients, and 15-20 percent of blood donors, factory workers, and hospital employees testing positive for HIV. By 1987, HIV prevalence was at 17.8 percent in urban areas and jumped to 27 percent in urban areas by 1996.
From central Africa, HIV soon spread to Haiti, before being transmitted via multiple routes to the United States and beyond. Today, 34 million people are living with HIV/AIDS, and another 29 million have perished. That the spread of this virus was likely facilitated, and perhaps only possible, with the help of human technology and early public health campaigns should give us pause, and remind us of the terrifying potential for destruction due to human folly. As Pepin writes, “When humans manipulate nature in a way that they do not fully understand, there is always a possibility that something unpredictable will occur.”
Turning the tide on the spread of HIV/AIDS has taken decades, and millions have tragically lost their lives in the process. But the HIV/AIDS epidemic also demonstrates the amazing power of human innovation and cooperation that can take place on a global scale. Today, there are 6.6 million people receiving life-saving antiretroviral treatment, and both AIDS-related deaths and new HIV infections are declining in most parts of the world. The time, research, energy and money that have gone into tackling HIV has been phenomenal. If anything, we are now in danger of devoting too few resources to other health challenges that must also vie for the attention of the global health community and domestic health budgets.
HIV/AIDS is an extraordinarily painful reminder of the good intentions that can pave the road to hell, and of the unique capability of humans to create as well as destroy.