The Lancet, Early Online Publication, 20 March 2009
doi:10.1016/S0140-6736(09)60321-4 Cite or Link Using DOI
AIDS: lessons learnt and myths dispelled
Prof Peter Piot MD a b, Prof Michel Kazatchkine MD c , Mark Dybul MD e, Julian Lob-Levyt MB d
Nearly 30 years into the AIDS epidemic, we are able to assess our progress in tackling the disease with both increased knowledge and the benefit of hindsight. This Viewpoint examines what we—the international community—got right, what we got wrong, and why we need to urgently dispel several emerging myths about the epidemic and the global response to it.
When HIV was emerging in the early 1980s, we clearly underestimated the global effect that the disease would have, and that in only a few decades, tens of millions of people worldwide would become infected. The epidemic nowadays is the result of what 30 years ago was an unpredictable—but tremendously potent—combination of intimate personal behaviours (notably, unprotected sex and needle sharing) and socioeconomic factors (including poverty, gender inequity, social exclusion, and migration) that have affected nearly every country worldwide.
We also underestimated the extent to which stigma and discrimination—against people living with HIV and those most vulnerable to it—would remain formidable obstacles to tackling AIDS. Although the introduction of antiretroviral treatment in developed countries 12 years ago and its dissemination to developing countries in recent years has largely changed the perception that AIDS is a so-called death sentence, people living with HIV/AIDS in many countries continue to experience ostracism, violence, eviction, loss of employment, and restrictions on their ability to travel. Stigma and fear of discrimination still prevent many people from accessing crucial prevention and treatment services, including HIV testing. Roughly 60 countries worldwide continue to deny or restrict entry to people living with HIV/AIDS, showing how differently HIV infection is perceived and treated compared with other diseases.
Notwithstanding these challenges, we can also say that, after years of inadequate action, we underestimated the sense of urgency and solidarity that would eventually develop in the global AIDS movement, leading to an unusual convergence of political will, money, and science. Since the UN General Assembly Special Session on AIDS in 2001, the international community has substantially increased resources available for AIDS by creating the Global Fund to Fight AIDS, Tuberculosis and Malaria. The USA has launched the US President's Emergency Plan for AIDS Relief (PEPFAR). As a result, more than 3 million people have now gained access to antiretroviral treatment, which was unimaginable only 5 years ago. People living with and affected by HIV, non-governmental organisations, civil society groups, and the private sector are more engaged in the response than ever before. However, in an unstable global political and economic environment, we will all have to work even harder than previously to ensure that this momentum is expanded and sustained.1
Some aspects of HIV/AIDS were also overestimated in the early years of the epidemic—notably, the pace with which HIV would spread in regions other than sub-Saharan Africa. For example, in the early 1990s, many were concerned that, left unchecked, HIV in Asia would spread quickly outside concentrated epidemics of sex workers, men who have sex with men, and injecting drug users, and that the disease would take on the proportions of the devastating generalised epidemics occurring in southern Africa.
Fortunately, this scenario has not yet happened, other than in Papua New Guinea, which now has a serious AIDS epidemic. Nevertheless, the Asian epidemic is showing its own worrying trends. A growing proportion of people with HIV in the region are women—notably married women. In Vietnam, women now account for a third of people infected.2 At the same time, HIV prevalence in men who have sex with men is growing across Asia—eg, the proportion of men who have sex with men in Bangkok who are living with HIV increased from 17% to 28% between 2003 and 2005.3 Because the continent of Asia has a very large population—more than 2•5 million people are living with HIV/AIDS in India alone—it will continue to demand substantial resources and intensive efforts to improve HIV prevention strategies and provide treatment to people who need it.
Meanwhile, our ability to estimate the number of people living with HIV/AIDS has become increasingly advanced. Estimates from UNAIDS/WHO are based on all relevant data available, including surveys of pregnant women attending antenatal clinics, population-based surveys, sentinel surveillance in populations at increased risk of HIV infection, case reporting, and registration systems. Different combinations of these approaches, and the consensus reached by leading experts nationally and internationally, are producing both improved data from country surveillance and steady advances in modelling methods. The overall result is increasingly accurate estimates.
Despite the remarkable innovations and successes of antiretroviral treatment, we have also overestimated our capacity to devise technological solutions to prevent HIV. Notwithstanding the optimistic projections of the US Health and Human Services Secretary Margaret Heckler in 1984, that an AIDS vaccine would be ready for testing in about 2 years, we still seem many years away from either a vaccine or a microbicide to protect against HIV transmission, especially after a recent series of disappointing trial results.4, 5 Nevertheless, much has been learned about how HIV enters and acts within the body, and continued investments in new prevention technology remain a crucial part of the AIDS research agenda. Encouragingly, in the past 2 years, studies have shown that male circumcision reduces HIV infection in men by up to 60%,6 although it does not reduce transmission from men to women or between men.
One of the most common myths is that HIV prevention is not working. However, much evidence suggests that, in several countries, prevention programmes are effective. Between 2005 and 2007, coverage of services to prevent mother-to-child transmission of HIV increased from 14% to 33%.7 As a result, in 2007, we noted for the first time a substantial decrease in the number of children born with HIV.
Prevention is, of course, about not only technology, but also behaviour. In many countries on several continents, changes in sexual behaviour (such as waiting longer to become sexually active, having fewer partners, and increased condom use) have been followed by reductions in the number of new HIV infections, providing evidence that efforts to change behaviour can and do work.8
However, sustaining behaviour change in the long term remains a major challenge. For example, the number of new HIV diagnoses in men who have sex with men doubled in Germany between 2002 and 2006, and increased by more than three-quarters in Switzerland.2 These data could be attributable to complacency about AIDS and the sense that a treatable disease is somehow less threatening than are other diseases, and to a decrease in HIV prevention efforts in western Europe. Some developing countries that have previously had much success with HIV prevention, such as Uganda, have also had increases in rates of HIV transmission.2