The following is a guest post by Jim Thomas, PhD
In 1978, the world celebrated the end of smallpox. Through a coordinated multinational effort, a global vaccination program had reached the furthest corners of the earth and eliminated the ability of the virus to spread. The success was intoxicating. Lists of the next diseases to eradicate were generated. The days of infectious diseases as major killers seemed to be fading into history. The new killers would be non-communicable. My own department of epidemiology at the University of North Carolina did not offer a concentration in infectious diseases. Instead, it concentrated on cardiovascular disease and cancers.
The overconfidence in managing infectious diseases was challenged just three years later, in 1981, when Acquired Immunodeficiency Syndrome — AIDS — was first described in the literature. This new infection seemed unlike any other. The modes of transmission concentrated the infections in populations that were socially vulnerable. If identified as infected, they were at risk of losing their jobs, relationships, health insurance, and more. Moreover, the virus causing the infection worked unlike any other, foiling attempts to find a cure or a vaccine. To reduce transmission, public health systems needed to address the infection from multiple angles: clinical, psychological, behavioral, social, cultural, legal, and political. This multifaceted approach included the recognition that structural factors in society push and pull people, often superseding individual choices, into contexts where the risk of infection is heightened. By this time, my department of epidemiology had established a strong program in infectious diseases, as well as a program in social epidemiology.
In recent years, pharmacologists found a way to suppress replication of the virus in infected people. And with small viral loads there came decreased transmission to others. Treatment thus also served as prevention. The idea of prevention with a pill quickly gained momentum. HIV prevention became dominated by pill-related goals, such as adherence to life-long medication regimes, and medication supply chains. This approach is evident in the UNAIDS 90-90-90 goal: by the year 2020, 90 percent of people infected with HIV will know they are infected; 90 percent of those people will initiate treatment with antiretroviral drugs; and 90 percent of them would adhere to medication well enough to experience viral suppression. The U.S. President’s Emergency Plan for AIDS Relief has adopted this same goal.
Interventions to address structural issues – those factors that facilitate transmission but cannot be addressed with a pill – have been overshadowed by the global push for treatment as prevention. This, even though some structural factors affect the availability of pills, such as information systems to monitor progress and direct resources as needed. Other structural factors enable uninfected people to remain that way, such as financial incentives to keep children in school. The 2013 evaluation of the PEPFAR program by the Institute of Medicine recommended increased attention to structural factors. Key evidence of attention is the evaluation of which structural interventions work.
Evaluations of Structural Interventions for HIV Prevention: A Review of Approaches and Methods — a recent publication in AIDS & Behavior by MEASURE Evaluation — reveals that few structural interventions for HIV have been conducted since the IOM report. But to facilitate more interventions, the publication also catalogs the methods used to evaluate the interventions, and additional methods that are appropriate for structural interventions.
Choosing means to address the HIV pandemic is not an either/or choice, it is both/and. To pursue structural interventions is not to back off on clinical interventions. But by the same token, pursuing clinical interventions should not mean backing off from addressing underlying and pernicious structural factors. Unlike smallpox, this complex epidemic requires a multifaceted approach.
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Jim Thomas is an associate professor of epidemiology in the Gillings School of Global Public Health, and director of the MEASURE Evaluation project in the Carolina Population Center at the University of North Carolina in Chapel Hill. MEASURE Evaluation is USAID’s flagship project for health information system strengthening in low- and middle-income countries.