The White House released the first National HIV/AIDS Strategy in July 2010 to provide "a concise plan that will identify a set of priorities and strategic action steps tied to measurable outcomes." Accompanying the Strategy is a Federal Implementation Plan that outlines the steps to be taken by Federal agencies.
Both the Strategy and the Plan recognize that new research activities will be needed to advance HIV prevention, treatment, and care. For example, "the Strategy cannot succeed without continued and sustained progress in biomedical and behavioral research ... current approaches to preventing HIV must be coupled with research on new and innovative prevention methods that can have a long-term impact." But neither document provides an overview of the main research challenges.
Existing evidence suggests that a voluntary "test and treat" approach could dramatically reduce new HIV cases within a decade. Some think it could even halt the pandemic. But before this approach can begin, it will be necessary to carry out research to study its feasibility, effectiveness, benefits to individuals vs. benefits to society, and cost-effectiveness.
The CDC estimates that over 200,000 people in the U.S. have HIV but are unaware of it. The percentage of those who don't know is higher in certain groups, such as young men of color who have sex with men (MSM). CDC guidelines from 2006 call for screening all patients for HIV, unless the rate of HIV infection in their risk group is extremely low. People in high-risk groups, such as MSM, injection drug users, sex workers, partners of people with HIV, and heterosexuals with more than one partner, should be screened at least once a year, as should people being treated for TB or sexually transmitted infections.
Knowing your HIV status provides significant individual and social benefits, and also helps to advance the goals of the Strategy. Early detection allows people to begin treatment at the best time. People who know they have HIV are much less likely to have unprotected sex. And those who are on treatment are also less infectious. Treatment also has an impact on reducing "community viral load" (the average viral load of people living in a certain area).
Social marketing campaigns in Washington, DC, and the Bronx are highlighting the importance of getting tested. In Washington, the number of publicly funded HIV tests increased from 19,766 in 2004 to 72,866 in 2008, and there was a 17% increase in the number of HIV diagnoses reported from 2004 to 2007. Between 2004 and 2008, there was also a significant increase in the length of time people took to progress to AIDS and a significant improvement in the time between diagnosis and entry into care.
But reaching much larger numbers of people will require a greater "routinization" of testing. This means the HIV test must be automatically offered in a variety of medical settings -- doctors' offices, clinics, emergency rooms, etc. Early evidence suggests that more extensive routine screening programs are likely to be cost effective only when focused on groups with a higher risk of HIV. For example, one large study of routine testing in six health centers in the South offered HIV tests to 16,291 adults. Over 11,300 agreed to be tested, but only 17 tested positive. That may not be the best use of precious HIV dollars.
Given current budget limitations, the Strategy must be mindful of costs. Research is needed to determine when and where routine testing should be done. One early finding in San Francisco found that a high percentage of people who received an HIV diagnosis late in their disease did so in emergency rooms. This reveals a lost opportunity for early diagnosis. Important research topics include how to develop protocols for routine HIV testing in different settings, and studying how the offer of HIV testing is affected by what condition brought the patient there, language barriers, or even time of day.
To achieve the Strategy's goals, research is needed on how to identify more people earlier in their infection. Community mobilization and outreach strategies could be promising ways to increase the frequency of testing. These could include text messaging and incentives (like bus fares or snacks) for regular screening, and making testing more of a norm within communities. Although a great deal is already known about community mobilization, more research is needed on community preparedness, the involvement of community leaders, linkage to other community goals, and outreach strategies like testing at events.
Promising approaches to diagnose HIV-positive people earlier include improved testing technologies, awareness campaigns for providers and for people at risk, and counseling protocols for use when people test positive. One study at the University of California, San Francisco followed a high-risk, mostly homeless group of drug users and found that more frequent testing (every three or six months) was more acceptable than testing based on symptoms. It also found that it's best to bundle HIV testing into other services, make the process quick and convenient, and offer incentives. This could help to advance the Strategy's second goal of increasing access to care and improving the health outcomes of people with HIV.
HIV infection is a lifelong disease, and testing is only the first step of a long relationship between patients and providers. It requires regular check-ups and management of treatment regimens. "Treatment engagement" is defined as the patient seeing the provider at least once in a six-month period. Using this definition, one study found that those who were highly engaged had an average viral load below 17,000, while those not engaged had an average over 28,000.
Previous guidelines recommended HIV treatment for people with CD4 counts below 350, but that number has now been revised upward to 500. Some providers and public health experts recommend treatment for all people with HIV, regardless of CD4 count, for improved health outcomes and public health. Mathematical modeling suggests that more widespread treatment could result in many fewer infections. This would greatly assist in advancing the goals of the Strategy.
But linkage to care and retention in care are distinct processes. Engagement in care is vital for HIV treatment success, especially for members of groups with a high rate of HIV infection. Additional services, such as mental health and substance abuse care, play a crucial role in engagement and retention. Research has shown that missed visits in the first year of care are associated with increased mortality, but there have been no controlled trials or even a consistent definition of retention. Is it measured as one visit in three months or in six months? Data are also not linked to the content of the visit, making it difficult to assess the reasons people don't return for follow-up.
There are few studies on linkage and retention in care. One study sponsored by the CDC, however, found that five case management sessions resulted in increased linkage to care. At six months, 78% of those receiving the intervention kept an HIV provider appointment, compared with 60% of those who did not receive the intervention. At 12 months, 64% who were in the intervention arm kept an HIV provider appointment versus 49% of those who were not. Additional research in this area is needed.
Another major obstacle to retention in care is medication adherence. Research shows that adherence approaches should include practical tools like pill boxes, alarms, calendars, etc. We should also address complex barriers like stigma, access to care, cultural beliefs, economic problems, and depression. Further research is needed in all of these areas, as well as on the impact of various approaches, such as cognitive, behavioral, and social support; contingency management; home visits, and directly observed therapy.
There is also a need for mental health and substance abuse care for people with HIV. Short computer-based screening in waiting rooms could be combined with risk assessment, and more innovative use of electronic medical records could also offer benefits. This is yet another area where more research is needed.
As President Obama noted in the opening statement of the National HIV/AIDS Strategy, "researchers have produced a wealth of information about the disease, including a number of critical tools and interventions to diagnose, prevent, and treat HIV." With solid evidence based on rigorous research, the National HIV/AIDS Strategy finally provides an opportunity to get ahead of the epidemic. But that will only be possible with more evidence and further research, to build on prior successes.
Stephen Morin is director of the Center for AIDS Prevention Studies at UCSF. Raymond Smith and Robert Remien are research scientists at the HIV Center for Clinical and Behavioral Studies, NYS Psychiatric Institute, and Columbia University.