HIV/AIDS epidemic at 30 years: Promised land or wasteland?
Treatment as prevention possible answer
Thirty years after the world first became aware of a strange syndrome that caused young men to acquire rare diseases like Pneumocystis carinii pneumonia (PCP) and Kaposi's Sarcoma, nations across the globe continue to battle against the HIV/AIDS epidemic.
Scientists have discovered after years of research that a combination of potent antiretroviral therapy (ART) drugs can help HIV-infected patients lead relatively healthy lives. Most recently, they've learned that these same drugs are a potent public health weapon against transmission of this pernicious virus. Studies show that the drugs lower the virus to undetectable levels with very low risk of transmission. Also there are proven behavioral methods for reducing risk, including condom use, clean needle exchange programs, ARTs to prevent mother-to-child transmission, circumcision, etc. Other prevention methods seem always on the verge of game-changing breakthroughs, including antimicrobials for women and some sort of vaccine.
So with this much knowledge and progress, the question remains: why is HIV still an epidemic in the United States?
Investigators who have studied HIV disparities, timing of HIV diagnosis, the U.S. national prevention strategy, and the AIDS Drug Assistance Program (ADAP) each present a piece to a puzzle that suggests the technical and scientific solutions to the epidemic are within our reach, but the economic and political will are not. As AVAC — Global Advocacy for HIV Prevention — states on its website at www.avac.org, the HPTN 052 trial using ART as a prevention strategy shows conclusively that treatment is prevention.1
All that is needed is the political and economic will to make that happen.
"It's very difficult to implement a national strategy," says Baligh Yehia, MD, a post-doctoral fellow in the division of infectious diseases at the University of Pennsylvania in Philadelphia, PA. Yehia also is a student at the Woodrow Wilson School of Public Health and International Affairs at Princeton University in Princeton, NJ.
Yehia has studied the U.S. HIV prevention strategy from over the past 30 years and evaluated the latest goals proposed by the Centers for Disease Control and Prevention (CDC) of Atlanta, GA.
"The biggest thing is unfortunately that in our economy right now there are no new funds devoted to this HIV prevention plan, and that's a major hurdle to accomplishing this strategy," Yehia says. "Folks are shuffling around different pots of money, and that's important and making us more focused, but there is no new money being contributed other than what was put in the Affordable Care Act."
The CDC's most recent five-year goals included the aim of reducing new HIV infections by 25%.
"It is hard to measure the impact of the strategy, given the delay in CDC estimates, which is a call for a better, more real-time measuring systems," Yehia says.
"The latest CDC estimates suggest 48,000 new infections a year, including huge increases among young men who have sex with men (MSM)," he says. "Young MSM of color is the populace most at risk of contracting HIV in this current time."
What has not changed is chronic underfunding. The Obama administration's National HIV/AIDS Strategy for the United States is the most comprehensive federal response to the domestic epidemic so far. The new prevention strategy's goals are to reduce the number of new HIV infections, improve access to care and health outcomes, and reduce HIV-related health disparities. Yet, it is critically underfunded with only $30 million dedicated funds to expand the strategy's prevention efforts.2
Yehia points out that electronic models suggest the total cost of implementing the Obama prevention plan would be about $15 billion, with more than two-thirds of the cost going toward treatment and medical care services.2
The U.S. national HIV/AIDS strategy and movement is heading in the direction of a population-based approach, says Julia Dombrowski, MD, MPH, acting instructor in the department of medicine at the University of Washington and deputy director for clinical services in the HIV/STD program at the Public Health Seattle King County in Seattle, WA.
"The goal was to ensure people who are infected get diagnosed soon after getting the disease and are linked to medical care," Dombrowski says.
"Not only the individual benefits from doing all those things, but also the public health benefits since we know ART can reduce sexual transmission," she adds. "Treatment as prevention is an appealing concept, and we need to do more interventions on how to operationalize it."
Treatment and prevention are on a continuum in this epidemic, notes David Hanna, MS, a doctoral student in epidemiology at Johns Hopkins Bloomberg School of Public Health in Baltimore, MD.
"It's all related — if a person with HIV does not get treatment, we've known for years that his chances of disease progression and eventually death are significantly higher," Hanna says. "But recent studies have found improvements in shorter-term prevention-related outcomes, as well: someone getting on therapy may be able to reduce her viral load to undetectable levels and in turn the likelihood she'll transmit her infection to somebody else."
Hanna's research has found striking differences in HIV case-fatality rates between regions of the country. For instance, Southeastern states have among the nation's highest HIV case-fatality rates in the nation. While there are eight states that have HIV case-fatality rates of 25.3 (or higher) per 1,000 HIV-infected person years, all but two of these states are in the Southeast. The exceptions are Wyoming and Oklahoma.3
On the other side of the equation, two Northeastern states with the highest conventional HIV death rates, which are calculated by HIV deaths per 100,000 general population person years, are New York and New Jersey, which have large HIV populations and lower HIV case-fatality rates. This difference between the two measures is especially striking in the case of New York which has the third highest conventional HIV death rate, but only the 30th (out of 37 states) HIV case-fatality rate. Wyoming is its counterpart with the second lowest conventional HIV death rate, but the 9th highest HIV case-fatality rate. These differences suggest there are disparities in how efficiently various state and regional populations access HIV care and treatment.3
"The data are consistent with other studies showing greater disparities in the South with respect to HIV, but our study uniquely focuses on differences in mortality that may have arisen from the availability, use, and quality of HIV care in these states," Hanna notes.
States manage their ADAPs differently, and the programs' formularies, waiting lists, and funding can vary widely, he adds.
"Budgets play a role in states' decisions on how to run the program," Hanna says. "We think it's worth looking into differences in how programs like ADAP are run, and we're hoping to understand these scenarios better in our ongoing work."
Hanna's study looked at the HIV case-fatality rates between 2001 and 2007. But a look at a recent ADAP waiting list report might predict that disparities have only increased in the four years since then. In the September, 2011, ADAP table, there are 11 states with waiting lists — a phenomenon that had disappeared briefly before the Great Recession. Of those 11 states, six are in the Southeast. And those six states account for 7,774 out of the nation's total of 9,066 HIV-infected people on ADAP waiting lists.
Since ADAPs are the source of antiretroviral drugs for a large proportion of uninsured HIV-infected people, their formularies and waiting lists can play pivotal roles in the epidemic. As one recent study found, ADAPs are an important medication resource for HIV-positive women.4
The ADAP study used data from 2008, looking at state ADAP formularies in New York, California, and Illinois — all of which are states with large ADAPs, says Nancy Hessol, MSPH, adjunct professor, University of California — San Francisco.
"We collected extensive amounts of data on women study participants every six months, used their blood pressure data and asked about HIV antiretroviral medications," Hessol says.
Investigators compared access to highly active antiretroviral therapy (HAART) among women who had access to ADAP with those who did not have access to ADAP.
"The most important thing we found was that women without ADAP were more than two times more likely to not be on HAART," Hessol says. "The women on ADAP were more likely to be on HAART."
In all cases, the women were clinically eligible for HAART, she adds.
"A lot of things have happened since 2008," Hessol says.
The small increases in federal appropriations for HIV testing and prevention, coupled with high drug costs and new treatment guidelines calling for earlier initiation of HAART, all could lead to greater demand for antiretroviral therapy as more people enter treatment and remain in treatment, she explains.
"It's unfortunate because there is a growing number of individuals on ADAP waiting lists," Hessol says. "When you disenroll somebody and kick them out of ADAP, you increase the chance that person will develop virologic resistance to the virus and medicine."
- El-Sadr WM, Coburn BJ, Blower SM. Modeling the impact on the HIV epidemic of treating discordant couples with antiretrovirals to prevent transmission. AIDS. 2011;[Epub ahead of print.]
- Yehia B, Frank I. Battling AIDS in America: an evaluation of the national HIV/AIDS strategy. AJPH. 2011;July 21:[Epub ahead of print.]
- Hanna DB, Selik RM, Tang T, et al. Disparities among states in HIV-related mortality in persons with HIV infection, 37 U.S. states, 2001-2007. AIDS. 2011;[Epub ahead of print.]
- Yi T, Cocohoba J, Cohen M, et al. The impact of the AIDS Drug Assistance Program (ADAP) on use of highly active antiretroviral and antihypertensive therapy among HIV-infected women. JAIDS. 2011;56(3):253-262.