October 22, 2012
African-American men who have sex with men (MSM) remain disproportionately impacted by the HIV/AIDS epidemic in the U.S., but the causes of and solutions to this disparity defy easy definition, according to an oral presentation at the inaugural IDWeek meeting in San Diego.
Of about 50,000 persons in the U.S. who were newly infected with HIV in 2009, the most recent year for which national surveillance numbers are available, 44% were African American, according to the Centers for Disease Control and Prevention (CDC). "Although black MSM account for less than 1% of the U.S. population, they comprise one in four of new infections every year," said Greg Millett, M.P.H., a behavioral scientist at the CDC in Atlanta.
Millett noted the alarming data on the HIV "treatment cascade" that has become one of the most widely discussed topics in U.S. HIV care today: Of approximately one million people living with HIV in the U.S., only 82% are diagnosed, only 33% have been prescribed antiretroviral therapy and only 25% are virologically suppressed.
But in every step of that treatment cascade, black MSM are worse off than the general population, Millett said. He cited data that he and his colleagues published earlier this year in Lancet showing that black MSM are approximately 640% more likely to have undiagnosed HIV, while those who are diagnosed are 53% less likely to have health insurance, 44% less likely to receive antiretroviral therapy, half as likely to adhere to their regimen and about half as likely to achieve an undetectable viral load.
Black MSM are the most impacted population in the U.S., and the toll of the disease among them is comparable to epidemics experienced in sub-Saharan Africa, Millett said. But he added that, contrary to many assumptions, the disproportionate impact is not due to a greater level of unsafe health practices. For instance, research indicates that black MSM have comparable rates of unprotected anal sex to white MSM, and are less likely to have multiple sex partners, he said.
And yet, "Between 2006 and 2009, the CDC found a 48% increase in new infections among young MSM, and the 'Brothers' study, discussed recently at the International AIDS Conference, found a 6% rate of HIV incidence among 1,500 black MSM who were under the age of 30," Millett said.
The CDC has thoroughly documented the severity of the epidemic, but researchers are still searching hard for an explanation, Millett suggested. According to published research discussed by Millett in his presentation, the most important factor associated with higher HIV prevalence among black MSM was having sex with a black partner. "There is a high background prevalence of HIV in black communities, and black MSM may be more likely to have contact with an infected partner," he explained.
One issue behind the disparity may have to do with sexuality disclosure, Millett said. He noted that patients who disclose to their primary care provider that they are gay or bisexual are more likely to receive HIV testing, as well as interventions such as hepatitis A and B vaccination, but that black MSM are 68% less likely to disclose their sexuality to a physician. Several studies show high levels of mistrust with health care professionals, which in turn may be associated with not taking HIV medications and missing clinical visits, said Millett, who added that black and Latino MSM are more likely to harbor conspiracy beliefs regarding the dangers posed by HIV medications, the link between HIV and AIDS, and the origin of HIV itself.
Other factors may be related to the finding that black MSM are more likely to have a young sexual debut, more likely to report childhood sex abuse and more likely have older sex partners, according to Millett. Black MSM are also more likely to have a lower level of education and income than the general population, he said, factors that have long been associated with higher HIV risk.
One important factor that is not related to the disproportionate impact of HIV on black MSM is substance use, according to Millett. "For some other suspect causes, like use of amphetamines -- which we know are associated with HIV, particularly in U.S. -- in study after study, we find that black MSM are 70% less likely to report they engage in crystal meth use. In terms of combining sex with drugs overall, black MSM are less likely to report using drugs during sex compared to other MSM," he said. However, black MSM are six times more likely to have a sexually transmitted infection, and they experienced an eight times greater increase in syphilis between 2005 and 2008, he noted.
According to one alarming study, HIV-infected black MSM who were unaware of their status were three times more likely than HIV-uninfected black MSM to have health insurance and three times more likely to have disclosed their sexuality to their physician, and yet were 94% less likely to have had more than three lifetime HIV tests, Millett said. This suggests a chasm in the provision of effective interventions on the part of the health care community.
Despite the bleak numbers, there are signs of interventions that can help turn the tide, Millett suggested. "We can achieve our goals in getting rid of some of these racial disparities," he said. "These are low-hanging fruit: If testing is not taking place among people who come to you and say, 'I'm an MSM,' and you're not testing them, that's an issue," he said. He also urged a greater level of effort among health care providers to discuss sexuality with their patients, and for providers in sexual health clinics to ramp up HIV testing and prevention among black MSM who present with other sexually transmitted infections.
On the HIV care front, Millett described a number of programs that showed promise in reducing disparities, such as contingency management intervention, a strategy that provides rewards for individuals who comply with medical directions.
"HIV-related disparities don't need to be a fait accompli in the U.S.," stressed Millett, noting that programs in the United Kingdom have shown efficacy at achieving outcomes among black, HIV-infected MSM that are similar to those among white MSM, once patients are diagnosed and placed into care. Some American programs have had similar success, he added, such as those at Kaiser Permanente and, most recently, in an integrated health care system in Baltimore that primarily cares for Ryan White patients.