Of the nearly 16 million injection drug users worldwide, approximately 3 million are living with HIV. And if sub-Saharan Africa is excluded, thirty percent of global HIV cases are attributed to injection drug use and in some cases is the main means of HIV transmission.
Dr. Nora Volkow, director of the National Institute on Drug Abuse, gave these statistics as she discussed the potential of antiretroviral therapy (ART) as prevention in addressing the epidemic among injection drug users Sunday session of the International AIDS Conference in Washington.
Noting an article by Julio Montaner in the Lancet in 2008, Volkow said aggressive efforts to seek out those difficult to reach populations to test and treat showed a profound effect on the virus levels in patients and a significant decrease in the number of new cases of HIV.
But the challenge for prevention of HIV with antiretroviral treatment among drug users starts with finding those individuals who are positive and don’t know their status, and sustaining them on treatment. A recent U.S. study that demonstrated a reluctance of physicians to treat injecting drug users with antiretroviral treatment, because they believed they would not comply with treatment regimens, Volkow said.
“For seventy percent of individuals who are IDU and HIV positive, physicians will defer their treatment,” she said. However, patients receiving treatment for their substance abuse are more adherent to antiretroviral treatment, she said.
A group in British Columbia found that if you aggressively treat with antiretroviral treatment and you treat for the injecting drug use disorder (using either methadone or buprenorphine), the mortality rate of HIV-infected individuals could not be distinguished between those using and those not using drugs. There was also a very dramatic decrease in incidence of resistant strains of the virus, showing that concomitant treatment for substance abuse can successfully treat HIV in injecting drug users.
But treatment for injecting drug use is hard to come by. In the U.S., Volkow said, less than 12 percent of opioid-dependent patients received opioid substitution therapy (OST) to treat their addiction. There is also minimal integration between HIV and substance use care in health care settings. Of the 2.2 million people per year who are incarcerated in the U.S., she said, 70 to 80 percent are in need of substance abuse treatment, and in 2010 only 1,600 opioid-dependent incarcerated people were receiving OST.
NIDA is developing new therapeutics for injecting drug users – like long-lasting medications to improve compliance, medications not based on opioid-substitution, and drug-abuse vaccines and other immuno-therapies.
Volkow said she was fortunate to hear Secretary of State Hilary Clinton speak at the National Institutes of Health in 2011, when she asked the audience members if they could imagine an AIDS free generation. “We can’t do that unless we address IDU and HIV,” Volkow said. That means implementation of “seek, test, treat and retain,” especially in countries and regions where injection drug use is the driver of the HIV epidemic, she said. There also must be a scale up of substance abuse treatment programs, integration of IDU care in other health care settings like clinics for sexually transmitted diseases, and addressing the treatment of IDU in the criminal justice system.
Audience member Joel Levin pointed out “a gaping hole” in her presentation: What about addressing Hepatitis C, which in the U.S. and countries where injecting drug use drives the HIV epidemic, is the leading cause of AIDS deaths? he asked.