National HIV Testing Day today, June 27, follows recent revelations of an epidemic of new HIV diagnoses driven by the use of shared needles to inject opiate drugs in one small Indiana county. The Indiana outbreak reminds us that for all the progress this country has made against HIV, we continue to face formidable challenges in controlling the epidemic.

According to the Centers for Disease Control and Prevention, one in every seven people who are infected with HIV in the United States remains unaware of their infection. HIV testing – the crucial first step of the care continuum necessary to link individuals to the antiretroviral treatment that prevents illness and transmission – remains difficult, particularly for people who do not access traditional healthcare services.

As we have seen in Indiana, where new HIV diagnoses leaped from fewer than five in 2014 to nearly 170 in the first six months of this year, this lack of access includes people who struggle with addictions to opiate drugs. Opioid addiction is a growing problem across our country, where escalating rates of injection drug use have increased other health problems, including HIV, hepatitis C and other blood-borne diseases. It is a problem that not only affects people who inject drugs, but also the people with whom they have sex, who are often unaware that their partner’s behaviors are putting them at risk. These are some of the reasons, in spite of the remarkable advances in HIV prevention and treatment that our nation has led in the last decade, that we continue to see 50,000 new HIV infections every year in the United States.

State legislators and governors are starting to be guided by science and are supporting syringe exchange programs for people struggling with addictions. These critical programs reduce people’s risk of acquiring and transmitting HIV and other infectious diseases when injecting drugs. Syringe exchange programs also facilitate access to a range of services, including HIV and hepatitis C testing, substance use treatment, and other essential health and social services, including interventions to reduce overdose deaths. Implementation of these programs by Indiana and other states experiencing epidemics spawned by injection drug use have drawn attention to the federal funding ban on syringe programs. Thankfully, Congress has been evaluating the impact of the federal ban; we hope they will take action this year to allow federal support for this highly effective intervention that will help prevent more outbreaks like the one in Indiana.

Syringe exchange programs should be widely available in communities everywhere to prevent more public health crises. Lifting the federal ban on syringe exchange, fully and proactively, will prevent new infections, help link people who inject drugs to health and social services, and reduce risks to others. Lifting the ban would help us achieve new success by next year’s National HIV Testing Day by helping to turn the trajectory of the HIV epidemic at home.

Adimora is chair of the HIV Medicine Association and a professor of Medicine, School of Medicine, University of North Carolina, Chapel Hill.