A man injects himself with heroin using a needle. (David Ryder/Reuters)

Bringing down the rate of HIV infection in one of the United States’ great public health triumphs of the past quarter-century. Now, thanks to the opioid epidemic, some of those hard-won gains may be reversed.

Opioids, as well as being harmful on their own, also increase the risk of HIV outbreaks, as users sometimes inject the drugs using shared, infected syringes. That drove a clustered outbreak in Scott County, Indiana, where then-Governor Mike Pence declared a public health emergency in 2015 because of a spate of new HIV infections.

Hoping to prevent future outbreaks and to drive the HIV infection rate to zero, public health experts are holding a Capitol Hill summit Wednesday.

The summit’s organizer, the anti-HIV public health advocate amfAR, is rolling out a new website that assembles a wealth of data on the opioid epidemic and its relationship to HIV and other infectious diseases such as hepatitis C (HCV). This includes Centers for Disease Control and Prevention data on the 220 opioid addiction-racked U.S. counties which are most vulnerable to infectious disease outbreaks linked to injection drug use.

Source: Centers for Disease Control and Prevention data available at amfAR website

The vulnerable counties have high rates of poverty and unemployment, limiting their resources for providing services that can prevent or curtail outbreaks of infectious disease driven by injection drug abuse. Such services include syringe exchange programs and opioid agonist therapy with methadone or buprenorphine. One of the speakers at the summit, former Obama White House drug policy director Michael Botticelli, characterizes many of these counties as “treatment deserts.” But Botticelli also emphasizes that federal policy has helped compensate for local resource shortages. Most notably, the Medicaid expansion implemented by the 2010 Affordable Care Act “has greatly accelerated access to addiction treatment,” he says.

Such federal support may, however, be largely withdrawn if the Affordable Care Act is repealed. A disproportionate share of the most vulnerable counties are located in states represented by the Republican senators in whose hands the ACA’s fate most likely rests — including Sens. Rob Portman of Ohio, Shelley Moore Capito of West Virginia, Bob Corker and Lamar Alexander of Tennessee, Susan Collins and Olympia Snowe of Maine, and Dean Heller of Nevada. The risk that ACA repeal will put their constituents at greater risk both for increased opioid overdose deaths and HIV/HCV outbreaks should weigh heavily on these legislators’ minds.