"Even well-intentioned policies have exacerbated the link between opioid use and infectious disease. For instance, prescription drug monitoring programs and other measures to limit access to prescription opioids triggered a transition to heroin and, eventually, injection use among people who had become dependent on prescription pain relievers. At the same time, primary care clinics have not adequately screened, treated, and retained patients in treatment for substance use disorders. The resulting increase in the number of people who inject drugs has also increased the overall risk of infectious disease outbreaks. Other policies have similarly exacerbated the link between opioid use disorder and infectious diseases. For instance, policies that limit access to sterile syringes tend to increase infectious disease risk among people who inject drugs, as do the broad array of “war on drugs” policies that incarcerate individuals rather than connect them to treatment and harm-reduction programs. A number of studies have demonstrated that such programs—especially syringe services—lead to a net reduction in substance use through active referral, engagement, and retention in substance use disorder treatment."