Opioids and Infectious Diseases: A Converging Public Health Crisis

Abstract

A converging public health crisis is emerging because the opioid epidemic is fueling a surge in infectious diseases, such as human immunodeficiency virus infection with or without AIDS, the viral hepatitides, infective endocarditis, and skin and soft-tissue infections. An integrated strategy is needed to tailor preventive and therapeutic approaches toward infectious diseases in people who misuse and/or are addicted to opioids and to concurrently address the underlying predisposing factor for the infections—opioid use disorder. This commentary highlights the unique and complementary roles that the infectious diseases and substance use disorder communities can play in addressing this crisis of dual public health concerns.

The opioid epidemic is a major public health crisis that has impacted nearly every region and demographic group in the United States. The roots of this epidemic were established, in part, in the late 1990s, as prescribers increasingly used opioid analgesics to treat pain, including chronic pain, quadrupling the annual rate of opioid prescriptions between 1999 and 2010 [1]. Primarily because of the increased incidence of opioid use disorder (OUD) and the expanded presence of fentanyl analogs in the illicit opioid supply chain, nearly 400 000 people have died of overdoses involving opioids since 1999, with 47 600 deaths in 2017 alone [2].

Many individuals with OUD were initially prescribed oral opioids as analgesics and have shifted to injecting prescribed or illicit opioids [3]. The rise in OUD, bolstered by injection opioid use, conveys numerous downstream consequences and is fueling a surge in infectious diseases, such as human immunodeficiency virus (HIV) infection with or without AIDS, the viral hepatitides, infective endocarditis, and skin and soft-tissue infections [4, 5]. Thus, a converging public health crisis is arising that requires an integrated response by both infectious diseases specialists and substance use disorder (SUD) providers.

Here, we discuss some of the common opioid-associated infection risks and highlight the important and unique roles that the infectious diseases and SUD healthcare communities can collaboratively play to address the dual challenges of OUD and opioid-associated infectious diseases.

OPIOID-ASSOCIATED INFECTION RISKS

Driven by injection drug use (IDU), OUD and infectious diseases are inextricably linked. During IDU, viral infections (eg, HIV infection and hepatitis C virus [HCV] infection) are transmitted between individuals through high-risk injection practices, such as sharing syringes and drug paraphernalia and using high dead-space syringes. In 2016, injection opioid use was responsible for 13% of new HIV diagnoses and was linked to localized HIV outbreaks in Scott County, Indiana, and Lawrence and Lowell, Massachusetts [6, 7]. Transmission of HIV, HCV, and other sexually transmitted pathogens is also known to occur through IDU-associated sexual risk behaviors, including sex with multiple partners, unprotected sex with casual partners, and transactional sex [8]. Furthermore, contamination of the drugs themselves, drug injection paraphernalia, and the injection site with bacterial and fungal pathogens can cause infections at the site of injection (eg, cellulitis and skin abscesses) or at other sites in the body through hematogenous spread (eg, infective endocarditis and osteomyelitis) [9]. Notably, the increasing infection rates and demographic trends of bacterial and fungal infections appear to mirror trends observed with the opioid epidemic [10]. For example, the rate of methicillin-resistant Staphylococcus aureus infections among people who inject drugs more than doubled between 2011 and 2016 [11]. Additionally, growing evidence has shown that certain opioids (eg, morphine and fentanyl) have putative effects on both the innate and adaptive immune systems, dependent on drug dosage and duration of delivery. These effects have been shown to impact the pathogenesis of HIV and HCV infections in in vitro and animal models and may lead to higher rates of infections, such as pneumococcal pneumonia and other invasive pneumococcal diseases [12, 13]. However, a causal relationship between opioid use and immunosuppression has not been clearly established by definitive clinical trials. Furthermore, it has been demonstrated that poor intestinal flow caused by opioid use may be associated with increased risk of severe Clostridium difficile infection during inpatient treatment [14]. These risks and rates of infection will continue to affect people who inject drugs and those with OUD and will certainly increase in association with the opioid epidemic [5]. However, infectious diseases and SUD providers are each uniquely situated to address this converging public health crisis.

THE ROLE OF INFECTIOUS DISEASES PROVIDERS

The infectious diseases community has an essential role in addressing the converging opioid and infectious diseases challenge. Patients with IDU-associated infectious diseases often receive treatment for the infection by an infectious diseases provider who may not recognize and/or address the underlying cause—OUD [15]. Infectious diseases providers may find themselves on the front line for recognizing OUD, necessitating that they provide OUD treatment or refer the patient to an appropriate provider to care for the disorder. While this is a significant hurdle, made more challenging by the limited number of trained infectious diseases and OUD providers, it may have important implications for the treatment of the infectious disease. For example, coupling medication for OUD (including methadone or buprenorphine) with treatment of infectious diseases, such as HIV infection and HCV infection, remains a critical and effective strategy for preventing further transmission of these viral infections and improving retention in HIV and HCV care. Medication for OUD has repeatedly been demonstrated to reduce the frequency of opioid use, leading to a reduction of IDU-related risk behaviors associated with transmission of HIV and HCV [16]. Studies have also shown that coadministration of OUD medication and antiretroviral therapy (ART) is associated with increased uptake of ART, improved ART adherence, improved retention, and increased likelihood of HIV viral suppression [17]. Suppression of HIV viremia has clearly been associated with a dramatic decrease in transmissibility [18]. Therefore, infectious disease providers must be mindful that OUD is the driving force behind many infections associated with IDU and ensure that treatment is provided for this underlying disease, including medication for OUD and other harm-reduction interventions. Considering the limited capacity for addiction treatment in the United States, infectious diseases providers should also be encouraged to obtain a waiver to prescribe buprenorphine to close the gap in OUD treatment.

THE ROLE OF SUD HEALTHCARE PROVIDERS

SUD healthcare providers, including physicians, psychiatrists, psychologists, nurses, counselors, and social workers, are uniquely suited to identify risks for infectious diseases in conjunction with initiating OUD prevention or treatment strategies. Importantly, SUD healthcare providers may not consider the increased risks of infectious diseases in their patients. Just as infectious diseases physicians should be keenly aware of the possibility of OUD in their patients with infectious diseases, SUD providers should be alert to the possibility of unrecognized infectious diseases in their patients. For example, screening for and diagnosis of chronic viral infections, such as HIV infection and HCV infection, are low for patients with OUD, even among those in opioid treatment programs, in part because of systemic barriers (eg, staff capacity and organizational policies) [19]. Therefore, SUD providers should be encouraged to develop or use existing services to screen patients with OUD for infectious diseases, particularly those with a history of IDU, and should consult with infectious diseases providers to confer comprehensive treatment. In addition, SUD healthcare providers should be aware of and direct their patients to needle and syringe programs (NSPs), which have clearly been shown to decrease injection risks and enable administration of other services, such as testing for infectious diseases [20]. However, major shortages of NSPs and trained OUD providers exacerbates these challenges and contributes to low treatment rates. For example, in 2016, only about 11% of adults with a SUD had received any substance use treatment in the past year [21]. Investing in the SUD workforce, as well as expanding the NSPs to provide high coverage, would aid in combating this converging public health crisis.

THE ROLE OF THE FEDERAL GOVERNMENT

The US government continues to support treatment, prevention, surveillance, and research on OUD and recently reassessed opioid-related policies and dedicated additional resources to address the opioid epidemic. For example, the Centers for Disease Control and Prevention issued the Guideline for Prescribing Opioids for Chronic Pain to provide recommendations for opioid prescription practices, and the Substance Abuse and Mental Health Services Agency launched a nearly $1 billion initiative to expand access to evidence-based approaches to treating individuals with OUD [22, 23]. The National Institutes of Health also continues to support research aimed at understanding the biological mechanisms of and the best clinical approaches to treating OUD. Last year, the National Institutes of Health launched the HEAL (Helping to End Addiction Long-term) initiative, a $500 million trans-agency effort to improve pain management and enhance treatments for OUD [24]. In October 2018, Congress acknowledged and underscored the link between opioids and infectious diseases through passage of the SUPPORT (Substance Use–Disorder Prevention that Promotes Opioid Recovery and Treatment) for Patients and Communities Act. This bipartisan legislation addresses myriad aspects of the opioid epidemic and includes a provision to expand programs combating HCV infection to other opioid-related infectious diseases [25].

CONCLUSIONS

The growing trend of infectious diseases emerging across the United States in areas with high rates of opioid use has created a converging public health crisis with a significant combined impact on morbidity and mortality. The infectious diseases and SUD communities have important, overlapping, and optimally synergistic roles in addressing this crisis. Awareness of their potential partnership by both communities of healthcare providers is critical to the success of their individual efforts. Investment in evidence-based strategies from both fields, including expansion of medication for OUD and NSP and of the SUD workforce, are also of critical importance. A coordinated response by the infectious diseases and SUD communities, supported by the federal government and other organizations, will be imperative to contain and ultimately end the converging public health crisis of OUD and infectious diseases.

Notes

Potential conflicts of interest. All authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.

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