Social and structural determinants of injecting-related bacterial and fungal infections among people who inject drugs: protocol for a mixed studies systematic review

Abstract

IntroductionInjecting-related bacterial and fungal infections are a common complication among people who inject drugs (PWID), associated with significant morbidity and mortality. Invasive infections, including infective endocarditis, appear to be increasing in incidence. To date, preventive efforts have focused on modifying individual-level risk behaviours (eg, hand-washing and skin-cleaning) without much success in reducing the population-level impact of these infections. Learning from successes in HIV prevention, there may be great value in looking beyond individual-level risk behaviours to the social determinants of health. Specifically, the risk environment conceptual framework identifies how social, physical, economic and political environmental factors facilitate and constrain individual behaviour, and therefore influence health outcomes. Understanding the social and structural determinants of injecting-related bacterial and fungal infections could help to identify new targets for prevention efforts in the face of increasing incidence of severe disease.Methods and analysisThis is a protocol for a systematic review. We will review studies of PWID and investigate associations between risk factors (both individual-level and social/structural-level) and the incidence of hospitalisation or death due to injecting-related bacterial infections (skin and soft-tissue infections, bacteraemia, infective endocarditis, osteomyelitis, septic arthritis, epidural abscess and others). We will include quantitative, qualitative and mixed methods studies. Using directed content analysis, we will code risk factors for these infection-related outcomes according to their contributions to the risk environment in type (social, physical, economic or political) and level (microenvironmental or macroenvironmental). We will also code and present risk factors at each stage in the process of drug acquisition, preparation, injection, superficial infection care, severe infection care or hospitalisation, and outcomes after infection or hospital discharge.Ethics and disseminationAs an analysis of the published literature, no ethics approval is required. The findings will inform a research agenda to develop and implement social/structural interventions aimed at reducing the burden of disease.PROSPERO registration numberCRD42021231411.

Unequal access to opioid agonist treatment and sterile injecting equipment among hospitalized patients with injection drug use-associated infective endocarditis

“…For patients with IDU-IE, unsafe injection drug use is the underlying cause of their infection and addiction treatment should be incorporated into treatment plans for secondary prevention [ 5 , 32 ]. All patients with IDU-IE in Halifax and 92% of patients with IDU-IE in Saint John reported opioid injection [ 33 ].…”

“…While one study identified an association between controlled-release hydromorphone prescriptions and IDU-IE in Ontario [ 64 ], a small minority of patients with IDU-IE in Ontario have recent prescriptions for hydromorphone [ 6 , 64 ]. Increasing rates of serious injection drug use-associated bacterial infections have been observed in many jurisdictions [ 4 , 5 ], and in Ontario appear to parallel transitions in the drug supply towards increasing use of illicitly-manufactured fentanyl [ 6 ]. Known risk factors for serious injecting-related infections include more frequent injecting (which has been associated with fentanyl and with stimulants), re-use of contaminated needles and filters, and subcutaneous injecting [ 65 ].…”

“…Known risk factors for serious injecting-related infections include more frequent injecting (which has been associated with fentanyl and with stimulants), re-use of contaminated needles and filters, and subcutaneous injecting [ 65 ]. Social determinants, including homelessness (impacting sterile drug preparation) and criminalization and policing practices (leading to rushed, subcutaneous injections), also influence risk [ 5 ]. We did not extract information on patients’ current or recent outpatient medication prescriptions to determine whether patients had recent prescriptions for these opioids, and we did not have reliable information on housing status.…”

“…Further, some of this confiscated equipment likely came from the publicly funded needle and syringe distribution programs in both cities; Halifax's program is located just a few blocks away from the hospital. Confiscating needles and syringes leads patients to hide and re-use blunted or contaminated injecting equipment, which increases the risk of bacterial infections including IDU-IE among hospitalized patients who inject drugs [5] and may also increase risk for needle-stick injuries among hospital staff [11,53]. Coupled with stigmatizing behaviours such as suspicion, surveillance, and restriction of pain medications, these approaches not only erode therapeutic relationships but are ineffective and can cause patients harm [22,50,[54][55][56][57][58].…”

“…North America's complex opioid-related public health crisis is associated with increasing rates of injection drug use [1], and a rapidly rising incidence of injecting-related bacterial and fungal infections, including injection drug use-associated infective endocarditis (IDU-IE) [2][3][4][5][6]. Hospitalization for IDU-IE is a "reachable moment" to effectively engage patients in addiction treatment and harm reduction care, including opioid agonist treatment (OAT; e.g.…”