Both localized and systemic bacterial infections are predicted by injection drug use: A prospective follow-up study in Swedish criminal justice clients

Water, sanitation and hygiene insecurity predict abscess incidence among people who inject drugs in a binational US-Mexico metropolitan area: A longitudinal cohort study

INTRODUCTION

People who inject drugs (PWID) are at high risk of developing injection-related infections, including abscesses. Access to water, sanitation, and hygiene (WASH) are key human rights and services; yet these services have been underexplored as predictors of abscesses among PWID.

METHODS

Longitudinal analysis was employed among a cohort of PWID to determine if WASH insecurity (lack of access) was associated with abscess incidence in the Tijuana, Mexico and San Diego, United States metropolitan area during 24-months of follow-up survey data from 2020 to 2023. We calculated abscess prevalence at baseline and tracked the incidence of new abscesses among individuals without an abscess during the previous visit. Time dependent Cox regression modeling was employed with variance clustered by participant to characterize the relationship between WASH insecurity and abscess incidence.

RESULTS

At baseline, hand hygiene insecurity, bathing insecurity in the previous six months and open defecation in the last week, were reported by 60 %, 54 % and 38 % of participants, respectively; 21 % reported an abscess in the last six months. The incidence of abscesses was 24.4 (95 %CI: 21.1-27.6) per 100 person-years. After adjusting for covariates, the hazard of developing an abscess remained significantly elevated among individuals using non-improved (with risk of contamination) water sources (e.g., surface water) for preparing drugs (adjusted HR [adjHR]: 1.49 [95 %CI: 1.01-2.21], experiencing bathing insecurity (adjHR: 1.59 [95 %CI: 1.12-2.24]) and open defecation (adjHR: 1.65 [95 %CI: 1.16-2.35]).

CONCLUSIONS

PWID in the Tijuana-San Diego metropolitan area reported facing high rates of insecurity accessing WASH services. Abscess incidence was higher (four to nine times) than observed rate among PWID cohorts in other settings. Access to continuously available toilet facilities, bathing infrastructure, and safe water sources for preparing drugs for injection could prevent abscesses among PWID. Accessible WASH infrastructure should be ensured among PWID communities and promoted as a key component of harm reduction infrastructure.

Mucocutaneous Manifestations of Recreational Drug Use

Recreational drug use is increasingly common in the dermatology patient population and is often associated with both general and specific mucocutaneous manifestations. Signs of substance use disorder may include changes to general appearance, skin, and mucosal findings associated with particular routes of drug administration (injection, insufflation, or inhalation) or findings specific to a particular drug. In this review article, we provide an overview of the mucocutaneous manifestations of illicit drug use including cocaine, methamphetamine, heroin, hallucinogens, marijuana, and common adulterants to facilitate the identification and improved care of these patients with the goal being to connect this patient population with appropriate resources for treatment.

Prevalence and incidence of emergency department presentations and hospital separations with injecting-related infections in a longitudinal cohort of people who inject drugs

People who inject drugs are at risk of acute bacterial and fungal injecting-related infections. There is evidence that incidence of hospitalizations for injecting-related infections are increasing in several countries, but little is known at an individual level. We aimed to examine injecting-related infections in a linked longitudinal cohort of people who inject drugs in Melbourne, Australia. A retrospective descriptive analysis was conducted to estimate the prevalence and incidence of injecting-related infections using administrative emergency department and hospital separation datasets linked to the SuperMIX cohort, from 2008 to 2018. Over the study period, 33% (95%CI: 31-36%) of participants presented to emergency department with any injecting-related infections and 27% (95%CI: 25-30%) were admitted to hospital. Of 1,044 emergency department presentations and 740 hospital separations, skin and soft tissue infections were most common, 88% and 76%, respectively. From 2008 to 2018, there was a substantial increase in emergency department presentations and hospital separations with any injecting-related infections, 48 to 135 per 1,000 person-years, and 18 to 102 per 1,000 person-years, respectively. The results emphasize that injecting-related infections are increasing, and that new models of care are needed to help prevent and facilitate early detection of superficial infection to avoid potentially life-threatening severe infections.

Assessment of Bacterial Infections and Antibiotic Regimens in Intravenous Drug Users

Bacterial infections in people who inject drugs (PWID) are a significant cause of hospitalizations and increased morbidity in this group. In this review, we evaluated bacterial trends in the most common infections and appropriate empiric antibiotic coverage. Articles from PubMed and Google Scholar were curated in a Google document with shared access. Discussion and development of the paper were achieved over Zoom meetings. The common infections in PWID were skin and soft tissue infections (SSTIs), infective endocarditis, septic arthritis, osteomyelitis, and bloodstream infections (BSIs). The presence of comorbidities increased susceptibility to bacterial infections. Staphylococcus aureus was the predominant species in all the infections and included methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). The current standard of antibiotic use for Staphylococcus species was found to be sufficient. The gram-negative bacillus Serratia marcescens was prevalent in PWID as a causative agent of septic arthritis, osteomyelitis, and infective endocarditis. Its treatment required a combination of β-lactam and either a fluoroquinolone or an aminoglycoside for a prolonged duration. Streptococci were commonly implicated in SSTIs and BSIs. The appropriate response was seen with β-lactam antibiotics. In PWID, Enterococcus and Pseudomonas were implicated in infective endocarditis of native and prosthetic valves. The former being difficult to treat, a new strategy of using dual β-lactam antibiotics was found to be supported by clinical data. Anti-pseudomonal antibiotics can be avoided in other infections seen in this group, as their prevalence was low. PWID, especially those with comorbidities, have an increased risk of acquiring infections with difficult-to-treat microbes. Therefore, empiric antibiotic treatment should be relevant to the infection, for which bacterial trends and antibiotic susceptibility must be reassessed periodically.

A review on circular RNAs and bacterial infections

Bacterial infections and related diseases have been a major burden on social public health and economic stability around the world. However, the effective diagnostic methods and therapeutic approaches to treat bacterial infections are still limited. As a group of non-coding RNA, circular RNAs (circRNAs) that were expressed specifically in host cells and played a key regulatory role have the potential to be of diagnostic and therapeutic value. In this review, we systematically summarize the role of circRNAs in common bacterial infections and their potential roles as diagnostic markers and therapeutic targets.

Necrotizing Soft Tissue Infection Secondary to Streptococcus constellatus, Actinomyces odontolyticus, and Gemella morbillorum in an Intravenous Drug User: A Case Report and Literature Review

A 53-year-old male with active IV heroin use presented with left upper extremity pain, erythema, swelling, and purulent foul-smelling drainage. Rapid diagnosis of necrotizing soft tissue infection (NSTI) was made based on clinical and radiologic findings. He was taken to the operating room for wound washouts and surgical debridements. The early microbiologic diagnosis was made based on intraoperative cultures. Successful treatment of NSTI in the setting of rare pathogens was achieved. The wound was ultimately treated with wound vac therapy, followed by primary delayed closure of the upper extremity and skin grafting of the forearm. We present a case of NSTI secondary to Streptococcus constellatus, Actinomyces odontolyticus, and Gemella morbillorum in an intravenous (IV) drug user, successfully treated with early surgical intervention.

Implementation of an integrated infectious disease and substance use disorder team for injection drug use-associated infections: a qualitative study

BACKGROUND

Hospitalizations for severe injection drug use-related infections (SIRIs) are characterized by high costs, frequent patient-directed discharge, and high readmission rates. Beyond the health system impacts, these admissions can be traumatizing to people who inject drugs (PWID), who often receive inadequate treatment for their substance use disorders (SUD). The Jackson SIRI team was developed as an integrated infectious disease/SUD treatment intervention for patients hospitalized at a public safety-net hospital in Miami, Florida in 2020. We conducted a qualitative study to identify patient- and clinician-level perceived implementation barriers and facilitators to the SIRI team intervention.

METHODS

Participants were patients with history of SIRIs (n = 7) and healthcare clinicians (n = 8) at one implementing hospital (Jackson Memorial Hospital). Semi-structured qualitative interviews were performed with a guide created using the Consolidated Framework for Implementation Research (CFIR). Interviews were transcribed, double coded, and categorized by study team members using CFIR constructs.

RESULTS

Implementation barriers to the SIRI team intervention identified by participants included: (1) complexity of the SIRI team intervention; (2) lack of resources for PWID experiencing homelessness, financial insecurity, and uninsured status; (3) clinician-level stigma and lack of knowledge around addiction and medications for opioid use disorder (OUD); and (4) concerns about underinvestment in the intervention. Implementation facilitators of the intervention included: (1) a non-judgmental, harm reduction-oriented approach; (2) the team's advocacy for PWID as a means of institutional culture change; (3) provision of close post-hospital follow-up that is often inaccessible for PWID; (4) strong communication with patients and their hospital physicians; and (5) addressing diverse needs such as housing, insurance, and psychological wellbeing.

CONCLUSION

Integration of infectious disease and SUD treatment is a promising approach to managing patients with SIRIs. Implementation success depends on institutional buy-in, holistic care beyond the medical domain, and an ethos rooted in harm reduction across multilevel (inner and outer) implementation contexts.

Acute injection-related infections requiring hospitalisation among people who inject drugs: Clinical features, microbiology and management

INTRODUCTION

People who inject drugs are at risk of hospitalisation with injection-related infections (IRI). We audited the clinical features, microbiology and management of IRI at a tertiary service in Melbourne to describe the burden and identify quality improvement opportunities.

METHODS

We performed retrospective review of IRI admissions from January 2017 to April 2019. We extracted admissions where ICD-10 codes or triage text suggested injecting drug use, and the diagnosis suggested IRI. We reviewed these for eligibility and extracted data using a standardised form. We performed mixed-effects logistic regression to determine predictors of unplanned discharge.

RESULTS

From 574 extracted candidate admissions, 226 were eligible, representing 178 patients. Median age was 41 years (interquartile range 36-47), 66% (117/178) male and 49% (111/226) had unstable housing. Over 50% (96/178) had a psychiatric diagnosis and 35% (62/178) were on opioid agonist therapy (OAT) on admission. Skin and soft tissue infection was the most common IRI (119/205, 58%), followed by bacteraemia (36/205, 18%) and endocarditis (26/205, 13%). Management included addictions review (143/226, 63%), blood-borne virus screening (115/226, 51%), surgery (77/226, 34%) and OAT commencement (68/226, 30%). Aggression events (54/226, 15%) and unplanned discharge (69/226, 30%) complicated some admissions. Opioid use without OAT was associated with almost 3-fold increased odds of unplanned discharge compared to no opioid use (odds ratio 2.90, 95% confidence interval 1.23, 6.85, p = 0.015).

DISCUSSION AND CONCLUSION

Comorbidities associated with IRI may be amenable to opportunistic intervention during hospitalisation. Further research is needed to develop optimal models of care for this vulnerable patient group.

Wounds and Skin and Soft Tissue Infections in People Who Inject Drugs and the Utility of Syringe Service Programs in Their Management

Significance: Opioid use disorder and transition to injection drug use (IDU) are an urgent, nationwide public health crisis. Wounds and skin and soft tissue infections (SSTIs) are common complications of IDU that disproportionately affect people who inject drugs (PWID) and are a major source of morbidity and mortality for this population. Critical Issues: Injections in a nonsterile environment and reusing or sharing needles facilitates bacterial inoculation, with subsequent risk of serious complications such as sepsis, gangrene, amputation, and death. PWID are susceptible to infections with a wide spectrum of organisms beyond common culprits of SSTI, including Clostridium and Bacillus spp., as well as Candida. Recent Advances: Syringe services programs (SSPs) are cost-effective and successful in reducing harms associated with IDU. SSPs provide new equipment to PWID and aid in discarding used equipment. SSPs aim to reduce the risks of unhygienic injecting practices, which are associated with transmission of infections and blood-borne pathogens. Future Directions: Concurrently run SSPs and wound care clinics are uniquely positioned to facilitate care to PWID. Providing new, sterile equipment as well as early wound care intervention can reduce morbidity and mortality as well as health care expenditures by reducing the number of SSTI and injection-related wounds that require hospital admission. Establishment of wound care clinics as part of an SSP represents an untapped potential to reduce harm.

Injecting drug use, the skin and vasculature

Damage to the skin, subcutaneous tissues and blood vessels are among the most common health harms related to injecting drug use. From a limited range of early reports of injecting-related skin and soft tissue damage there is now an increasing literature relating to new drugs, new contaminants and problems associated with unsafe injection practices. Clinical issues range from ubiquitous problems associated with repeated minor localised injection trauma to skin and soft tissue and infections around injection sites, to systemic blood infections and chronic vascular disease. The interplay of limited availability and access to sterile injecting equipment, poor injecting technique, compromised drug purity, drug toxicity and difficult personal and environmental conditions give rise to injection-related health harms. This review of injecting-related skin, soft tissue and vascular damage focuses on epidemiology and causation, clinical examination and investigation, treatment and prevention.

Recurring Severe Injection-Related Infections in People Who Inject Drugs and the Need for Safe Injection Sites in Madrid, Spain

BACKGROUND

An estimated 58 749 people with opioid use disorder engaged in opioid agonist therapy (OAT) in 1132 centers in Spain during 2017. We aimed to calculate the incidence of severe injection-related infections in people who inject drugs (PWID) engaged in OAT in harm reduction settings without a safe consumption space.

METHODS

A retrospective cohort study was performed in PWID engaged in OAT and in a mobile harm reduction unit to quantify admissions to a referral hospital for any severe injection-related infections between 1 January 2016 and 31 December 2019. A Cox proportional hazard regression analysis was used to assess factors associated with any severe injection-related infection.

RESULTS

Two hundred thirty-seven PWID who engaged in OAT were included in the study. After a median follow-up of 5.5 months (interquartile range [IQR], 1.3-22.7 months), a total of 104 episodes of severe injection-related infections occurred among 56 individuals, and admission due to a second event occurred in 35.7% of this same group. The incidence density of any type of severe injection-related infection was 26.8 (95% confidence interval [CI], 20.2-34.8) episodes per 100 person-years, and the incidence density of complicated skin and soft tissue infections that required hospital admission was 20.4 (95% CI, 15.0-27.3) episodes per 100 person-years. Fifty-six (53.8%) of all the episodes were patient-directed discharge (PDD), and people who had 2 or more hospital admissions had a higher PDD frequency.

CONCLUSIONS

Severe injection-related infections remain highly prevalent among PWID cared for in a harm reduction setting without a safe consumption space. PDD was more frequent among higher-risk individuals who presented 2 or more hospital readmissions.

Bacterial infections in people who inject psychoactive substances: An observational study in a French university hospital

AIM OF THE STUDY

To describe bacterial infections in injection drug users (IDUs) hospitalized at Montpellier University Hospital, France, and to identify factors that might influence the development of local or systemic infections.

METHODS

This cross-sectional observational monocentric study prospectively included bacterial infections in IDUs hospitalized at Montpellier University Hospital between 2012 and 2018. Types of infection (local or systemic) were described and compared to identify specific features (injection practices).

RESULTS

The study included 144 bacterial infections (56% of local infections and 44% of systemic infections) concerning 117 IDUs. The most common infection types were abscesses (50%), skin and soft tissue infections (33%), bacteremia/sepsis (20%), endocarditis (17%), and bone and joint infections (16%). Patients were mainly men (n=94; 80%), and the median age was 40 years [IQR_25-75: 34-47]. Four deaths related to systemic infection were reported. The most frequent injected substances were cocaine, opioid maintenance treatments (OMT), and opioids. According to the multivariate analysis, factors associated with the occurrence of systemic infections were number of injection (OR 2.59 [1.07-6.27]; P=0.034) and injection of at least one opioid (OR 3.52 [1.28-9.72]; P=0.015).

CONCLUSION

Different types of bacterial infections, local or systemic, are observed in IDUs. Skin infections are quite common, but other infection types also are reported, with sometimes serious consequences. It is already known that injection practices are contributing factors in infection development, but the type of injected psychoactive substance(s) also may have an influence.

Association between discharges against medical advice and readmission in patients treated for drug injection-related skin and soft tissue infections

BACKGROUND

The prevalence of injection drug use (IDU)-related skin and soft tissue infections (SSTI) in Philadelphia has been steadily increasing since 2013. Patients seeking treatment for these infections are more likely to be discharged against medical advice (AMA), increasing the likelihood that they will end antibiotic treatment prematurely and require additional medical interventions.

METHODS

The research team performed a nested case-control study using the Pennsylvania Health Care Cost Containment Council database for Philadelphia residents hospitalized for SSTI and substance use-related diagnoses between 2013 and 2018. The primary outcome was readmission in the same or following quarter. The study examined the impact of discharge AMA on readmission along with clinical characteristics including diagnoses for anxiety, bipolar disorder, depression, schizophrenia, diabetes, and polydrug use.

RESULTS

There were 8265 hospitalizations for IDU-related SSTI and 316 (6%) were readmitted to the hospital at least once in the same or following quarter. In total, 23.4% of cases and 13% of controls left AMA. In the final multivariable regression model, AMA discharge (AOR 2.04, 95% CI 1.46-2.86), anxiety (AOR 1.44, 95% CI 1.01-2.05), diabetes (AOR 2.02, 95% CI 1.46-2.81), and polydrug use (AOR 2.11, 95% CI 1.52-2.92) were associated with higher odds of readmission.

CONCLUSIONS

Our study demonstrates that readmissions for IDU-related SSTI are associated with recent discharge AMA. As IDU-related SSTI and polydrug use continue to rise, premature antibiotic treatment completion will impact more people, leading to worse health outcomes and additional strain on the health care system.

Soft Tissue, Bone, and Joint Infections in People Who Inject Drugs

Infections are a common complication among people who inject drugs (PWID). Skin and soft tissue infections (SSTI) as well as bone and joint infections comprise a significant source of morbidity and mortality among this population. The appropriate recognition and management of these infections are critical for providers, as is familiarity with harm-reduction strategies. This review provides an overview of the presentation and management of SSTI and bone and joint infections among PWID, as well as key prevention measures that providers can take.

Recent Innovations in Bacterial Infection Detection and Treatment

Bacterial infections are a major threat to human health, exacerbated by increasing antibiotic resistance. These infections can result in tremendous morbidity and mortality, emphasizing the need to identify and treat pathogenic bacteria quickly and effectively. Recent developments in detection methods have focused on electrochemical, optical, and mass-based biosensors. Advances in these systems include implementing multifunctional materials, microfluidic sampling, and portable data-processing to improve sensitivity, specificity, and ease of operation. Concurrently, advances in antibacterial treatment have largely focused on targeted and responsive delivery for both antibiotics and antibiotic alternatives. Antibiotic alternatives described here include repurposed drugs, antimicrobial peptides and polymers, nucleic acids, small molecules, living systems, and bacteriophages. Finally, closed-loop therapies are combining advances in the fields of both detection and treatment. This review provides a comprehensive summary of the current trends in detection and treatment systems for bacterial infections.

Correlates of injection-related wounds and skin infections amongst persons who inject drugs and use a syringe service programme: A single center study

Risk factors associated with wounds and skin infections amongst persons who inject drugs may have changed in the era of fentanyl and now stimulant coinjection. We assessed the number of injection site wounds and skin infections and associated factors amongst 675 persons who inject drugs in a syringe services programme. Of this sample, 173 participants reported a total of 307 wounds and skin infections. Significant factors associated with increased number of wounds and skin infections were age 30 or older, female gender, ever experiencing homelessness, cocaine injection, and injecting between 5 and 10 years. Wounds and skin infections were common amongst syringe services programme clients and are associated with certain risk factors that may help to design effective interventions. Given the high prevalence of wounds in syringe services programme clients, wound care clinicians can make a significant difference and improve outcomes. We also shed light on correlates of wounds and skin infections in persons who inject drugs in order to spur further research to devise efficacious interventions for this underserved group.

Evaluation of Infectious Disease Test Ordering and Positivity Rates in Illicit Fentanyl Users

BACKGROUND

The emergence of illicit fentanyl use has resulted in considerable morbidity and mortality. Although illicit use of other opioids has been associated with transmission of viral and bacterial infections, limited data exist for the prevalence of infectious diseases among illicit fentanyl users. The purpose of this study was to assess the likelihood of infectious disease testing and infection prevalence among illicit fentanyl users.

METHODS

Results from urine drug screens (UDSs) performed from August 13, 2019, to October 16, 2019, were obtained from the laboratory information system with concurrent microbial testing. Patients were categorized based on UDS results, and illicit drug use was inferred from physician encounter notes in the electronic medical record.

RESULTS

Suspected illicit drugs users with fentanyl detected by UDS were more likely to be screened [odds ratio (OR): 1.7; 95% CI, 1.26-2.4] and test positive for hepatitis C virus (HCV) by immunoassay (OR: 5.89; 95% CI, 2.93-11.31) than patients without drugs detected. Patients with suspected illicit fentanyl use who were discharged from the emergency department (ED) were less likely to be tested for HCV than patients in outpatient settings (OR: 3.47; 95% CI, 1.05-10.4) and inpatient settings (OR: 17.43; 95% CI, 6.53-45.88). Patients with suspected illicit fentanyl use were more likely to have infected abscesses or wounds (OR: 5.12; 95% CI, 2.07-13.7) and Staphylococcus aureus infections (OR: 4.5; 95% CI, 1.59-12.28) than patients without drugs detected.

CONCLUSIONS

Patients with a positive UDS for fentanyl and suspected illicit use were more likely to test positive for HCV, were rarely screened for HCV in the ED, and had an increased risk of invasive S. aureus wound or abscess infection. These findings may represent considerable barriers to care for patients who use fentanyl illicitly.

Skin and Soft Tissue Infections in Persons Who Inject Drugs

Persons who inject drugs are at high risk for skin and soft tissue infections. Infections range from simple abscesses and uncomplicated cellulitis to life-threatening and limb-threatening infections. These infections are predominantly caused by gram-positive organisms with Staphylococcus aureus, Streptococcus pyogenes, and other streptococcal species being most common. Although antimicrobial therapy has an important role in treatment of these infections, surgical incision, drainage, and debridement of devitalized tissue are primary. Strategies that decrease the frequency of injection drug use, needle sharing, use of contaminated equipment, and other risk behaviors may be effective in preventing these infections in persons who inject drugs.

Incidence and treatment costs of severe bacterial infections among people who inject heroin: A cohort study in South London, England

BACKGROUND

People who inject drugs often get bacterial infections. Few longitudinal studies have reported the incidence and treatment costs of these infections.

METHODS

For a cohort of 2335 people who inject heroin entering treatment for drug dependence between 2006 and 2017 in London, England, we reported the rates of hospitalisation or death with primary causes of cutaneous abscess, cellulitis, phlebitis, septicaemia, osteomyelitis, septic arthritis, endocarditis, or necrotising fasciitis. We compared these rates to the general population. We also used NHS reference costs to calculate the cost of admissions.

RESULTS

During a median of 8.0 years of follow-up, 24 % of patients (570/2335) had a severe bacterial infection, most commonly presenting with cutaneous abscesses or cellulitis. Bacterial infections accounted for 13 % of all hospital admissions. The rate was 73 per 1000 person-years (95 % CI 69-77); 50 times the general population, and the rate remained high throughout follow-up. The rate of severe bacterial infections for women was 1.50 (95 % CI 1.32-1.69) times the rate for men. The mean cost per admission was £4980, and we estimate that the annual cost of hospital treatment for people who inject heroin in London is £4.5 million.

CONCLUSIONS

People who inject heroin have extreme and long-term risk of severe bacterial infections.

Self-care habits among people who inject drugs with skin and soft tissue infections: a qualitative analysis

BACKGROUND

Injection drug use is on the rise in the USA, and skin and soft tissue infections (SSTI) are a common complication, resulting in significant morbidity and mortality. Due to structural barriers to care-seeking, many people who inject drugs avoid formal care and resort to self-care techniques, but little is known about the nature of these techniques, or more generally about the accuracy or breadth of this population's knowledge of SSTIs.

METHODS

Semi-structured qualitative interviews were conducted with 12 people who inject heroin in two metropolitan areas: Sacramento and Boston, USA.

RESULTS

These interviews reveal a robust and accurate knowledge base regarding skin infections, including the progression from simple cellulitis to an abscess, and acknowledgment of the possibility of serious infections. Nonetheless, there remains a reticence to seek care secondary to past traumatic experiences. A step-wise approach to self-care of SSTI infections was identified, which included themes of whole-body health, topical applications, use of non-prescribed antibiotics, and incision and drainage by non-medical providers.

CONCLUSIONS

The reported SSTI self-care strategies demonstrate resilience and ingenuity, but also raise serious concerns about inappropriate antibiotic consumption and complications of invasive surgical procedures performed without proper training, technique, or materials. Harm reduction agencies and health care providers should work to obviate the need for these potentially dangerous practices by improving healthcare access for this population. In the absence of robust solutions to meet the needs of this population, education materials should be developed to optimize the efficacy and minimize the harms of these practices, while empowering and supporting the autonomy of people who use drugs and providing clear guidance on when self-care should be abandoned in favor of formal medical care.

Substance Abuse–Related Soft Tissue Infections: A Uniquely Complicated Subset of a Common Problem

We hypothesize that soft tissue infections (SSIs) related to intravenous drug usage (IVDU) are associated with a more complicated and costly course than those not associated with IVDU. For the period 2005–2018, ICD 9/ICD 10 billing codes were used to identify patients admitted with SSIs and their causes/complications and associated costs. IVDU-related infections were then compared with non-IVDU–related infections. t test was used to compare treatment costs and length of stay. Logistic regression analysis was used to assess the likelihood/risk of specific events in the IVDU versus non-IVDU populations. Of 47,281 patients admitted with SSIs, 1323 were associated with IVDU. IVDU-related patients tended to be younger (36.2 vs 49.3 years, P = 0.001). Both cost and length of stay were significantly greater in the IVDU group ($30,471 vs $16,020, P = 0.001; 5.7days vs 3.7days, P = 0.001). In addition, IVDU admissions were more likely to be associated with chronic blood-borne infections (hepatitis B/C, HIV, P = 0.001) and a significantly greater incidence of secondary infectious complications, including endocarditis ( P = 0.001), bacteremia ( P = 0.001), and osteomyelitis ( P = 0.003). SSI admissions related to IVDU are a unique subgroup of patients. These patients not only have longer and more costly lengths of stay but are also at higher risk for secondary complications such as chronic blood-borne viral illness and secondary bacterial infectious complications, such as bacteremia, endocarditis, and osteomyelitis. Further prospective study of these findings is warranted as we continue to battle the growing problem of IVDU in the United States

Association of Methadone Treatment With Substance-Related Hospital Admissions Among a Population in Canada With a History of Criminal Convictions

IMPORTANCE

People with criminal histories experience high rates of opioid dependence and are frequent users of acute health care services. It is unclear whether methadone adherence prevents hospitalizations.

OBJECTIVE

To compare hospital admissions during medicated and nonmedicated methadone periods.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study involving linked population-level administrative data among individuals in British Columbia, Canada, with provincial justice contacts (n= 250 884) and who filled a methadone prescription between April 1, 2001, and March 31, 2015. Participants were followed from the date of first dispensed methadone prescription until censoring (date of death, or March 31, 2015). Data analysis was conducted from May 1 to August 31, 2018.

EXPOSURES

Methadone treatment was divided into medicated (methadone was dispensed) and nonmedicated (methadone was not dispensed) periods and analyzed as a time-varying exposure.

MAIN OUTCOME AND MEASURES

Adjusted hazard ratios (aHRs) of acute hospitalizations for any cause and cause-specific (substance use disorder [SUD], non-substance-related mental disorders [NSMDs], and medical diagnoses [MEDs]) were estimated using multivariable Cox proportional hazards regression.

RESULTS

A total of 11 401 people (mean [SD] age, 34.9 [9.4] years; 8230 [72.2%] men) met inclusion criteria and were followed up for a total of 69 279.3 person-years. During a median follow-up time of 5.5 years (interquartile range, 2.8-9.1 years), there were 19 160 acute hospital admissions. Dispensed methadone was associated with a 50% lower rate of hospitalization for any cause (aHR, 0.50; 95% CI, 0.46-0.53) during the first 2 years (≤2.0 years) following methadone initiation, demonstrating significantly lower rates of admission for SUD (aHR, 0.32; 95% CI, 0.27-0.38), NSMD (aHR, 0.41; 95% CI, 0.34-0.50), and MED (aHR, 0.57; 95% CI, 0.52-0.62). As duration of time increased (2.1 to ≤5.0 years; 5.1 to ≤10.0 years), methadone was associated with a significant but smaller magnitude of effect: SUD (aHR, 0.43; 95% CI, 0.36-0.52; aHR, 0.47; 95% CI, 0.37-0.61), NSMD (aHR, 0.51; 95% CI, 0.41-0.64; aHR, 0.60; 95% CI, 0.47-0.78), and MED (aHR, 0.71; 95% CI, 0.65-0.77; aHR, 0.85; 95% CI, 0.76-0.95).

CONCLUSIONS AND RELEVANCE

In this study, methadone was associated with a lower rate of hospitalization among a large cohort of Canadian individuals with histories of convictions and prevalent concurrent health and social needs. Practices to improve methadone adherence are warranted.