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

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.

REPAIRS Delphi: A UK and Ireland Consensus Statement on the Management of Infected Arterial Pseudoaneurysms Secondary to Groin Injecting Drug Use

OBJECTIVE

Consensus guidelines on the optimal management of infected arterial pseudoaneurysms secondary to groin injecting drug use are lacking. This pathology is a problem in the UK and globally, yet operative management options remain contentious. This study was designed to establish consensus to promote better management of these patients, drawing on the expert experience of those in a location with a high prevalence of illicit drug use.

METHODS

A three round modified Delphi was undertaken, systematically surveying consultant vascular surgeons in the UK and Ireland using an online platform. Seventy five vascular surgery units were invited to participate, with one consultant providing the unit consensus practice. Round one responses were thematically analysed to generate statements for round two. These statements were evaluated by participants using a five point Likert scale. Consensus was achieved at a threshold of 70% or more agreement or disagreement. Those statements not reaching consensus were assessed and modified for round three. The results of the Delphi process constituted the consensus statement.

RESULTS

Round one received 64 (86%) responses, round two 59 (79%) responses, and round three 62 (83%) responses; 73 (97%) of 75 units contributed. Round two comprised 150 statements and round three 24 statements. Ninety one statements achieved consensus agreement and 15 consensus disagreement. The Delphi statements covered sequential management of these patients from diagnosis and imaging, antibiotics and microbiology, surgical approach, wound management, follow up, and additional considerations. Pre-operative imaging achieved consensus agreement (97%), with computerised tomography angiography being the modality of choice (97%). Ligation and debridement without arterial reconstruction was the preferred approach at initial surgical intervention (89%). Multidisciplinary management, ensuring holistic care and access to substance use services, also gained consensus agreement.

CONCLUSION

This comprehensive consensus statement provides a strong insight into the standard of care for these patients.

Epidemiology of acute infections in people who inject drugs in Australia

ISSUES

People who inject drugs are at risk of acute infections, such as skin and soft tissue infections, infective endocarditis, bone and joint infections and bloodstream infections. There has been an increase in these infections in people who inject drugs internationally over the past 10 years. However, the local data regarding acute infections in Australia has not been well described.

APPROACH

We review the epidemiology of acute infections and associated morbidity and mortality amongst people who inject drugs in Australia. We summarise risk factors for these infections, including the concurrent social and psychological determinants of health.

KEY FINDINGS

The proportion of people who report having injected drugs in the prior 12 months in Australia has decreased over the past 18 years. However, there has been an increase in the burden of acute infections in this population. This increase is driven largely by skin and soft tissue infections. People who inject drugs often have multiple conflicting priorities that can delay engagement in care.

IMPLICATIONS

Acute infections in people who inject drugs are associated with significant morbidity and mortality. Acute infections contribute to significant bed days, surgical requirements and health-care costs in Australia. The increase in these infections is likely due to a complex interplay of microbiological, individual, social and environmental factors.

CONCLUSION

Acute infections in people who inject drugs in Australia represent a significant burden to both patients and health-care systems. Flexible health-care models, such as low-threshold wound clinics, would help directly target, and address early interventions, for these infections.

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.

Opioid Injection-Associated Bacterial Infections in England, 2002-2021: A Time Series Analysis of Seasonal Variation and the Impact of Coronavirus Disease 2019

BACKGROUND

Bacterial infections cause substantial pain and disability among people who inject drugs. We described time trends in hospital admissions for injecting-related infections in England.

METHODS

We analyzed hospital admissions in England between January 2002 and December 2021. We included patients with infections commonly caused by drug injection, including cutaneous abscesses, cellulitis, endocarditis, or osteomyelitis, and a diagnosis of opioid use disorder. We used Poisson regression to estimate seasonal variation and changes associated with coronavirus disease 2019 (COVID-19) response.

RESULTS

There were 92 303 hospital admissions for injection-associated infections between 2002 and 2021. Eighty-seven percent were skin, soft-tissue, or vascular infections; 72% of patients were male; and the median age increased from 31 years in 2002 to 42 years in 2021. The rate of admissions reduced from 13.97 per day (95% confidence interval [CI], 13.59-14.36) in 2003 to 8.94 (95% CI, 8.64-9.25) in 2011, then increased to 18.91 (95% CI, 18.46-19.36) in 2019. At the introduction of COVID-19 response in March 2020, the rate of injection-associated infections reduced by 35.3% (95% CI, 32.1-38.4). Injection-associated infections were also seasonal; the rate was 1.21 (95% CI, 1.18-1.24) times higher in July than in February.

CONCLUSIONS

This incidence of opioid injection-associated infections varies within years and reduced following COVID-19 response measures. This suggests that social and structural factors such as housing and the degree of social mixing may contribute to the risk of infection, supporting investment in improved social conditions for this population as a means to reduce the burden of injecting-related infections.

Epidemiology and Management of invasive infections among people who Use drugs (EMU): protocol for a prospective, multicentre cohort study

INTRODUCTION

People who inject drugs (PWID) are at risk of invasive infections such as bloodstream infections, endocarditis, osteomyelitis and septic arthritis. Such infections require prolonged antibiotic therapy, but there is limited evidence about the optimal care model to deliver to this population. The Epidemiology and Management of invasive infections among people who Use drugs (EMU) study aims to (1) describe the current burden, clinical spectrum, management and outcomes of invasive infections in PWID; (2) determine the impact of currently available models of care on completion of planned antimicrobials for PWID admitted to hospital with invasive infections and (3) determine postdischarge outcomes of PWID admitted with invasive infections at 30 and 90 days.

METHODS AND ANALYSIS

EMU is a prospective multicentre cohort study of Australian public hospitals who provide care to PWIDs with invasive infections. All patients who have injected drugs in the previous six months and are admitted to a participating site for management of an invasive infection are eligible. EMU has two components: (1) EMU-Audit will collect information from medical records, including demographics, clinical presentation, management and outcomes; (2) EMU-Cohort will augment this with interviews at baseline, 30 and 90 days post-discharge, and data linkage examining readmission rates and mortality. The primary exposure is antimicrobial treatment modality, categorised as inpatient intravenous antimicrobials, outpatient antimicrobial therapy, early oral antibiotics or lipoglycopeptide. The primary outcome is confirmed completion of planned antimicrobials. We aim to recruit 146 participants over a 2-year period.

ETHICS AND DISSEMINATION

EMU has been approved by the Alfred Hospital Human Research Ethics Committee (Project number 78815.) EMU-Audit will collect non-identifiable data with a waiver of consent. EMU-Cohort will collect identifiable data with informed consent. Findings will be presented at scientific conferences and disseminated by peer-review publications.

TRIAL REGISTRATION NUMBER

ACTRN12622001173785; Pre-results.

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.

The impact of opioid agonist treatment on hospitalisations for injecting-related diseases among an opioid dependent population: A retrospective data linkage study

BACKGROUND

Injecting-related bacterial and fungal infections cause substantial illness and disability among people who use illicit drugs. Opioid agonist treatment (OAT) reduces injecting frequency and the transmission of blood borne viruses. We estimated the impact of OAT on hospitalisations for non-viral infections and examine trends in incidence over time.

METHODS

We conducted a retrospective cohort study using linked administrative data. The cohort included 47 163 individuals starting OAT between August 2001 and December 2017 in New South Wales, Australia, with 454 951 person-years of follow-up. The primary outcome was hospitalisation for an injecting-related disease. The primary exposure was OAT status (out of OAT, first four weeks of OAT, and OAT retention [i.e., more than four weeks in treatment]). Covariates included demographic characteristics, year of hospitalisation, and recent clinical treatment.

RESULTS

9122 participants (19.3%) had at least one hospitalisation for any injecting-related disease. Compared to time out of treatment, retention on OAT was associated with a reduced rate of injecting-related diseases (adjusted rate ratio[ARR]=0.92; 95%CI 0.87-0.97). The first four weeks of treatment was associated with an increased rate (ARR 1.53, 95%CI 1.38-1.70), which we believe is explained by referral pathways between hospital and community OAT services. The age-adjusted incidence rates of hospitalisations for any injecting-related disease increased from 34.8 (95% CI =30.2-40.0) per 1000 person-years in 2001 to 54.9 (95%CI=51.3-58.8) in 2017.

INTERPRETATION

Stable OAT is associated with reduced hospitalisations for injecting-related bacterial infections; however, OAT appears insufficient to prevent these harms as the rate of these infections is increasing in Australia.

Hospitalisation with injection-related infections: Validation of diagnostic codes to monitor admission trends at a tertiary care hospital in Melbourne, Australia

INTRODUCTION

Injection-related infections (IRI) cause morbidity and mortality in people who inject drugs. Hospital administrative datasets can be used to describe hospitalisation trends, but there are no validated algorithms to identify injecting drug use and IRIs. We aimed to validate International Classification of Diseases (ICD) codes to identify admissions with IRIs and use these codes to describe IRIs within our hospital.

METHODS

We developed a candidate set of ICD codes to identify current injecting drug use and IRI and extracted admissions satisfying both criteria. We then used manual chart review data from 1 January 2017 to 30 April 2019 to evaluate the performance of these codes and refine our algorithm by selecting codes with a high-positive predictive value (PPV). We used the refined algorithm to describe trends and outcomes of people who inject drugs with an IRI at Alfred Hospital, Melbourne from 2008 to 2020.

RESULTS

Current injecting drug use was best predicted by opioid-related disorders (F11), 80% (95% confidence interval [CI] 74-85%), and other stimulant-related disorders (F15), 82% (95% CI 70-90%). All PPVs were ≥67% to identify specific IRIs, and ≥84% for identifying any IRI. Using these codes over 12 years, IRIs increased from 138 to 249 per 100 000 admissions, and skin and soft tissues infections (SSTI) were the most common (797/1751, 46%).

DISCUSSION AND CONCLUSION

Validated ICD-based algorithms can inform passive surveillance systems. Strategies to reduce hospitalisation with IRIs should be supported by early intervention and prevention, particularly for SSTIs which may represent delayed access to care.

Prevalence and factors associated with chronic venous insufficiency, leg ulceration and deep-vein thrombosis among people who inject drugs in London, UK

INTRODUCTION

People who inject drugs (PWID) are vulnerable to a range of harms, including vascular conditions such as chronic venous insufficiency (CVI), leg ulcers and deep vein thrombosis (DVT). The extent of vascular conditions has rarely been studied, despite contributing to considerable illness and disability among PWID. We assess the prevalence and associations of vascular conditions in PWID in London, UK.

METHODS

Survey data from the community-recruited Care and Prevent Study of PWID in London were analysed. Participants were asked about CVI and leg ulcers using pictorial questions, and if they had ever been diagnosed with DVT. Associations between vascular conditions and demographic/drug-use information were explored using univariate and multivariable logistic regression.

RESULTS

Among participants (n = 455), the prevalence of CVI, leg ulcers and DVT was 13% (n = 57), 10% (n = 46) and 23% (n = 105), respectively. CVI and DVT were positively associated with injecting into the groin, while injecting into the leg was positively associated with leg ulcers and DVT. CVI was also associated with not cleaning injection sites and diagnosed hepatitis C virus, and DVT with hepatitis C virus.

DISCUSSION AND CONCLUSION

The prevalence of vascular problems among PWID in London is very high in comparison to the general population. These conditions are primarily associated with injection into the femoral vein. Use of these injection sites indicates peripheral venous access problems. There is a need to reinvigorate safe injection information provision in harm reduction services, with attention to reducing risk practices associated with venous damage and transitions to femoral injection.

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

INTRODUCTION

Injecting-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 ANALYSIS

This 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 DISSEMINATION

As 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 NUMBER

CRD42021231411.

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.

The Clinical and Financial Burden of Spinal Infections in People who Inject Drugs

BACKGROUND

People who inject drugs (PWID) are known to be at increased risk of infectious diseases including bacterial and blood-borne viral infections. However, there is limited literature surrounding the burden of spinal infections as a complication of injecting drug use (IDU).

AIMS

To quantify the clinical and financial burden of IDU-related spinal infections.

METHODS

Retrospective chart review of adult PWID with spinal infections requiring hospital admission to a tertiary health service in Melbourne, Australia between 2011 and 2019.

RESULTS

Fifty-seven PWID with 63 episodes of spinal infections were identified with a median hospital stay of 47 days (IQR 16, range 4-243). One-third of episodes required neurosurgical intervention and 11 episodes (17%) required intensive care unit (ICU) admission (range 2-17 days). Staphylococcus aureus was the most common causative pathogen, present in three-quarters of all episodes (n = 47). The median duration of antibiotic regime was 59 days (IQR 42) and longer courses were associated with known bacteraemia (p = 0.048), polymicrobial infections (p = 0.001) and active IDU (p = 0.066). Predictors of surgery include neurological symptoms at presentation (RR 2.6; p = 0.010), inactive IDU status (RR 3.0; p = 0.002), a diagnosis of epidural abscess (RR 4.1; p = 0.001) and spinal abscess (RR ∞; p < 0.001). Completion of planned antimicrobial therapy was reported in 51 episodes (82%). Average expenditure per episode was AUD $61 577.

CONCLUSIONS

Spinal infections in PWID are an underreported serious medical complication of IDU. Though mortality is low, there is significant morbidity with prolonged admissions, large antimicrobial requirements and surgical interventions generating a substantial cost to the health system. This article is protected by copyright. All rights reserved.

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.

Profile and correlates of injecting-related injuries and diseases among people who inject drugs in Australia

INTRODUCTION

People who inject drugs (PWID) commonly experience harms related to their injecting, many of which are consequences of modifiable drug use practices. There is currently a gap in our understanding of how certain injecting-related injuries and diseases (IRID) cluster together, and socio-demographic and drug use characteristics associated with more complex clinical profiles.

METHOD

Surveys were conducted with 902 Australian PWID in 2019. Participants provided information regarding their drug use, and past month experience of the following IRID: artery injection, nerve damage, skin and soft tissue infection, thrombophlebitis, deep vein thrombosis, endocarditis, septic arthritis, osteomyelitis, and septicaemia. We performed a latent class analysis, grouping participants based on reported IRID and ran a class-weighted regression analysis to determine variables associated with class-membership.

RESULTS

One-third (34 %) of the sample reported any IRID. A 3-class model identified: 1) no IRID (73 %), moderate IRID (21 %), and 3) high IRID (6%) clusters. Re-using one`s own needles was associated with belonging to the high IRID versus moderate IRID class (ARRR = 2.38; 95 % CI = 1.04-5.48). Other factors, including daily injecting and past 6-month mental health problems were associated with belonging to moderate and high IRID classes versus no IRID class.

CONCLUSION

A meaningful proportion of PWID reported highly complex IRID presentations distinguished by the presence of thrombophlebitis and associated with greater re-use of needles. Increasing needle and syringe coverage remains critical in addressing the harms associated with injecting drug use and expanding the capacity of low-threshold services to address less severe presentations might aid in reducing IRID amongst PWID.

Prevalence and severity of abscesses and cellulitis, and their associations with other health outcomes, in a community-based study of people who inject drugs in London, UK

BACKGROUND

Skin and soft tissue infections (SSTI) are a common but preventable cause of morbidity and mortality among people who inject drugs (PWID). They can be severe, and hospitalisations of PWID with SSTI are rising. The most common SSTI presentations are abscesses and cellulitis.

METHODS

We used data from Care & Prevent, a cross-sectional community survey of PWID in London. We reported the lifetime prevalence of SSTI, severity of infections, key risk factors, and associated sequelae. Pictorial questions were used to assess SSTI severity.

RESULTS

We recruited 455 PWID. SSTI lifetime prevalence was high: 64% reported an abscess and/or cellulitis. Over one-third (37%) reported a severe infection, 137 (47%) reported hospitalisation. SSTIrisk factors were: aged 35+ years, injecting once or more times a day, subcutaneous or intra-muscular injections, and making four or more attempts to achieve an injection. Those who reported having other health conditions were at higher odds of having an abscess or cellulitis, with risk tending to increase with number of reported conditions. Half (46%) employed self-care for their worst SSTI, and 43% waited for ten or more days before seeking medical care or not seeking medical care at all.

CONCLUSIONS

Abscess and cellulitis are very common among PWID in London. We corroborate findings indicating SSTIs are associated with risks, e.g. venous access problems, as well as other co-morbid conditions: septicaemia, endocarditis, DVT, and kidney disease. These co-morbidities may impact SSTIs severity and outcomes. Delayed healthcare seeking potentially exacerbates infection severity, which in turn increases poorer health outcomes and complications.