Skin and Soft Tissue Infections in Persons Who Inject Drugs

The effect of Montreal's supervised consumption sites on injection-related infections among people who inject drugs: An interrupted time series

BACKGROUND

Between June and November 2017, four supervised consumption sites (SCS) began operating in Montreal, Quebec. Earlier studies on SCS focused on examining their effects on blood-borne viral infections and overdose mortality. Our objective was to examine the effect of Montreal's SCS on the incidence, health service use and outcomes of injection-related infections (IRI) in people who inject drugs.

METHODS

We used Quebec's provincial administrative health data to identify people who inject drugs in Montreal and calculated the incidence of IRI in this population between December 2014 and December 2019. We conducted a retrospective, population-based interrupted time series to estimate the effect of Montreal's four SCS on the monthly incidence rates of IRI-related hospitalizations, emergency department (ED) visits, physician visits, and mortality. We also examined the effects of SCS on average length of IRI-related hospitalizations and incidence of hospitalizations involving surgery.

RESULTS

The average age of Montreal's people who inject drugs was 41.84 years, and 66.41% were male. After the implementation of SCS, there was a positive level change in the incidence of hospitalizations (0.97; 95% confidence interval [CI]: 0.26, 1.68) for IRI. There was also a significant post-intervention decline in hospitalization trends (-0.05; 95% CI: -0.08, -0.02), with modest trend changes in ED visits (-0.02; 95% CI: -0.05, 0.02). However, post-intervention changes in level (0.72; 95% CI: -3.85, 5.29) and trend (0.06; 95% CI: -0.23, 0.34) for physician visits remained limited. SCS had no effect on the average length of hospitalizations, but there was a decreasing post-intervention trend in hospitalizations involving surgery (-0.03; 95% CI: -0.06, 0.00).

CONCLUSION

Following the opening of the SCS, there was a moderate decline in the rate of hospitalizations to treat IRI, but the impact of the sites on the rate of physician visits remained limited. These findings suggest that SCS may mitigate the incidence of more serious and complicated IRI over time.

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.

Necrotic Upper-Extremity Infections in People Who Inject Drugs: A Case Series

PURPOSE

Our institution has noted an increase in severe upper-extremity infections within the last 2 years. These patients have required transhumeral amputation. This case series demonstrates some of the catastrophic outcomes of these infections in people who inject drugs, which has been postulated to be related to the addition of xylazine to injectable drugs in our community.

METHODS

The study included patients presenting with severe upper-extremity infections resulting from intravenous drug use and requiring upper-extremity amputation between January 1, 2020 and September 30, 2022 at a single, urban, level 1 trauma center. Patient information and clinical images were collected through retrospective chart review.

RESULTS

Eight patients were identified at our institution with extensive necrosis of the skin and soft tissues in the forearm and hand, resulting in exposure of the radius and ulna. None of these patients had viable motor function in the hand and presented with a lack of sensation. All underwent transhumeral amputations, including bilaterally in one case.

CONCLUSIONS

The patients in this case series self-reported injection of tranquilizer-containing drugs, and xylazine has been reported to be present in 91% of heroin and fentanyl samples in our community. Although more studies are needed to confirm that xylazine is the definitive cause of the extensive tissue necrosis seen in these patients, we have found the severity of these infections to be noteworthy, given the likely expansion of xylazine to drug samples beyond our region.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

The Intersection of Substance Use Disorders and Infectious Diseases in the Emergency Department

Substance use disorders (SUDs) intersect clinically with many infectious diseases, leading to significant morbidity and mortality if either condition is inadequately treated. In this article, we will describe commonly seen SUDs in the emergency department (ED) as well as their associated infectious diseases, discuss social drivers of patient outcomes, and introduce novel ED-based interventions for co-occurring conditions. Clinicians should come away from this article with prescriptions for both antimicrobial medications and pharmacotherapy for SUDs, as well as an appreciation for social barriers, to care for these patients.

The burden of skin and soft tissue, bone and joint infections in an Australian cohort of people who inject drugs

INTRODUCTION

There are currently limited data regarding the clinical and economic significance of skin and soft tissue infections (SSTI) and bone and joint infections in Australian people who inject drugs (PWID).

METHODS

Retrospective cohort study in adult PWID admitted to Monash Health, a large heath care network with six hospitals in Victoria, Australia. Inpatients were identified using administrative datasets and International Classification of Disease (ICD-10) coding for specific infection-related conditions. Cost analysis was based on mean ward, intensive care and hospital-in-the-home (HITH) lengths of stay. Spinal infections and endocarditis were excluded as part of previous studies.

RESULTS

A total of 185 PWID (61 female, 124 male, median age 37) meeting the study criteria were admitted to Monash Health between January 2010 and January 2021. Admitting diagnoses included 78 skin abscesses, 80 cellulitis, 17 septic arthritis, 4 osteomyelitis, 3 thrombophlebitis and 1 each of necrotising fasciitis, vasculitis and myositis. Pain (87.5%) and swelling (75.1%) were the most common presenting complaints. Opioids (67.4%) and methamphetamine (37.5%) were the most common primary drugs injected. Almost half (46.5%) of patients had concurrent active hepatitis C (HCV) infection on admission. Hepatitis B (HBV) and Human Immunodeficiency Virus (HIV) were uncommon. The most significant causative organism was methicillin-susceptible Staphylococcus aureus (24.9%). In 40.0% (74/185) no organism was identified. Patients required a median acute hospital stay of 5 days (2-51 days). There were 15 patients admitted to the intensive care unit (ICU) with median duration 2 days. PICC line insertion for antibiotics was required in 16.8% of patients, while 51.4% required surgical intervention. Median duration of both oral and IV antibiotic therapy was 11 days. Almost half (48.6%) of patients were enrolled in an opioid maintenance program on discharge. Average estimated expenditure was AUD $16, 528 per admission.

CONCLUSION

Skin and soft tissue and joint infections are a major cause of morbidity for PWID. Admission to hospital provides opportunistic involvement of addiction specialty services.

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.

Health risks associated with smoking versus injecting fentanyl among people who use drugs in California

BACKGROUND

Given the attention, funding, and services that seek to reduce overdose mortality from fentanyl, it is important to understand whether a potential solution is for more people to switch from injecting to smoking fentanyl. As such, we set out to conduct a study to compare health and healthcare utilization outcomes associated with different modes of illicit fentanyl administration.

METHODS

From January to February 2023, we recruited people who use drugs from 34 syringe services programs across California, USA (N=999) and surveyed their substance use, health outcomes, and healthcare utilization. We compared health risks among people who injected fentanyl (78% of whom also smoked) to people who solely smoked fentanyl (n=563).

RESULTS

Of the 563 participants, forty-one percent injected fentanyl and 59% only smoked fentanyl. People who injected fentanyl were 40% more likely to have experienced a non-fatal overdose in the past 3 months (27% vs. 19%; aRR=1.40; 95% CI=1.03, 1.93) and 253% more likely to have had a skin and soft tissue infection in the past 3 months (39% vs. 15%; aRR=2.53; 95% CI=1.74, 3.67), compared to people who only smoked fentanyl. The average number of nights spent in the hospital was higher among people who injected fentanyl (average 1.2 nights vs. 0.7 nights; aIRR=1.78; 95% CI=1.02, 3.09; p=0.04).There were non-significant associations between mode of fentanyl administration and number of emergency department visits and probability of hospitalization.

CONCLUSIONS

Findings suggested that people who injected fentanyl were at higher risk for overdose and skin and soft tissue infections than people who only smoked fentanyl. Distribution of safe smoking supplies may facilitate transitions from injecting to smoking fentanyl, thereby reducing health risks associated with fentanyl use.

Reducing the harms of xylazine: clinical approaches, research deficits, and public health context

OBJECTIVES

Xylazine has emerged as a consistent part of the unregulated drug supply in recent months. We discuss major domains of xylazine's harm, current knowledge deficits, clinical and harm reduction strategies for minimizing harm, and xylazine's public health and policy context. As an interdisciplinary team from across the USA, we have pooled our knowledge to provide an overview of xylazine's current and emerging contexts.

METHODS

To inform this essay, the pertinent literature was reviewed, clinical knowledge and protocols were shared by multiple clinicians with direct expertise, and policy and public health context were added by expert authors.

RESULTS

We describe xylazine's major harm domains-acute poisoning, extended sedation, and wounds, along with anemia and hyperglycemia, which have been reported anecdotally but lack as clear of a connection to xylazine. Current successful practices for xylazine wound care are detailed. Understanding xylazine's epidemiology will also require greater investment in drug checking and surveillance. Finally, approaches to community-based wound care are discussed, along with an orientation to the larger policy and public health context.

CONCLUSIONS

Addressing the harms of xylazine requires interdisciplinary participation, investment in community-based harm reduction strategies, and improved drug supply surveillance. The relatively unique context of xylazine demands buy-in from public health professionals, harm reduction professionals, clinicians, basic science researchers, policymakers and more.

Community-acquired skin and soft-tissue infections in people who inject drugs

PURPOSE OF REVIEW

The aim of this review is to discuss the latest evidence of the epidemiology, microbiology, risk factors, diagnosis and management of community-acquired skin and soft tissue infections (SSTIs) in people who inject drug (PWID).

RECENT FINDINGS

SSTIs are common complications in PWID and a major cause of morbidity and mortality. Infections can range from uncomplicated cellulitis, to abscesses, deep tissue necrosis and necrotizing fasciitis. They are predominantly caused by Gram-positive pathogens in particular Staphylococcus aureus and Streptococcus species; however, toxin-producing organisms such as Clostridium botulism or Clostridium tetani should be considered. The pathogenesis of SSTI in the setting of intravenous drug use (IDU) is different from non-IDU related SSTI, and management often requires surgical interventions in addition to adjunctive antibiotics. Harm reduction strategies and education about safe practices should be implemented to prevent morbidity and mortality as well as healthcare burden of SSTI in PWID.

SUMMARY

Prompt diagnosis and proper medical and surgical management of SSTI will improve outcomes in PWID.

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.

Extensive direct spreading of "groin hit"-related soft tissue infections: a report of three cases

We present fatal extensive soft tissue infections, a consequence of groin heroin injection, in three subjects, who were 27, 34, and 39 years old and had a history of over 10-, 15-, and 5-years of heroin injection (cases 1, 2, and 3, respectively). In all cases, the first symptoms of the infection appeared at least a week prior, with rapid deterioration on the last day. The hallmark was a disproportion between external and internal findings in the affected thighs. The latter presented as extensively spread suppurative inflammation with soft tissue necrosis. In case 1, subtle skin erythema was present in the left groin, with a wound suggestive of a recent abscess incision and injection-related scarring. However, dissection revealed that inguinal regions and deep soft tissue (including the muscle sheets) of the left thigh, gluteal region, and lower third of the anterior abdominal wall were inflamed with pus, alongside fibrinopurulent peritonitis. Case 2 had pronounced erythema and swelling of the thigh and knee. Diffuse suppuration was observed upon dissection in the inguinal regions, which extended into the iliopsoas muscles, with soft tissue and muscle necrosis. In the abdominal cavity, we detected 150 mL of serofibrinous exudate. Only case 3 had a prominent, 4 × 3.5-cm necrotic skin defect through which pus spontaneously drained. In contrast to the other two, although extensive pus collection within predominantly necrotic thigh's soft tissue was present, the inflammation did not expand above the inguinal ligament, and peritonitis was not observed. Toxicology analysis excluded acute heroin intoxications.

CT utilization in evaluation of skin and soft tissue extremity infections in the ED: Retrospective cohort study

OBJECTIVE

Skin and soft tissue infections (SSTI) are commonly diagnosed in the emergency department (ED). While most SSTI are diagnosed with patient history and physical exam alone, ED clinicians may order CT imaging when they suspect more serious or complicated infections. Patients who inject drugs are thought to be at higher risk for complications from SSTI and may undergo CT imaging more frequently. The objective of this study is to characterize CT utilization when evaluating for SSTI in ED patients particularly in patients with intravenous drug use (IVDU), the frequency of significant and actionable findings from CT imaging, and its impact on subsequent management and ED operations.

METHODS

We performed a retrospective analysis of encounters involving a diagnosis of SSTI in seven EDs across an integrated health system between October 2019 and October 2021. Descriptive statistics were used to assess overall trends, compare CT utilization frequencies, actionable imaging findings, and surgical intervention between patients who inject drugs and those who do not. Multivariable logistic regression was used to analyze patient factors associated with higher likelihood of CT imaging.

RESULTS

There were 4833 ED encounters with an ICD-10 diagnosis of SSTI during the study period, of which 6% involved a documented history of IVDU and 30% resulted in admission. 7% (315/4833) of patients received CT imaging, and 22% (70/315) of CTs demonstrated evidence of possible deep space or necrotizing infections. Patients with history of IVDU were more likely than patients without IVDU to receive a CT scan (18% vs 6%), have a CT scan with findings suspicious for deep-space or necrotizing infection (4% vs 1%), and undergo surgical drainage in the operating room within 48 h of arrival (5% vs 2%). Male sex, abnormal vital signs, and history of IVDU were each associated with higher likelihood of CT utilization. Encounters involving CT scans had longer median times to ED disposition than those without CT scans, regardless of whether these encounters resulted in admission (9.0 vs 5.5 h), ED observation (5.5 vs 4.1 h), or discharge (6.8 vs 2.9 h).

DISCUSSION

ED clinicians ordered CT scans in 7% of encounters when evaluating for SSTI, most frequently in patients with abnormal vital signs or a history of IV drug use. Patients with a history of IVDU had higher rates of CT findings suspicious for deep space infections or necrotizing infections and higher rates of incision and drainage procedures in the OR. While CT scans significantly extended time spent in the ED for patients, this appeared justified by the high rate of actionable findings found on imaging, particularly for patients with a history of IVDU.

Prevalence and factors associated with hospitalisation for bacterial skin infections among people who inject drugs: The ETHOS Engage Study

BACKGROUND

Injecting-related skin and soft tissue infections (SSTIs) are a preventable cause of inpatient hospitalisation among people who inject drugs (PWID). This study aimed to determine the prevalence of hospitalisation for SSTIs among PWID, and identify similarities and differences in factors associated with hospitalisation for SSTIs versus non-bacterial harms related to injecting drug use.

METHODS

We performed cross-sectional analyses of baseline data from an observational cohort study of PWID attending drug treatment clinics and needle and syringe programs in Australia. Logistic regression models were used to identify factors associated with self-reported hospitalisation for (1) SSTIs (abscess and/or cellulitis), and (2) non-bacterial harms related to injecting drug use (e.g., non-fatal overdose; hereafter referred to as non-bacterial harms), both together and separately.

RESULTS

1851 participants who injected drugs in the previous six months were enrolled (67% male; 85% injected in the past month; 42% receiving opioid agonist treatment [OAT]). In the previous year, 40% (n = 737) had been hospitalised for drug-related causes: 20% (n = 377) and 29% (n = 528) of participants were admitted to hospital for an SSTI and non-bacterial harm, respectively. Participants who were female (adjusted odds ratio [aOR]: 1.53, 95% CI: 1.19-1.97) or homeless (aOR: 1.59, 95% CI: 1.16-2.19) were more likely to be hospitalised for an SSTI, but not a non-bacterial harm. Both types of hospitalisation were more likely among people recently released from prison.

CONCLUSIONS

Hospitalisation for SSTIs is common among PWID. Community-based interventions to prevent SSTIs and subsequent hospitalisation among PWID will require targeting of at-risk groups, including women, people experiencing homelessness, and incarcerated people upon prison release.

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.

Fulminant Necrotizing Pyomyositis Tropicans

Pyomyositis tropicans is a purulent invasive infection of the striated muscle tissues, usually caused by Gram-positive bacteria Staphylococcus aureus and Streptococcus in immunocompromised patients. We hereby report a case of fulminant necrotizing pyomyositis that occurred in a 16-year-old immunocompetent patient, and it is the first one of its kind to the best of our knowledge. The patient underwent imaging which suggested extensive intramuscular abdominal wall abscess formation, for which the patient underwent multiple surgical debridements of the lateral thoracic wall. Subsequent cultures grew Escherichia coli as the causative organism. Postoperatively, the patient went into catastrophic, irreversible septic shock ending in an eventual fatality.

Participants of a mail delivery syringe services program are underserved by other safe sources for sterile injection supplies

BACKGROUND

In the United States, accessing sterile injection supplies remains challenging for many people who inject drugs (PWID). Although women are less likely to inject drugs than men, women who do inject are disproportionately affected by IDU-related complications. Needle Exchange Technology (NEXT), the first formal online accessed mail delivery syringe services program (SSP) in the US, may overcome access barriers. We evaluated whether NEXT was reaching women participants and people without access to other safe sources of sterile injection supplies.

METHODS

This cross-sectional study examined NEXT participants who enrolled in the mail-delivery SSP from February 2018 through March 2021. All NEXT participants completed an online questionnaire during enrollment, which included sociodemographic and clinical characteristics and injection-related risk factors (including prior sources of sterile injection supplies). Multivariable logistic regression (MVR) was used to examine associations between gender and prior use of safe sources of injection supplies (i.e., SSPs or pharmacies).

RESULTS

1,032 participants received injection supplies. Median age was 34 and participants were mostly cis-gendered women (55%) and white (93%). 34% reported infection with HCV; women were more likely to report HCV infection than men (38% vs 28%; p < 0.01). 68% of participants acquired injection supplies from less safe sources. Few participants exclusively used safe sources for injection supplies (26%). In adjusted MVR analysis, women participants had significantly lower odds than men of having exclusively used safe sources for injection supplies (adjusted OR 0.71, 95% CI 0.52, 0.98).

CONCLUSION

Our findings suggest that NEXT services are utilized by women and people without prior access to sterile injection supplies. Women participants were less likely than men to have exclusively used safe sources for sterile injection supplies. Future research should explore women's preference for mail-delivery over in-person SSPs and determine whether online accessed mail delivery services can reach other underserved populations of PWID.

Health-Related Quality of Life as Measured by the 36-Item Short Form Survey Among Adults With Acute Bacterial Skin and Skin Structure Infections who Received Either Omadacycline or Linezolid in a Phase 3 Double-Blind, Double-Dummy Clinical Trial

This analysis of data from a Phase 3 study of adults with acute bacterial skin and skin structure infections showed that successful oral treatment with omadacycline (n = 368) or linezolid (n = 367) was associated with improvement in health-related quality of life.