Epidemiologic and clinical characteristics of infective endocarditis: a single-center retrospective study in the Bronx, New York.

OBJECTIVE: There is paucity of data on the epidemiological, microbiological, and clinical characteristics of patients admitted with infective endocarditis (IE) in the Bronx, New York. PATIENT AND METHODS: We conducted a retrospective study at Jacobi Medical Center, a tertiary care hospital in the Bronx. All adult patients who were hospitalized with a primary diagnosis of new-onset IE between January 1st, 2010 and September 30th, 2020 were included. The primary outcome was in-hospital mortality. A logistic regression model was used to identify baseline variables associated with in-hospital mortality. RESULTS: 182 patients were included in this analysis (female sex: 38.5%, median age: 54 years). 46 patients (25.3%) reported intravenous drug use. 153 patients (84.1%) had positive blood cultures. Staphylococcus aureus (S. aureus) was the most common isolated pathogen (45.1% of monomicrobial IE). Nearly half of the cases secondary to S. aureus were methicillin resistant Staphylococcus aureus (MRSA) (34/69). 164 patients (90.1%) were diagnosed with native valve IE. The mitral valve was involved in 32.4% of patients followed by the aortic valve (19.8%). The in-hospital mortality was 18.1%. The mortality was higher in the cohort 2010-2015 compared to the cohort 2016-2020 (22.1% vs 14.6%). Increasing age, MRSA IE, and active malignancy were the only variables found to have significant association with in-hospital death. CONCLUSION: S. aureus was the most common causative agent and MRSA accounted for about half of the S. aureus IE cases. The incidence of IE in patients with intravenous drug use increased over time, while the median age decreased. The in-hospital death rate was higher in 2010-2015 compared to 2016-2020.

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.

Isolated cerebral mucormycosis associated with intravenous drug use.

We present an uncommon case of isolated basal ganglia mucormycosis in a patient without any known cause of immunosuppression, but with a history of drug injection. The patient presented a good clinical and radiological response to antifungal treatment without aggressive surgical debridement (liposomal amphotericin B combined with isavuconazole for 4 weeks followed by isavuconazole as maintenance therapy for 10 months).

Navigating environmental constraints to injection preparation: the use of saliva and other alternatives to sterile water among unstably housed PWID in London.

BACKGROUND: The United Kingdom is experiencing an increase in drug-related deaths and serious bacterial infections among its most vulnerable citizens. Cuts to essential services, coupled with a growing homeless population, create a challenging environment to tackle this public health crisis. In this paper, we highlight an underexplored environmental constraint faced by people living and injecting drugs on the streets. Access to water for injection is restricted in the UK, due to legislative and financial barriers. Austerity measures, such as public toilet closures, further restrict the ability of people made homeless to access clean water and protect themselves from health harms. METHODS: We generated questionnaire (n = 455) and in-depth qualitative interview (n = 32) data with people who inject drugs in London for the Care and Prevent study. Participants provided detail on their life history; drug use, injecting and living environments; health conditions and care seeking practices. FINDINGS: A high proportion of the survey sample reported lifetime history of street homelessness (78%), bacterial infections (65%) and related hospitalisation (30%). Qualitative accounts highlight unsafe, potentially dangerous, injection practices in semi-public spaces. Multiple constraints to sourcing sterile water for injection preparation were reported. Alternatives to sterile water included puddle water, toilet cistern water, whisky, cola soda and saliva. Participants who injected heroin and crack cocaine together unanimously reported adding water at two stages during injection preparation: first, adding water as a vehicle for heroin (which was then heated); second, adding cold water to the heroin mixture prior to adding the crack cocaine. This new finding of a stage addition of solvent may represent an additional risk of infection. CONCLUSION: Currently, harm reduction equipment and resources for safe injecting are not meeting the needs of people who inject drugs who are street homeless or unstably housed. Preparation of injections with non-sterile water sources could precipitate bacterial and fungal infections, particularly when used without the application of heat. It is crucial that water for injection, also skin cleaning, is made available for the unstably housed and that harm reduction messaging is tailored to speak to the everyday realities of people who prepare and inject drugs in public spaces.

Diagnostic Performance of CT-Guided Bone Biopsies in Patients with Suspected Osteomyelitis of the Appendicular and Axial Skeleton with a Focus on Clinical and Technical Factors Associated with Positive Microbiology Culture Results.

PURPOSE: To assess diagnostic performance of CT-guided percutaneous needle bone biopsy (CTNBB) in patients with suspected osteomyelitis and analyze whether certain clinical or technical factors were associated with positive microbiology results. MATERIALS AND METHODS: All CTNBBs performed in a single center for suspected osteomyelitis of the appendicular and axial skeleton during 2003-2018 were retrospectively reviewed. Specific inclusion criteria were clinical and radiologic suspicion of osteomyelitis. Standard of reference was defined using outcome of surgical histopathology and microbiology culture and clinical and imaging follow-up. Technical and clinical data (needle size, comorbidities, clinical factors, laboratory values, blood cultures) were collected. Logistic regression was performed to assess associations between technical and clinical data and microbiology biopsy outcome. RESULTS: A total of 142 CTNBBs were included (46.5% female patients; age ± SD 46.10 y ± 22.8), 72 (50.7%) from the appendicular skeleton and 70 (49.3%) from the axial skeleton. CTNBB showed a sensitivity of 42.5% (95% confidence interval [CI], 32.0%-53.6%) in isolating the causative pathogen. A higher rate of positive microbiology results was found in patients with intravenous drug use (odds ratio [OR] = 5.15; 95% CI, 1.2-21.0; P = .022) and elevated white blood cell count ≥ 10 × 109/L (OR = 3.9; 95% CI, 1.62-9.53; P = .002). Fever (≥ 38°C) was another clinical factor associated with positive microbiology results (OR = 3.6; 95% CI, 1.3-9.6; P = .011). CONCLUSIONS: CTNBB had a low sensitivity of 42.5% for isolating the causative pathogen. Rate of positive microbiology samples was significantly higher in patients with IV drug use, elevated white blood cell count, and fever.

Elevated troponin level as a predictor of inpatient mortality in patients with infective endocarditis in the Southeast United States.

BACKGROUND: Despite recent improvement in management, infective endocarditis (IE) continues to be associated with considerable risk of morbidity and mortality. Early identification of predictors of inpatient mortality is key in improving patient outcomes in IE. The aim of our study was to evaluate the role of serum troponin levels measurements as a marker of increased mortality. METHODS: A case-control study included adult patients with IE admitted to a tertiary care hospital in east Tennessee between December 2012 and July 2017. Cases were defined as patients with definitive IE who died in-hospital; controls were patients who did not die in hospital. First patient admission was included only. Data collected included the patients' demographic and baseline clinical information, microbiological data, injection drug use status, elevated serum troponins levels. RESULTS: Two hundred eighty three patients with definitive IE were included; median (IQR) age was 41 (30-57) years, and 153 (54%) patients were men. One-hundred sixty-four (58%) were injection drug users. The most frequent IE type was: 167 (59%) right-sided, 86 (30%) left-sided, 24 (9%) both left and right-sided, and 10 (4%) device related. The most commonly isolated organism was Staphylococcus aureus (n = 141), and 64% were methicillin-resistant. Two-hundred twelve (75%) patients had a troponin level obtained, and 57 (27%) had an elevated troponin value. Thirty-six (13%) patients died in-hospital; in-hospital mortality was associated elevated troponin values (adjusted odds ratio [adjOR], 7.3; 95%CI, 3.3-15.9), and methicillin-resistant S. aureus IE (adjOR 2.6; 95%CI, 1.2-5.8). Forty-four (16%) patients received IE valve surgery, and none of these patients died in the hospital. CONCLUSION: Inpatient mortality was higher in patients with IE and elevated cardiac troponin levels compared to patients with normal levels.

Infective Endocarditis in the Intravenous Drug Use Population at a Tertiary Hospital in Melbourne, Australia.

BACKGROUND: Infective endocarditis has been associated with underlying cardiac pathology and streptococci infections. Intravenous drug use (IVDU) is increasingly implicated as a contributing factor, resulting in a shift to a younger patient demographic, tricuspid valve involvement, severe staphylococcal infection, and unique management challenges. The objective of this study was to describe the clinical features, management and outcomes of patients with IVDU-associated infective endocarditis in the Australian context. METHODS: A retrospective review of all episodes of IVDU-associated infective endocarditis at a tertiary hospital in Melbourne, Australia, from 2008 to 2015, was conducted. Included cases met Duke Criteria for 'definite' or 'possible' infective endocarditis, and had a history of IVDU within 3 months of presentation. Demographic data, substance use history, clinical features, surgical intervention, follow-up, and mortality data was collected. We explored factors associated with surgical intervention, recurrence and mortality. RESULTS: Fifty-five (55) episodes of IVDU-associated infective endocarditis were identified in 46 patients; the median age was 40 years and 58% were male. The tricuspid valve was most commonly affected (38%), and left heart pathology was documented in 53% of cases. Methicillin-sensitive Staphylococcus aureus was the most common pathogen (67%). Thirty-six (36%) per cent of patients underwent surgical intervention, and all patients received antibiotics as a component of treatment, with a median duration of 42 days (IQR 21, 42 days). Heart failure and a vegetation larger than 1 cm were significantly associated with surgical intervention. Total mortality was 14.5%; surgical mortality was 10%. Opioid replacement therapy and the absence of psychiatric co-morbidities were protective factors for surgical intervention and disease recurrence. CONCLUSIONS: In contrast to common perception, left-sided endocarditis was more common than tricuspid valve endocarditis. Left heart pathology is typically a more severe clinical entity, however, our study determined mortality rates remained similar when compared to right heart pathology. Further research is required to assess rates of left sided disease in the IVDU population, and elucidate the relationship between IVDU and left heart pathology.

Associations between echocardiographic manifestations and bacterial species in patients with infective endocarditis: a cohort study.

BACKGROUND: The diagnosis of infective endocarditis (IE) is based on microbiological analyses and diagnostic imaging of cardiac manifestations. Echocardiography (ECHO) is preferred for visualization of IE-induced cardiac manifestations. We investigated associations between bacterial infections and IE manifestations diagnosed by ECHO. METHODS: In this cohort study, data from patients aged 18 years or above, with definite IE admitted at the Karolinska University Hospital between 2008 and 2017 were obtained from Swedish National Registry of Endocarditis. Bacteria registered as pathogen were primarily selected from positive blood culture and for patients with negative blood culture, bacteria found in culture or PCR from postoperative material was registered as pathogen. Patients with negative results from culture or PCR, and patients who did not undergo ECHO during hospital stay, were excluded. IE manifestations diagnosed by ECHO were obtained from the registry. Chi-squared test and two-sided Fisher's exact test was used for comparisons between categorical variables, and student's t test was used for continuous numerical variables. Multivariable analyses were performed using logistic regression. Secular trend analyses were performed using linear regression. Associations and the strength between the variables were estimated using odds ratios (ORs) with 95% confidence intervals (CIs). P < 0.05 was considered significant. RESULTS: The most common bacteria were Staphylococcus aureus (n = 239, 49%) and viridans group streptococci (n = 102, 21%). The most common manifestations were vegetation in the mitral (n = 195, 40%), aortic (n = 190, 39%), and tricuspid valves (n = 108, 22%). Associations were seen between aortic valve vegetations and Enterococcus faecalis among patients with native aortic valves, between mitral valve vegetations and streptococci of group B or viridans group, between tricuspid valve vegetations and S. aureus among patients with intravenous drug abuse, and between perivalvular abscesses as well as cardiovascular implantable electronic device (CIED)-associated IE and coagulase negative staphylococci (all P < 0.05). CONCLUSIONS: Associations were found between certain bacterial species and specific ECHO manifestations. Our study contributes to a better understanding of IE manifestations and their underlying bacterial etiology, which pathogens can cause severe infections and might require close follow-up and surgical treatment.

Compliance to antibiotic guidelines leads to more appropriate use of antibiotics in skin and soft tissue infections in injecting drug users.

Background: Knowledge about the treatment of skin and soft tissue infections in injecting drug users in countries with a low prevalence of antibiotic resistance is limited. We investigated bacterial antibiotic resistance and treatment of skin and soft tissue infections in Norwegian drug users. Methods: We performed a two year clinical cross-sectional observational study in a Norwegian hospital. Data were collected retrospectively from hospital records. We examined bacteriological findings and antibiotic resistance, and evaluated compliance to treatment guidelines and appropriateness of empirical antibiotic therapy relative to results of cultures and susceptibility testing. Descriptive and univariate analyses were performed. Results: Hundred and thirty-five injecting drug users were admitted with skin and soft tissue infection in the study period. Cultures were obtained from 103 (77%) abscesses and eight (24%) erysipelas and cellulitis, with bacterial growth in 80 (78%) and five (63%), respectively. Streptococci and staphylococci were the most prevalent bacteria, but methicillin-resistant Staphylococcus aureus was found in only one patient. Compliance to hospital antibiotic guidelines was 70%. Ninety-one per cent of patients in the compliant and 79% in the non-compliant group were given effective empirical antibiotics (p = .334). In the non-compliant group, significantly more patients received broad-spectrum empirical antibiotics (p < .001). In 30 cases where adjustment of antibiotic therapy was possible according to susceptibility testing, this was performed in only 14 cases. Conclusions: Bacteria and resistance patterns did not differ significantly from the skin and soft tissue infections in the general population in Norway. Compliance to antibiotic guidelines led to significantly less use of broad-spectrum antibiotics and to good bacterial coverage. General guidelines for treatment should be applied to injecting drug users with skin and soft tissue infections.

Tricuspid Valve Infective Endocarditis Due to Klebsiella pneumoniae in Intravenous Drug User.

Infective endocarditis is a high morbidity-mortality condition despite advancements in supportive care and medical therapy. One of the strongest risk factors is intravenous drug use, which has high prevalence in the Hawai'i population. Klebsiella pneumoniae is a rare but aggressive pathogen causing infective endocarditis. There is no strong evidence to guide management. We present a rare case of isolated tricuspid valve infective endocarditis due to Klebsiella pneumoniae in an intravenous drug user causing septic pulmonary emboli and multiple abscesses. The patient was managed with combined 6-week ceftriaxone and 2-week gentamicin together with early tricuspid valve repair.

Tricuspid valve infective endocarditis complicated with multiple lung abscesses and thoracic empyema as different pathogens: a case report.

BACKGROUND: Only 4.1% of tricuspid valve IE cases require surgical intervention. The complication after tricuspid valve IE with lung abscess and empyema is rare. CASE PRESENTATION: We report the case of a 38-year-old male (an intravenous drug abuser) diagnosed with tricuspid valve IE who underwent tricuspid valve replacement. The case was complicated by multiple lung abscesses and thoracic empyema. The pathogens causing the lung abscesses and empyema were Acinetobacter baumannii complex and Candida albicans, which were different from those causing the endocarditis. After 4 weeks of antibiotic treatment, chest X-ray revealed bilateral clear lung markings with only mild blunting of the right costophrenic angle. CONCLUSION: The pathogen causing the lung abscess is not always compatible with that causing the endocarditis. Thoracoscopic incision of the abscess with 4 to 6 weeks of broad-spectrum antibiotic treatment is effective and safe.

MRSA Incidence and Antibiotic Trends in Urban Hand Infections: A 10-Year Longitudinal Study.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is the most reported pathogen in hand infections at urban medical centers throughout the country. Antibiotic sensitivity trends are not well known. The purposes of this study were to examine and determine the drug resistance trends for MRSA infections of the hand and to provide recommendations for empiric antibiotic treatment based on sensitivity profiles. Methods: A 10-year longitudinal, retrospective chart review was performed on all culture-positive hand infections encountered at a single urban medical center from 2005 to 2014. The proportions of all organisms were calculated for each year and collectively. MRSA infections were additionally subanalyzed for antibiotic sensitivity. Results: A total of 815 culture-positive hand infections were identified. Overall, MRSA grew on culture in 46% of cases. A trend toward decreasing annual MRSA incidence was noted over the 10-year study period. There was a steady increase in polymicrobial infections during the same time. Resistance to clindamycin increased steadily during the 10-year study, starting at 4% in 2008 but growing to 31% by 2014. Similarly, levofloxacin resistance consistently increased throughout the study, reaching its peak at 56% in 2014. Conclusions: The annual incidence of MRSA in hand infections has declined overall but remains the most common pathogen. There has been an alternative increase in the number of polymicrobial infections. MRSA resistance to clindamycin and levofloxacin consistently increased during the study period. Empiric antibiotic therapy for hand infections should not only avoid penicillin and other beta-lactams but should also consider avoiding clindamycin and levofloxacin for empiric treatment.

Seroprevalence of Bartonella spp., Coxiella burnetii, and Hantavirus among people who inject drugs in Rio de Janeiro, Brazil: a retrospective assessment of a biobank.

The increasing use of illicit drugs imposes a public health challenge worldwide. People who inject drugs (PWID) are more susceptible to health complications due to immunosuppression associated with drug use and non-hygienic self-administration of substances, contaminants, and liquids. PWID are subjected to increased risk of acquiring and transmitting different pathogens (frequently functioning as sentinel cases for (re)emerging pathogens), including those transmitted by arthropods and vertebrate reservoirs in unhealthy environments. A clear association between injection drug use and HIV, HBV, and HCV infections has been described; however, other infectious viral and bacterial agents have been seldomly assessed. In this study, we investigated the seroprevalence of Bartonella spp., Coxiella burnetii, and Hantavirus among 300 randomly selected PWIDs from Rio de Janeiro, as part of a multi-city cross-sectional study carried out in the 1990s. Point seroprevalences and respective 95% CIs are as follows: 9.3% for C. burnetii (95% CI: 6.0%-13.0%), 1.0% for Bartonella spp. (95% CI: 0.0%-3.0%), and 4.0% for Hantavirus (95% CI: 2.0%-7.0%). In addition to the blood-borne pathogens, the results of this study increase our knowledge on other transmissible infectious agents in PWID. The high seroprevalence of C. burnetii and Hantavirus found among PWID is intriguing and suggests the need to carry out prospective studies, including molecular analyses, to confirm these findings and allow a better understanding of the putative relevance of these zoonotic infectious agents among PWID.

Successful treatment of Enterococcus faecalis bacteremia with dalbavancin as an outpatient in an intravenous drug user.

This report describes the treatment of a 35-year-old male who presented to the emergency department with an empyema, and who had a long hospital course complicated by a catheter-related bloodstream infection and a history of intravenous drug use. Blood culture results confirmed Enterococcus faecalis. He was not a candidate for outpatient intravenous therapy and needed 14days of treatment, but was able to be discharged with a 3-day supply of oral levofloxacin to complete treatment for his empyema and 1 dose of dalbavancin at an outpatient infusion center to treat his bacteremia. Due to the unique properties of dalbavancin, off-label use in specific populations may help facilitate transitions of care. This report outlines the successful use of dalbavancin and removal of the central catheter in the treatment of E. faecalis bacteremia.

Injectional anthrax in human: A new face of the old disease.

Unusual human behavior leads to the emergence of new forms of infectious diseases and new routes of infection. In recent years, a new form of anthrax, called injectional anthrax, emerged and was related to 2 human anthrax outbreaks in Europe. The infection was caused by heroin contaminated with anthrax spores. The new form of anthrax differs from the earlier known "natural" forms of the disease in symptoms, length of the incubation period and recommended treatment. Despite medical treatment, the mortality rate in injectional anthrax is about 35%. This article presents an overview of the forms of anthrax infection in humans, with focus on injectional anthrax syndrome, as well as actual recommendations for treatment, including antibiotic therapy, surgery and possibilities of administering anthrax antitoxin. As a source of contamination of heroin have not been identified and new cases of injectional anthrax might occur again in any country in the future.

Spore forming bacteria infections and people who inject drugs: Implications for harm reduction.

BACKGROUND: There is no research on public health interventions that alert people who inject drugs (PWID) to clusters/outbreaks of severe bacterial infections. In Scotland, during the botulism cluster/outbreak of Dec 2014-July 2015 harm reduction (HR) messages detailed on a postcard (Botulism Postcard) were distributed to PWID between Feb-April 2015. We examined the impact of the Botulism Postcard on cluster/outbreak awareness, healthcare seeking and HR behaviours among PWID; and their views on such clusters/outbreaks. METHODS: The Botulism Postcard questionnaire survey was undertaken with 288 PWID recruited in Greater Glasgow and Clyde between May-August 2015. Multivariate logistic regression was undertaken. Between Oct 2015-January 2016 22 in-depth interviews were conducted with PWID in Glasgow and Edinburgh, these underwent thematic analysis. RESULTS: 38% (108/284) had never seen the postcard, 14% (40/284) had only seen it, 34% (98/284) read but not discussed it and 13% (38/284) had discussed it with service staff. Cluster/outbreak awareness was higher among those who had read (adjusted odds ratio (aOR) = 5.374, CI 2.394-11.349, p < 0.001) or discussed the postcard (aOR = 25.114, CI 3.188-190.550, p < 0.001); and symptom awareness was higher among those who had read (aOR = 2.664, CI 1.322-4.890, p < 0.001) or discussed the postcard (aOR = 6.707, CI 2.744 16.252, p < 0.001) than among those who had never seen it. The odds of introducing HR was higher among those who had discussed the postcard (AOR = 3.304 CI 1.425 7.660, p < 0.01) than those who had only read it. PWID learnt about clusters/outbreaks from several sources and despite concerns they continued to inject during such events. CONCLUSION: More widespread exposure to the Botulism Postcard during the outbreak/cluster was needed. The Botulism Postcard distributed to PWID may raise awareness of such events, the symptoms, and may encourage HR particularly when used as a tool by frontline staff to initiate discussion. Acknowledging that people continue to inject during clusters/outbreaks of such infections necessitates a pragmatic HR approach.

Cardiac tamponade secondary to purulent pericarditis diagnosed with the aid of emergency department ultrasound.

Purulent pericarditis is a rare but devastating disease process and even when treated, carries a poor prognosis. Cardiac tamponade is the most severe complication of purulent pericarditis and without acute surgical intervention, is often fatal. Diagnosis requires pericardiocentesis; however, early consideration of the disease and its complications in the emergency department (ED) can be life-saving. Here, we present a case of an intravenous drug user who presented with altered mental status and a rectal temperature of 105.4°. While in the ED, the patient acutely decompensated. The ED physician performed bedside cardiac ultrasound that a showed pericardial effusion and right ventricle diastolic collapse concerning for cardiac tamponade. The patient underwent urgent pericardiocentesis which revealed 300 ml of purulent fluid. Both blood and pericardial cultures grew methicillin-sensitive Staphylococcus aureus. Despite a complicated hospital course, with appropriate antibiotic coverage and surgical intervention, the patient was discharged in good neurologic condition. This rare case of purulent pericarditis underscores the utility of bedside ultrasound in the ED and the complicated nature of altered mental status in intravenous drug users.

Heroin-associated anthrax with minimal morbidity.

In 2010, during an outbreak of anthrax affecting people who inject drugs, a heroin user aged 37 years presented with soft tissue infection. He subsequently was found to have anthrax. We describe his management and the difficulty in distinguishing anthrax from non-anthrax lesions. His full recovery, despite an overall mortality of 30% for injectional anthrax, demonstrates that some heroin-related anthrax cases can be managed predominately with oral antibiotics and minimal surgical intervention.

Analysis of Anthrax Immune Globulin Intravenous with Antimicrobial Treatment in Injection Drug Users, Scotland, 2009-2010.

We studied anthrax immune globulin intravenous (AIG-IV) use from a 2009-2010 outbreak of Bacillus anthracis soft tissue infection in injection drug users in Scotland, UK, and we compared findings from 15 AIG-IV recipients with findings from 28 nonrecipients. Death rates did not differ significantly between recipients and nonrecipients (33% vs. 21%). However, whereas only 8 (27%) of 30 patients at low risk for death (admission sequential organ failure assessment score of 0-5) received AIG-IV, 7 (54%) of the 13 patients at high risk for death (sequential organ failure assessment score of 6-11) received treatment. AIG-IV recipients had surgery more often and, among survivors, had longer hospital stays than did nonrecipients. AIG-IV recipients were sicker than nonrecipients. This difference and the small number of higher risk patients confound assessment of AIG-IV effectiveness in this outbreak.

Development of a filter to prevent infections with spore-forming bacteria in injecting drug users.

BACKGROUND: In heroin injectors, there have been a number of outbreaks caused by spore-forming bacteria, causing serious infections such as anthrax or botulism. These are, most likely, caused by injecting contaminated heroin, and our aim was to develop a filter that efficiently removes these bacteria and is also likely to be acceptable for use by people who inject drugs (i.e. quick, simple and not spoil the hit). METHODS: A prototype filter was designed and different filter membranes were tested to assess the volume of liquid retained, filtration time and efficiency of the filter at removing bacterial spores. Binding of active ingredients of heroin to different types of membrane filters was determined using a highly sensitive analytical chemistry technique. RESULTS: Heroin samples that were tested contained up to 580 bacteria per gramme, with the majority being Bacillus spp., which are spore-forming soil bacteria. To remove these bacteria, a prototype filter was designed to fit insulin-type syringes, which are commonly used by people who inject drugs (PWIDs). Efficient filtration of heroin samples was achieved by combining a prefilter to remove particles and a 0.22 µm filter to remove bacterial spores. The most suitable membrane was polyethersulfone (PES). This membrane had the shortest filtration time while efficiently removing bacterial spores. No or negligible amounts of active ingredients in heroin were retained by the PES membrane. CONCLUSIONS: This study successfully produced a prototype filter designed to filter bacterial spores from heroin samples. Scaled up production could produce an effective harm reduction tool, especially during outbreaks such as occurred in Europe in 2009/10 and 2012.