Risk Scores and Machine Learning to Identify Patients With Acute Periprosthetic Joints Infections That Will Likely Fail Classical Irrigation and Debridement

The most preferred treatment for acute periprosthetic joint infection (PJI) is surgical debridement, antibiotics and retention of the implant (DAIR). The reported success of DAIR varies greatly and depends on a complex interplay of several host-related factors, duration of symptoms, the microorganism(s) causing the infection, its susceptibility to antibiotics and many others. Thus, there is a great clinical need to predict failure of the “classical” DAIR procedure so that this surgical option is offered to those most likely to succeed, but also to identify those patients who may benefit from more intensified antibiotic treatment regimens or new and innovative treatment strategies. In this review article, the current recommendations for DAIR will be discussed, a summary of independent risk factors for DAIR failure will be provided and the advantages and limitations of the clinical use of preoperative risk scores in early acute (post-surgical) and late acute (hematogenous) PJIs will be presented. In addition, the potential of implementing machine learning (artificial intelligence) in identifying patients who are at highest risk for failure of DAIR will be addressed. The ultimate goal is to maximally tailor and individualize treatment strategies and to avoid treatment generalization.

Debridement, Antibiotics, and Implant Retention Is a Viable Treatment Option for Early Periprosthetic Joint Infection Presenting More Than 4 Weeks After Index Arthroplasty

BACKGROUND

The success of debridement, antibiotics, and implant retention (DAIR) in early periprosthetic joint infection (PJI) largely depends on the presence of a mature biofilm. At what time point DAIR should be disrecommended is unknown. This multicenter study evaluated the outcome of DAIR in relation to the time after index arthroplasty.

METHODS

We retrospectively evaluated PJIs occurring within 90 days after surgery and treated with DAIR. Patients with bacteremia, arthroscopic debridements, and a follow-up <1 year were excluded. Treatment failure was defined as (1) any further surgical procedure related to infection; (2) PJI-related death; or (3) use of long-term suppressive antibiotics.

RESULTS

We included 769 patients. Treatment failure occurred in 294 patients (38%) and was similar between time intervals from index arthroplasty to DAIR: the failure rate for Week 1-2 was 42% (95/226), the rate for Week 3-4 was 38% (143/378), the rate for Week 5-6 was 29% (29/100), and the rate for Week 7-12 was 42% (27/65). An exchange of modular components was performed to a lesser extent in the early post-surgical course compared with the late course (41% vs 63%, respectively; P < .001). The causative microorganisms, comorbidities, and durations of symptoms were comparable between time intervals.

CONCLUSIONS

DAIR is a viable option in patients with early PJI presenting more than 4 weeks after index surgery, as long as DAIR is performed within at least 1 week after the onset of symptoms and modular components can be exchanged.

Development of a severity of disease score and classification model by machine learning for hospitalized COVID-19 patients

BACKGROUND

Efficient and early triage of hospitalized Covid-19 patients to detect those with higher risk of severe disease is essential for appropriate case management.

METHODS

We trained, validated, and externally tested a machine-learning model to early identify patients who will die or require mechanical ventilation during hospitalization from clinical and laboratory features obtained at admission. A development cohort with 918 Covid-19 patients was used for training and internal validation, and 352 patients from another hospital were used for external testing. Performance of the model was evaluated by calculating the area under the receiver-operating-characteristic curve (AUC), sensitivity and specificity.

RESULTS

A total of 363 of 918 (39.5%) and 128 of 352 (36.4%) Covid-19 patients from the development and external testing cohort, respectively, required mechanical ventilation or died during hospitalization. In the development cohort, the model obtained an AUC of 0.85 (95% confidence interval [CI], 0.82 to 0.87) for predicting severity of disease progression. Variables ranked according to their contribution to the model were the peripheral blood oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) ratio, age, estimated glomerular filtration rate, procalcitonin, C-reactive protein, updated Charlson comorbidity index and lymphocytes. In the external testing cohort, the model performed an AUC of 0.83 (95% CI, 0.81 to 0.85). This model is deployed in an open source calculator, in which Covid-19 patients at admission are individually stratified as being at high or non-high risk for severe disease progression.

CONCLUSIONS

This machine-learning model, applied at hospital admission, predicts risk of severe disease progression in Covid-19 patients.

Tocilizumab reduces the risk of ICU admission and mortality in patients with SARS-CoV-2 infection

Objectives

In some patients the immune response triggered by SARS-CoV-2 is unbalanced, presenting an acute respiratory distress syndrome which in many cases requires intensive care unit (ICU) admission. The limitation of ICU beds has been one of the major burdens in the management around the world; therefore, clinical strategies to avoid ICU admission are needed. We aimed to describe the influence of tocilizumab on the need of transfer to ICU or death in non-critically ill patients.

Material and methods

A retrospective study of 171 patients with SARS-CoV-2 infection that did not qualify as requiring transfer to ICU during the first 24h after admission to a conventional ward, were included. The criteria to receive tocilizumab was radiological impairment, oxygen demand or an increasing of inflammatory parameters, however, the ultimate decision was left to the attending physician judgement. The primary outcome was the need of ICU admission or death whichever came first.

Results

A total of 77 patients received tocilizumab and 94 did not. The tocilizumab group had less ICU admissions (10.3% vs. 27.6%, P=0.005) and need of invasive ventilation (0 vs 13.8%, P=0.001). In the multivariable analysis, tocilizumab remained as a protective variable (OR: 0.03, CI 95%: 0.007-0.1, P=0.0001) of ICU admission or death.

Conclusions

Tocilizumab in early stages of the inflammatory flare could reduce an important number of ICU admissions and mechanical ventilation. The mortality rate of 10.3% among patients receiving tocilizumab appears to be lower than other reports. This is a non-randomized study and the results should be interpreted with caution.

Severe acute kidney injury in critically ill COVID-19 patients

BACKGROUND

Acute kidney injury (AKI) is frequent in Coronavirus Infection Disease 2019 (COVID-19) patients. Factors associated with AKI in COVID-19 intensive care unit (ICU) patients and their outcomes have not been previously explored.

METHODS

Prospective observational study of COVID-19 patients admitted to the ICUs of the Hospital Clínic of Barcelona (Spain), from March 25th to April 21st, 2020, who developed AKI stage 2 or higher (AKIN classification). The primary goal was to describe the characteristics of moderate-severe AKI of COVID-19 patients in an ICU context. As a secondary goal, we aimed to find independent predictors of AKI progression, Renal Replacement Therapy (RRT) requirement and mortality among these patients.

RESULTS

During the study period, 52 out of 237 ICU patients, developed AKIN stage 2 or higher and were included in the study. A Sequential Organ Failure Assessment (SOFA) score at AKI diagnosis of 8 or higher was associated with RRT, OR 5.2, p 0.032. At the time of AKI diagnosis, patients had a worse liver profile and higher inflammation markers than at admission. Fifty per cent of the patients presented AKI progression from AKIN 2 to 3 and 28.85% required RRT. The use of corticosteroids in 69.2% of patients was associated with a reduced requirement of RRT, OR 0.13 (CI 95% 0.02-0.89), p 0.037. AKI was associated with high mortality (50%) and a longer hospital stay, median 35 vs 18 days (p 0.024).

CONCLUSIONS

The prevalence of moderate/severe AKI in COVID-19 patients admitted to the ICU is high and has a strong correlation with mortality and length of hospital stay.

Risk Factors for Mortality in Hematopoietic Stem Cell Transplantation Recipients with Bloodstream Infection: Points To Be Addressed by Future Guidelines

In recent years, important epidemiologic changes have been described in hematopoietic stem cell transplantation (HSCT) recipients with bloodstream infection (BSI), with increases in gram-negative bacilli and multidrug resistant (MDR) gram-negative bacilli. These changes have been linked to a worrisome increase in mortality. We aimed to define the risk factors for mortality of HSCT patients experiencing BSI. All episodes of BSI in patients with HSCT between 2008 and 2017 were prospectively collected. Multivariate analyses were performed. A total of 402 BSI episodes were documented in 293 patients who had undergone HSCT (75.4% allogenic, 32.3% autologous, 19.3% second HSCT). The median time from HSCT to BSI was 62 days (interquartile range, 9 to 182 days). Gram-positive cocci accounted for 56.7% of the episodes; gram-negative bacilli, for 42%. The most common microorganisms were coagulase-negative staphylococci (30.6%) and Pseudomonas aeruginosa (15.9%). MDR gram-negative bacilli caused 11.9% of all episodes. Clinical characteristics, source of BSI, etiology, and outcomes changed depending on time since HSCT. Globally, 26.6% of episodes were treated with inappropriate empiric antibiotic therapy, more frequently in BSI episodes caused by P. aeruginosa, MDR P. aeruginosa, and MDR gram-negative bacilli. The 30-day mortality was 19.2%. Independent risk factors for mortality were BSI occurring ≥30 days after HSCT (odds ratio [OR], 11.21; 95% confidence interval [CI], 4.63 to 27.19), shock (OR, 7.10; 95% CI, 2.98 to 16.94), BSI caused by MDR P. aeruginosa (OR, 4.45; 95% CI, 1.12 to 17.72), and inappropriate empiric antibiotic therapy for gram-negative bacilli or Candida spp. (OR, 3.73; 95% CI, 1.27 to 10.89). HSCT recipients experiencing BSI have high mortality related to host and procedure factors, causative microorganism, and empiric antibiotic therapy. Strategies to identify HSCT recipients at risk of MDR P. aeruginosa and reducing inappropriate empiric antibiotic therapy are paramount to reduce mortality.

The importance of appropriate diagnostics in prosthetic joint infection: letter to the editor of BMC musculoskeletal disorders

Assessment of a new diagnostic test must be performed against an acceptable and validated standard to allow comparison with other studies. We are concerned that the adoption of lower diagnostic criteria in this paper has contributed to an over-diagnosis of prosthetic joint infection and makes interpretation of the results difficult.

Real-life use of remdesivir in hospitalized patients with COVID-19

Objective

Controversial results on remdesivir efficacy have been reported. We aimed to report our real-life experience with the use of remdesivir from its availability in Spain.

Methods

We performed a descriptive study of all patients admitted for ≥48 hours with confirmed COVID-19 who received remdesivir between the 1st of July and the 30th of September 2020.

Results

A total of 123 patients out of 242 admitted with COVID-19 at our hospital (50.8%) received remdesivir. Median age was 58 years, 61% were males and 56.9 % received at least one anti-inflammatory treatment. No adverse events requiring remdesivir discontinuation were reported. The need of intensive care unit admission, mechanical ventilation and 30-days mortality were 19.5%, 7.3% and 4.1%, respectively.

Conclusion

In our real-life experience, the use of remdesivir in hospitalized patients with COVID-19 was associated with a low mortality rate and good safety profile.

Clinical characteristics and outcome of patients aged over 80 years with covid-19

ABSTRACT

To investigate the clinical characteristics and outcome of octogenarians with covid-19.This is a observational, retrospective, descriptive study.Consecutive patients aged >80 years who were admitted for covid-19 pneumonia during a 6 weeks period (March 20-April 30, 2020).Illness severity on admission was classified according to World Health Organization (WHO) criteria: mild, moderate, severe, and critical. Data collected included demographics, presenting symptoms, radiological and laboratory findings, comorbidities, functional status, treatment, and clinical outcome.There were 159 patients (52.2% women) with a median age of 85.99 (IQR: 80-98). The median Barthel index was 90 (40-100) and Charlson index was 5 (5-6). Most common presenting symptoms were fever, dyspnea, and cough. Patients had mild (8.2%), moderate (52.2%), or severe (39.6%) illness according to WHO criteria. A bilateral pulmonary involvement was seen in 86% of patients. Laboratory analysis revealed increased serum concentrations of inflammatory parameters (C-reactive protein, ferritin, lactate dehydrogenase, and D-dimer) with an abnormal lymphocyte count [0.88 × 109/L (0.5)]. Treatments included corticosteroids in 37%, and biological therapies in 17.6%. Fifty three (33.3%) patients died during hospitalization, with a median time from admission to death of 3 (IQR 1-6) days. Mortality was higher in men (55%). Deceased patients had a significantly higher frequency of dyspnea, increased inflammatory parameters, and illness severity compared to survivors.One-third of octogenarians with covid-19 died during hospitalization and most had bilateral lung involvement. A further knowledge of the characteristics and outcome of this population may assist clinicians in the decision-making process in these patients.

Factors Associated With Short-Term Eradication of Rectal Colonization by KPC-2 Producing Klebsiella pneumoniae in an Outbreak Setting

Background: KPC-producing Klebsiella pneumoniae (KPCKP) is a threat for patients admitted to healthcare institutions.

Objectives: To assess the efficacy of several decolonization strategies for KPCKP rectal carriage.

Methods: Observational study performed in a 750-bed university center from July to October 2018 on the efficacy of a 10-day non-absorbable oral antibiotic (NAA) regimen (colistin 10 mg/ml, amikacin 8 mg/ml, and nystatin 30 mg/ml, 10 ml/6 h) vs. the same regimen followed by a probiotic (Vivomixx®) for 20 days in adult patients with KPCKP rectal colonization acquired during an outbreak.

Results: Seventy-three patients colonized by KPCKP were included, of which 21 (29%) did not receive any treatment and 52 (71.2%) received NAA either alone (n = 26, 35.6%) or followed by a probiotic (n = 26, 35.6%). Eradication was observed in 56 (76.7%) patients and the only variable significantly associated with it was not receiving systemic antibiotics after diagnosis of rectal carriage [22/24 (91.6%) vs. 34/49 (69.3%), p = 0.04]. Eradication in patients receiving NAA plus probiotic was numerically but not significantly higher than that of controls [23/26 (88.4%) vs. 15/21 (71.4%), p = 0.14] and of those receiving only NAA (OR = 3.4, 95% CI = 0.78–14.7, p = 0.09).

Conclusion: In an outbreak setting, rectal carriage of KPCKP persisted after a mean of 36 days in about one quarter of patients. The only factor associated with eradication was not receiving systemic antibiotic after diagnosis. A 10-day course of NAA had no impact on eradication. Probiotics after NAA may increase the decolonization rate, hence deserving further study.

Trends in mortality of hospitalised COVID-19 patients: A single centre observational cohort study from Spain

Background

We aimed to describe changes in characteristics and treatment strategies of hospitalised patients with COVID-19 and detail the mortality trend over time.

Methods

Observational cohort study of all consecutive patients admitted ≥ 48 h to Hospital Clinic of Barcelona for COVID-19 (1 March-30 September 2020).

Findings

A total of 1645 consecutive patients with COVID-19 were assessed over a 7-month period. Overall mortality (≤30 days) was 9.7% (159 patients), 7.7% in patients hospitalised in regular wards and 16.7 % in patients requiring ICU admission. Overall mortality decreased from 11.6% in the first month to 1.4% in the last month, reflecting a progressive, significant downward trend (p for trend <0.001). Patients' age changed over time, peaking in June. Most changes in the use of antivirals and anti-inflammatory treatments were documented. Age (OR 1.1, CI 1.1-1.12), chronic heart disease, (OR 1.7, CI 1.1-2.9), D-dimer>700 ng/mL (OR 2.3, CI 1.3-4.1), ferritin>489 ng/mL (OR 1.9; CI 1.5-3.2), C-RP>7 mg/dL (OR 2.6; CI 1.5-4.6), and shorter duration from symptom onset to hospital admission (OR 1.11; CI 1.04-1.17) were factors associated with 30-day mortality at hospital admission. Conversely, hospital admission in the last months (OR 0.80; CI 0.65-0.98) was significantly associated with lower mortality.

Interpretation

In-hospital mortality has decreased in patients with COVID-19 over the last, few months, even though main patient characteristics remain similar. Several changes made when managing patients may explain this decreasing trend. Our study provides current data on mortality of patients hospitalised with COVID-19 that might be useful in establishing quality of standard of care.

Funding

EIT Health, European Union´s Horizon 2020 Research and Innovation Programme), EDRD. PPA [CM18/00132], NGP [FI19/00133], and CGV [FIS PI18/01061], have received grants from Ministerio de Sanidad y Consumo, ISCIII.

The EBJIS definition of periprosthetic joint infection

Aims

The diagnosis of periprosthetic joint infection (PJI) can be difficult. All current diagnostic tests have problems with accuracy and interpretation of results. Many new tests have been proposed, but there is no consensus on the place of many of these in the diagnostic pathway. Previous attempts to develop a definition of PJI have not been universally accepted and there remains no reference standard definition.

Methods

This paper reports the outcome of a project developed by the European Bone and Joint Infection Society (EBJIS), and supported by the Musculoskeletal Infection Society (MSIS) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Implant-Associated Infections (ESGIAI). It comprised a comprehensive review of the literature, open discussion with Society members and conference delegates, and an expert panel assessment of the results to produce the final guidance.

Results

This process evolved a three-level approach to the diagnostic continuum, resulting in a definition set and guidance, which has been fully endorsed by EBJIS, MSIS, and ESGIAI.

Conclusion

The definition presents a novel three-level approach to diagnosis, based on the most robust evidence, which will be useful to clinicians in daily practice.

Cite this article: Bone Joint J 2021;103-B(1):18–25.

Systematic review on estimated rates of nephrotoxicity and neurotoxicity in patients treated with polymyxins

BACKGROUND

Nephrotoxicity and neurotoxicity are commonly associated with polymyxin treatment; however, the emergence of multidrug-resistant Gram-negative bacteria with limited therapeutic options has resulted in increased use of polymyxins.

OBJECTIVES

To determine the rates of nephrotoxicity and neurotoxicity during polymyxin treatment and whether any factors influence these.

DATA SOURCES

Medline, Embase and Cochrane Library databases were searched on 2 January 2020.

STUDY ELIGIBILITY CRITERIA

Studies reporting nephrotoxicity and/or neurotoxicity rates in patients with infections treated with polymyxins were included. Reviews, meta-analyses and reports not in English were excluded.

PARTICIPANTS

Patients hospitalized with infections treated with systemic or inhaled polymyxins were included. For comparative analyses, patients treated with non-polymyxin-based regimens were also included.

METHODS

Meta-analyses were performed using a random-effects model; subgroup meta-analyses were conducted where data permitted using a mixed-effects model.

RESULTS

In total, 237 reports of randomized controlled trials, cohort and case-control studies were eligible for inclusion; most were single-arm observational studies. Nephrotoxic events in 35,569 patients receiving polymyxins were analysed. Overall nephrotoxicity rate was 0.282 (95% confidence interval (CI) 0.259-0.307). When excluding studies where >50% of patients received inhaled-only polymyxin treatment or nephrotoxicity assessment was by methods other than internationally recognized criteria (RIFLE, KDIGO or AKIN), the nephrotoxicity rate was 0.391 (95% CI 0.364-0.419). The odds of nephrotoxicity were greater with polymyxin therapies compared to non-polymyxin-based regimens (odds ratio 2.23 (95% CI 1.58-3.15); p < 0.001). Meta-analyses showed a significant effect of polymyxin type, dose, patient age, number of concomitant nephrotoxins and use of diuretics, glycopeptides or vasopressors on the rate of nephrotoxicity. Polymyxin therapies were not associated with a significantly different rate of neurotoxicity than non-polymyxin-based regimens (p 0.051). The overall rate of neurotoxicity during polymyxin therapy was 0.030 (95% CI 0.020-0.043).

CONCLUSIONS

Polymyxins are associated with a higher risk of nephrotoxicity than non-polymyxin-based regimens.

Inappropriate Empirical Antibiotic Treatment in High-risk Neutropenic Patients With Bacteremia in the Era of Multidrug Resistance

BACKGROUND

We aimed to describe the current rates of inappropriate empirical antibiotic treatment (IEAT) in oncohematological patients with febrile neutropenia (FN) and its impact on mortality.

METHODS

This was a multicenter prospective study of all episodes of bloodstream infection (BSI) in high-risk FN patients (2006-2017). Episodes receiving IEAT were compared with episodes receiving appropriate empirical therapy. Adherence to Infectious Diseases Society of America (IDSA) recommendations was evaluated. Multivariate analysis was performed to identify independent risk factors for mortality in Pseudomonas aeruginosa episodes.

RESULTS

Of 1615 episodes, including Escherichia coli (24%), coagulase-negative staphylococci (21%), and P. aeruginosa (16%), 394 (24%) received IEAT despite IDSA recommendations being followed in 87% of cases. Patients with multidrug-resistant gram-negative bacilli (MDR-GNB), accounting for 221 (14%) of all isolates, were more likely to receive IEAT (39% vs 7%, P < .001). Overall mortality was higher in patients with GNB BSI who received IEAT (36% vs 24%, P = .004); when considering individual microorganisms, only patients with infection caused by P. aeruginosa experienced a significant increase in mortality when receiving IEAT (48% vs 31%, P = .027). Independent risk factors for mortality in PA BSI (odds ratio [95% confidence interval] were IEAT (2.41 [1.19-4.91]), shock at onset (4.62 [2.49-8.56]), and pneumonia (3.01 [1.55-5.83]).

CONCLUSIONS

IEAT is frequent in high-risk patients with FN and BSI, despite high adherence to guidelines. This inappropriate treatment primarily impacts patients with P. aeruginosa-related BSI mortality and in turn is the only modifiable factor to improve outcomes.

The first wave of the COVID-19 epidemic in Spain was associated with early introductions and fast spread of a dominating genetic variant

The coronavirus disease 2019 (COVID-19) pandemic has affected the world radically since 2020. Spain was one of the European countries with the highest incidence during the first wave. As a part of a consortium to monitor and study the evolution of the epidemic, we sequenced 2,170 samples, diagnosed mostly before lockdown measures. Here, we identified at least 500 introductions from multiple international sources and documented the early rise of two dominant Spanish epidemic clades (SECs), probably amplified by superspreading events. Both SECs were related closely to the initial Asian variants of SARS-CoV-2 and spread widely across Spain. We inferred a substantial reduction in the effective reproductive number of both SECs due to public-health interventions (R_e < 1), also reflected in the replacement of SECs by a new variant over the summer of 2020. In summary, we reveal a notable difference in the initial genetic makeup of SARS-CoV-2 in Spain compared with other European countries and show evidence to support the effectiveness of lockdown measures in controlling virus spread, even for the most successful genetic variants.

Incidence of co-infections and superinfections in hospitalized patients with COVID-19: a retrospective cohort study

OBJECTIVES

To describe the burden, epidemiology and outcomes of co-infections and superinfections occurring in hospitalized patients with coronavirus disease 2019 (COVID-19).

METHODS

We performed an observational cohort study of all consecutive patients admitted for ≥48 hours to the Hospital Clinic of Barcelona for COVID-19 (28 February to 22 April 2020) who were discharged or dead. We describe demographic, epidemiologic, laboratory and microbiologic results, as well as outcome data retrieved from electronic health records.

RESULTS

Of a total of 989 consecutive patients with COVID-19, 72 (7.2%) had 88 other microbiologically confirmed infections: 74 were bacterial, seven fungal and seven viral. Community-acquired co-infection at COVID-19 diagnosis was uncommon (31/989, 3.1%) and mainly caused by Streptococcus pneumoniae and Staphylococcus aureus. A total of 51 hospital-acquired bacterial superinfections, mostly caused by Pseudomonas aeruginosa and Escherichia coli, were diagnosed in 43 patients (4.7%), with a mean (SD) time from hospital admission to superinfection diagnosis of 10.6 (6.6) days. Overall mortality was 9.8% (97/989). Patients with community-acquired co-infections and hospital-acquired superinfections had worse outcomes.

CONCLUSIONS

Co-infection at COVID-19 diagnosis is uncommon. Few patients developed superinfections during hospitalization. These findings are different compared to those of other viral pandemics. As it relates to hospitalized patients with COVID-19, such findings could prove essential in defining the role of empiric antimicrobial therapy or stewardship strategies.

Executive summary of the Consensus Document of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and of the Spanish Association of Surgeons (AEC) in antibiotic prophylaxis in surgery

Antibiotic prophylaxis in surgery is one of the most effective measures for preventing surgical site infection, although its use is frequently inadequate and may even increase the risk of infection, toxicities and bacterial resistance. As a result of advances in surgical techniques and the emergence of multidrug-resistant organisms, the current guidelines for prophylaxis need to be revised. La Sociedad Española de Enfermedades Infecciosas (Spanish Society of Infectious Diseases and Clinical Microbiology) (SEIMC) together with the Asociación Española de Cirujanos (Spanish Association of Surgeons) (AEC) have revised and updated the recommendations for antibiotic prophylaxis to adapt them to any type of surgical intervention and to current epidemiology. This document gathers together the recommendations on antimicrobial prophylaxis in the various procedures, with doses, duration, prophylaxis in special patient groups, and in epidemiological settings of multidrug resistance to facilitate standardized management and the safe, effective and rational use of antibiotics in elective surgery.

Executive summary of the Consensus Document of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and of the Spanish Association of Surgeons (AEC) in antibiotic prophylaxis in surgery

Antibiotic prophylaxis in surgery is one of the most effective measures for preventing surgical site infection, although its use is frequently inadequate and may even increase the risk of infection, toxicities and antimicrobial resistance. As a result of advances in surgical techniques and the emergence of multidrug-resistant organisms, the current guidelines for prophylaxis need to be revised. The Sociedad Española de Enfermedades Infecciosas (Spanish Society of Infectious Diseases and Clinical Microbiology) (SEIMC) together with the Asociación Española de Cirujanos (Spanish Association of Surgeons) (AEC) have revised and updated the recommendations for antibiotic prophylaxis in surgery to adapt them to any type of surgical intervention and to current epidemiology. This document gathers together the recommendations on antimicrobial prophylaxis in the various procedures, with doses, duration, prophylaxis in special patient groups, and in epidemiological settings of multidrug resistance to facilitate standardized management and the safe, effective and rational use of antibiotics in elective surgery.

557. Impact of Concomitant Hydroxychloroquine Use on Safety and Efficacy of Remdesivir in Moderate COVID-19 Patients

Background

Remdesivir (RDV) has been shown to shorten recovery time and was well tolerated in patients with severe COVID-19. Hydroxychloroquine (HQN) is an experimental treatment for COVID-19. Effects of coadministration of HQN with RDV have not been studied and are relevant given the long half-life (~22 days) of HQN. We report the impact of concomitant HQN and RDV use on clinical outcomes and safety in patients with moderate COVID-19.

Methods

We enrolled hospitalized patients with confirmed SARS-CoV-2 infection, oxygen saturation >94% on room air, and radiological evidence of pneumonia. Patients were randomized 1:1:1 to receive 5d or 10d of intravenous RDV once daily plus standard of care (SoC), or SoC only. We compared patients on concomitant HQN (HQN^pos) vs not (HQN^neg). Clinical recovery was evaluated using Cox proportional hazards. Covariate adjustment included age, sex, race, region, symptom duration, oxygen support status and obesity. Recovery and adverse events (AEs) were assessed through death, discharge, or d14.

Results

Of 584 patients, 199 (34%) received HQN (5d RDV: n=57 [30%]; 10d RDV, n=49 [25%]; SoC: n=93 [47%]). Through median follow-up of 13d (range 1-41d), HQN^pos patients on 5d or 10d RDV had a lower recovery rate (adjusted HR [95% CI] 0.78 [0.59, 1.03], p=0.09) with longer median time to recovery (8 vs 6 days) compared to HQN^neg. HQN^pos compared to HQN^neg patients in 5d RDV showed a trend of reduced recovery rate (HR: 0.69 [0.45,1.04], p=0.080); such an effect was not observed in 10d RDV or SoC (Table 1). More HQN^pos than HQN^neg patients had AEs in RDV (5/10d) or SoC arms evaluated separately, and all arms combined. This difference was significant for AEs and SAEs for all arms combined after covariate adjustment (Table 2).

Table 1.

Table 2.

Conclusion

In moderate COVID-19 patients, concomitant HQN may delay recovery on RDV and showed no impact on recovery with SoC alone. The AE profile of HQN^pos patients was worse than that observed for HQN^neg patients, regardless of RDV treatment.

Disclosures

Jose Ramon Arribas, MD, Alexa (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Gilead Sciences Inc. (Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Janssen (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Merck (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Viiv Healthcare (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees) Jose Ramon Arribas, MD, NO DISCLOSURE DATA Arun J. Sanyal, MD, AbbVie (Consultant)Akarna (Shareholder)Amarin (Consultant)Ardelyx (Consultant)Astra Zeneca (Consultant, Research Grant or Support)Boehringer (Consultant)Bristol Myers Squibb (Research Grant or Support)Conatus (Consultant)Cumberland (Research Grant or Support)Durect (Shareholder)Elsevier (Other Financial or Material Support, Royalties)Exhalenz (Shareholder)Fibrogen (Consultant)Genfit (Shareholder)Gilead Sciences Inc. (Consultant, Scientific Research Study Investigator, Research Grant or Support)Haemoshear (Shareholder)Indalo (Shareholder)Intercept (Research Grant or Support)Jannsen (Consultant)Lilly (Consultant)Malinckrodt (Research Grant or Support)Merck (Research Grant or Support)Nimbus (Consultant)Nitto Denko (Consultant)Novartis (Consultant)Pfizer (Consultant)Salix (Consultant)Sanyal Biotechnology (Employee, Shareholder, Other Financial or Material Support, President)Shire (Research Grant or Support)Takeda (Consultant)Tiziana (Shareholder)Tobira (Consultant)UptoDate (Other Financial or Material Support, Royalties)Zafgen (Consultant) Bum Sik Chin, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Bum Sik Chin, MD, NO DISCLOSURE DATA Shirin Kalimuddin, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Stefan Schreiber, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Emon Elboudwarej, PhD, Gilead Sciences Inc. (Employee, Shareholder) Yuan Tian, PhD, Gilead Sciences Inc. (Employee, Shareholder) Robert H. Hyland, MD, Gilead Sciences Inc. (Employee, Shareholder) Devi SenGupta, MD, Gilead Sciences Inc. (Employee, Shareholder) Anand Chokkalingam, PhD, Gilead Sciences (Employee) Anu Osinusi, MD, Gilead Sciences (Employee) Diana M. Brainard, MD, Gilead Sciences (Employee) Christoph Lübbert, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Chien Boon Lye, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Chien Boon Lye, MD, NO DISCLOSURE DATA Judith A. Aberg, MD, Theratechnology (Consultant) Enrique Navas Elorza, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Karen T. Tashima, MD, Bristol-Myers Squibb (Research Grant or Support)Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator)GlaxoSmithKline (Research Grant or Support)Merck (Research Grant or Support)Tibotec (Research Grant or Support)Viiv Healthcare (Research Grant or Support) Mark McPhail, MD, Gilead Sciences Inc. (Scientific Research Study Investigator)

1284. Outcomes by Baseline Pathogens and Susceptibility in the STRIVE Phase 2 Trial of Once-Weekly Rezafungin for Treatment of Candidemia and Invasive Candidiasis Compared with Caspofungin

Background

Rezafungin (RZF) is a novel echinocandin in Phase 3 development for treatment of candidemia and invasive candidiasis (IC) and for prevention of invasive fungal disease caused by Candida, Aspergillus, and Pneumocystis in blood and marrow transplant recipients. This analysis of the completed Phase 2 STRIVE trial (NCT02734862) of RZF treatment was conducted to evaluate outcomes based on baseline pathogen and susceptibility.

Methods

In STRIVE, adults (≥ 18 y) with systemic signs and mycological evidence of candidemia and/or IC were randomized to either RZF once weekly or caspofungin (CAS) once daily for ≥ 14 days (Fig. 1). The primary efficacy endpoint was Overall Response (resolution of clinical signs of infection + mycological eradication) at Day 14. For this analysis, outcomes by treatment group were stratified by Candida species and by its in vitro susceptibility (CLSI broth microdilution MIC values; M27-Ed4).

Figure 1. Treatment Groups of the Phase 2 STRIVE Trial

Results

A total of 196 Candida isolates were recovered from 183 patients across all treatment groups (Fig. 2). C. albicans was the most common species, followed by C. glabrata, C. parapsilosis, and C. tropicalis; non-albicans Candida comprised 54% of all baseline isolates (Fig. 2). Among all clinical isolates, MIC distributions and ranges for RZF were generally lower than or comparable to those for CAS (Table 1). The rate of Overall Response (as defined above) against C. parapsilosis was lower for CAS than for RZF (Table 2). Overall, outcomes by Candida species and MIC did not appear to be affected by MIC values for either RZF or CAS (Table 1).

Figure 2. Candida Species Distribution and MIC ranges in the Phase 2 STRIVE Trial (mITT)

Table 1. Overall Response Rates (%) for Most Frequently Isolated Candida Species at Baseline by Treatment Group and MIC Values (mITT)

Table 2. Overall Response Rates (%) for Most Frequently Isolated Candida Species at Baseline by Treatment Group (mITT)

Conclusion

This analysis demonstrated RZF efficacy across multiple Candida species. RZF outcomes were similar to or better than those for CAS regardless of species identified. There was no clear correlation between increased MICs and clinical outcomes although, based on MICs, all isolates exhibited a wild-type in vitro susceptibility profile. These findings from STRIVE, together with future analyses from the ongoing Phase 3 trial of RZF treatment of candidemia and IC (ReSTORE; NCT03667690), will further our understanding of the relationships between MIC values and clinical outcomes in patients with candidemia or IC.

Disclosures

Jeffrey B. Locke, PhD, Cidara Therapeutics, Inc. (Employee, Shareholder) Rolando Viani, MD, Cidara Therapeutics, Inc. (Employee, Shareholder) Peter Pappas, MD, SCYNEXIS, Inc. (Consultant, Advisor or Review Panel member, Research Grant or Support) Mahmoud Ghannoum, PhD, Amplyx (Grant/Research Support)Cidara (Grant/Research Support)Scynexis (Consultant, Grant/Research Support) Taylor Sandison, MD, MPH, Cidara Therapeutics, Inc. (Employee, Shareholder)

1612. Evaluation of the Use of Ceftolozane/Tazobactam for the Treatment of ESBL-producing Enterobacterales Infections Using International Data from SPECTRA (Study of Prescribing Patterns and Effectiveness of Ceftolozane/Tazobactam Real World Analysis)

Background

There is a paucity of data on outcomes of patients with severe ESBL-producing Enterobacterales infections treated with empiric or directed ceftolozane/tazobactam (C/T). This study looked at the treatment patterns and outcomes associated with C/T use in the treatment of ESBL-producing Enterobacterales.

Methods

Data were collected from an international cohort of 32 hospitals in 6 countries as part of SPECTRA, a retrospective multicenter database of C/T use globally, from 2016 – 2019. All adult patients with an ESBL positive Enterobacterales sterile site culture and treated with ≥ 48 hours of C/T were eligible. Outcomes assessed were clinical success, 30-day mortality from index event and readmission.

Results

There were 59 patients with 121 ESBL positive isolates. Blood and urine were the most common sites of infection at 19.8% each, followed by respiratory (18.2%). E. coli (50%) and K. pneumoniae (30%) were the most common pathogens. On average patients had 2 positive ESBL isolates; median 1; range 1-15. Most patients had the same infection site and ESBL pathogen, however 13 had multi-site ESBL pathogens identified and only 2 had polymicrobial ESBL pathogens. Septic shock was observed in 14 (24%) patients; 29 (49%) were in the ICU at the onset of infection. The most common comorbid conditions were immunocompromised hosts (37%) and cardiac disease (32%). 29% of patients were transplant recipients, and 28% had a CrCl < 50 ml/min. In most patients (71%), C/T was given as directed therapy (i.e., once culture results were available). C/T was given prior to culture results (i.e., as empiric therapy) in 17 (29%) patients, of which 77% had clinical success. C/T dose was 1.5 g in 49%. Only 2 of 10 patients with a respiratory source received the currently licensed 3 g dose. Overall, clinical success was observed in 36 (61%) patients. 30-day mortality was 12%. Readmissions occurred in 5%, of which 2 were infection related.

Conclusion

The role of newer non-carbapenem antibiotics in the treatment of severe ESBL infections is currently undefined. In a multinational patient database, C/T was found to be effective in severe infections caused by ESBL-producing Enterobacterales. Prospective studies are needed to further define the role of C/T in the setting of frequent drug-resistant Gram-negative pathogens.

Disclosures

Laura A. Puzniak, PhD, Merck (Employee) Matteo Bassetti, MD, Shionogi Inc. (Advisor or Review Panel member) Pamela Moise, PharmD, Merck & Co., Inc. (Employee, Shareholder) David Paterson, Accelerate (Speaker’s Bureau)BioMerieux (Speaker’s Bureau)BioMerieux (Advisor or Review Panel member)Entasis (Advisor or Review Panel member)Merck (Advisor or Review Panel member)Merck (Grant/Research Support)Merck (Speaker’s Bureau)Pfizer (Speaker’s Bureau)Shionogi & Co., Ltd. (Grant/Research Support)VenatoRx (Advisor or Review Panel member)

Vogt-Koyanagi-Harada patients show higher frequencies of circulating NKG2Dpos NK and NK T cells

Vogt-Koyanagi-Harada (VKH) is an autoimmune disease characterized by inflammation in tissues that contain melanocytes. We aimed to increase the knowledge regarding immunological pathways deregulated in VKH disease. We compared the percentages of circulating natural killer (NK), NK T and T cells expressing the activatory markers: CD16, CD69, NK group 2D (NKG2D), natural cytotoxicity triggering receptor 3 (Nkp30), natural cytotoxicity triggering receptor 1 (Nkp46) and the inhibitory marker: NK group 2 member A (NKG2A) in 10 active VKH patients, 20 control subjects (CTR) and seven patients with Behçet disease (BD) by flow cytometry. Cytotoxic potential of NK cells was determined through the degranulation marker CD107a expression after contact with K562 cells by flow cytometry. Moreover, plasmatic levels of 27 cytokines were determined with a multiplex bead-based assay. VKH patients showed higher percentages of NKG2D^pos NK and NK T cells versus CTR. The cytotoxic potential of NK cells induced by K562 cells was comparable between VKH patients and CTR. Finally, higher concentrations of interleukin (IL)-4, IL-5, IL-7, IL-17 and platelet-derived growth factor-subunits B (PDGF-bb) were detected in plasma of VKH patients versus CTR. The immune profile of VKH patients was similar to that of BD patients.

Impact of low serum calcium at hospital admission on SARS-CoV-2 infection outcome

Background

Calcium is an essential ion for pathogen survival and virulence and is involved in the regulation of the inflammatory response. Hypocalcemia is a common laboratory finding in critically ill patients. Data regarding levels of calcium in SARS-CoV-2 infection is scarce. Patients with SARS-CoV-2 infection who present with hypocalcemia could have a worse outcome.

Methods

We performed a retrospective analysis of hospitalized patients with SARS-CoV-2 infection and included all patients who had any serum calcium measurement in the first 72 h since hospital admission. The main objective was to investigate the relation of low serum calcium with adverse outcome, measured by the requirement of high oxygen support – defined as high flow nasal cannula oxygen, non-invasive mechanical ventilation and/or invasive ventilation – intensive care unit admission or death.

Results

A total of 316 patients were included in the study. Median age was 65 years (IQR 55–74); 65% were men. Hypocalcemia within 72 h since hospital admission was present in 63% of patients. A higher number of patients in the hypocalcemia group required high oxygen support during hospitalization (49% vs 32%; p = 0,01) and were admitted to the ICU (42% vs 26%; p = 0,005). No differences in mortality were observed between groups.

Conclusions

Hypocalcemia is frequent in hospitalized patients with SARS-CoV-2 infection and can identify patients who will have a worse outcome. More studies are needed to understand the role of calcium metabolism in SARS-CoV-2 infection and to address the clinical implications and therapeutic interventions it might have.

A multidisciplinary registry of patients with autoimmune and immune-mediated diseases with symptomatic COVID-19 from a single center

Background and aim

There is increasing interest regarding SARS-CoV-2 infection in patients with autoimmune and immune-mediated inflammatory diseases (AI/IMID) with some discrepancies in different cohorts about their risk and outcomes. The aim was to describe a multidisciplinary cohort of patients with AI/IMID and symptomatic SARS-CoV-2 infection in a single tertiary center and analyze sociodemographic, clinical, and therapeutic factors associated with poor outcomes.

Methods

A retrospective observational study was conducted from the 1st of March until May 29th, 2020 in a University tertiary hospital in Barcelona, Spain. Patients with an underlying AI/IMID and symptomatic SARS-CoV-2 infection were identified in our local SARS-CoV-2 infection database. Controls (2:1) were selected from the same database and matched by age and gender. The primary outcome was severe SARS-CoV-2 infection, which was a composite endpoint including admission to the intensive care unit (ICU), need for mechanical ventilation (MV), and/or death. Several covariates including age, sex, and comorbidities among others were combined into a multivariate model having severe SARS-CoV-2 as the dependent variable. Also, a sensitivity analysis was performed evaluating AID and IMID separately.

Results

The prevalence of symptomatic SARS-CoV-2 infection in a cohort of AI/IMID patients was 1.3%. Eighty-five patients with AI/IMID and symptomatic SARS-CoV-2 were identified, requiring hospitalization in 58 (68%) cases. A total of 175 patients admitted for SARS-CoV-2 (58 with AI/IMID and 117 matched-controls) were analyzed. In logistic regression analysis, a significant inverse association between AI/IMID group and severe SARS-CoV-2 (OR 0.28; 95% CI 0.12–0.61; p = 0.001), need of MV (OR 0.20; IC 95% 0.05–0.71; p = 0.014), and ICU admission (OR 0.25; IC 95% 0.10–0.62; p = 0.003) was found.

Conclusions

Patients with AI/IMID who require admission for SARS-CoV-2 infection have a lower risk of developing severe disease, including the need to stay in the ICU and MV.

•

Patients with AI/IMID fwho required admission for SARS CoV2 infection have a lower risk of developing severe disease.

•

Among patients with AID and IMID, there were no differences in terms of severity.

•

According to the 7-category ordinal scale, maximum oxygen requirement was lower among AI/IMID group.

Lack of efficacy of standard doses of ivermectin in severe COVID-19 patients

Ivermectin has recently shown efficacy against SARS-CoV-2 in-vitro. We retrospectively reviewed severe COVID-19 patients receiving standard doses of ivermectin and we compared clinical and microbiological outcomes with a similar group of patients not receiving ivermectin. No differences were found between groups. We recommend the evaluation of high-doses of ivermectin in randomized trials against SARS-CoV-2.

Chronic prosthetic joint infections with a draining sinus. Who should receive suppressive antibiotic treatment?

The benefit of suppressive antibiotic treatment in inoperable patients with a chronic periprosthetic joint infection and a sinus tract is unknown. Some physicians prefer to just let the sinus drain, while others prefer antibiotic treatment. In this viewpoint article we discuss the advantages and disadvantages of suppressive antibiotic treatment in this particular patient group.

Donor selection for faecal microbiota transplantation. Consensus document of the Catalan Society of Gastroenterology and the Catalan Society of Infectious Diseases and Clinical Microbiology

Faecal microbiota transplantation (FMT) is an effective and safe treatment of recurrent Clostridioides difficile infection. It is essential to make every effort to perform FMT rigorously and based on scientific knowledge. Selection of the faecal microbiota donor is a key part of the process to ensure recipient safety. Protocols of action must be implemented that allow clinicians to act with the maximum guarantees and to minimise the risks of the procedure. In this regard, a multidisciplinary working group has been set up with the aim of establishing recommendations for selecting the faecal microbiota donor.

Comparison of the diagnostic accuracy of diffusion-weighted and dynamic contrast-enhanced MRI with 18F-FDG PET/CT to differentiate osteomyelitis from Charcot neuro-osteoarthropathy in diabetic foot

PURPOSE

To compare the diagnostic accuracy of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI) involving two region of interest (ROI) sizes with 18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) to differentiate diabetic foot osteomyelitis (DFO) from Charcot neuro-osteoarthropathy (CN).

METHOD

Thirty-one diabetic patients were included in this prospective study. Two readers independently evaluated DWI (apparent diffusion coefficient [ADC] and high-b-value signal pathological-to-normal bone ratio [DWIr]) and DCE-MRI parameters (K^trans, K_ep, V_e, internal area under the gadolinium curve at 60 s [iAUC₆₀] and time intensity curve [TIC]) using two different ROI sizes, and ¹⁸F-FDG PET/CT parameters (visual assessment, SUV_max, delayed SUV_max, and percentage changes between SUV_max and delayed SUV_max). Techniques were compared by univariate analysis using the area under the receiver operating characteristic curve [AUC]. Reliability was analyzed with Kappa and Intraclass correlation [ICC].

RESULTS

DWIr, K^trans and iAUC₆₀ showed better diagnostic accuracy (AUC = 0.814-0.830) and reliability (ICC > 0.9) for large than for small ROIs (AUC = 0.736-0.750; ICC = 0.6 in K^trans, 0.8 in DWIr and iAUC₆₀). TIC showed moderate diagnostic performance (AUC = 0.739-0.761) and reliability (κ 0.7). Visual assessment of ¹⁸F-FDG PET/CT demonstrated a significantly higher accuracy (AUC = 0.924) than MRI parameters. Semi-quantitative ¹⁸F-FDG PET/CT parameters did not provide significant improvement over visual analysis (AUC = 0.848-0.903).

CONCLUSION

DWIr, K^trans and iAUC₆₀ allowed reliable differentiation of DFO and CN, particularly for large ROIs. Visual assessment of ¹⁸F-FDG PET/CT was the most accurate technique for differentiation.

Rezafungin versus Caspofungin in a Phase 2, Randomized, Double-Blind Study for the Treatment of Candidemia and Invasive Candidiasis- The STRIVE Trial

Background

Rezafungin (RZF) is a novel echinocandin exhibiting distinctive pharmacokinetics/pharmacodynamics. STRIVE was a phase 2, double-blind, randomized trial designed to compare the safety and efficacy of RZF once weekly (QWk) to caspofungin (CAS) once daily for treatment of candidemia and/or invasive candidiasis (IC).

Methods

Adults with systemic signs and mycological confirmation of candidemia and/or IC were randomized to RZF 400 mg QWk (400 mg), RZF 400 mg on week 1 then 200 mg QWk (400/200 mg), or CAS 70 mg as a loading dose followed by 50 mg daily for ≤4 weeks. Efficacy assessments included overall cure (resolution of signs of candidemia/IC + mycological eradication) at day 14 (primary endpoint), investigator-assessed clinical response at day 14, and 30-day all-cause mortality (ACM) (secondary endpoints), and time to negative blood culture. Safety was evaluated by adverse events and ACM through follow-up.

Results

Of 207 patients enrolled, 183 were in the microbiological intent-to-treat population (~21% IC). Overall cure rates were 60.5% (46/76) for RZF 400 mg, 76.1% (35/46) for RZF 400/200 mg, and 67.2% (41/61) for CAS; investigator-assessed clinical cure rates were 69.7% (53/76), 80.4% (37/46), and 70.5% (43/61), respectively. In total, 30-day ACM was 15.8% for RZF 400 mg, 4.4% for RZF 400/200 mg, and 13.1% for CAS. Candidemia was cleared in 19.5 and 22.8 hours in RZF and CAS patients, respectively. No concerning safety trends were observed; ACM through follow-up was 15.2% (21/138) for RZF and 18.8% (13/69) for CAS.

Conclusions

RZF was safe and efficacious in the treatment of candidemia and/or IC.

Clinical Trials Registration

NCT02734862

Defining persistent Staphylococcus aureus bacteraemia: secondary analysis of a prospective cohort study

BACKGROUND

Staphylococcus aureus persistent bacteraemia is only vaguely defined and the effect of different durations of bacteraemia on mortality is not well established. Our primary aim was to analyse mortality according to duration of bacteraemia and to derive a clinically relevant definition for persistent bacteraemia.

METHODS

We did a secondary analysis of a prospective observational cohort study at 17 European centres (nine in the UK, six in Spain, and two in Germany), with recruitment between Jan 1, 2013, and April 30, 2015. Adult patients who were consecutively hospitalised with monomicrobial S aureus bacteraemia were included. Patients were excluded if no follow-up blood culture was taken, if the first follow-up blood-culture was after 7 days, or if active antibiotic therapy was started more than 3 days after first blood culture. The primary outcome was 90-day mortality. Univariable and time-dependent multivariable Cox regression analysis were used to assess predictors of mortality. Duration of bacteraemia was defined as bacteraemic days under active antibiotic therapy counting the first day as day 1.

FINDINGS

Of 1588 individuals assessed for eligibility, 987 were included (median age 65 years [IQR 51-75]; 625 [63%] male). Death within 90 days occurred in 273 (28%) patients. Patients with more than 1 day of bacteraemia (315 [32%]) had higher Charlson comorbidity index and sequential organ failure assessment scores and a longer interval from first symptom to first blood culture. Crude 90-day mortality increased from 22% (148 of 672) with 1 day of bacteraemia, to 39% (85 of 218) with 2-4 days, 43% (30 of 69) with 5-7 days, and 36% (10 of 28) with more than 7 days of bacteraemia. Metastatic infections developed in 39 (6%) of 672 patients with 1 day of bacteraemia versus 40 (13%) of 315 patients if bacteraemia lasted for at least 2 days. The second day of bacteraemia had the highest HR and earliest cutoff significantly associated with mortality (adjusted hazard ratio 1·93, 95% CI 1·51-2·46; p<0·0001).

INTERPRETATION

We suggest redefining the cutoff duration for persistent bacteraemia as 2 days or more despite active antibiotic therapy. Our results favour follow-up blood cultures after 24 h for early identification of all patients with increased risk of death and metastatic infection.

FUNDING

None.

Failure After 2-Stage Exchange Arthroplasty for Treatment of Periprosthetic Joint Infection: The Role of Antibiotics in the Cement Spacer

BACKGROUND

Failure after a 2-stage exchange surgery for periprosthetic joint infection (PJI) is high. Previous studies demonstrated that positive cultures at reimplantation are associated with failure afterward. The aim of this multicenter study was to define the role of antibiotics in the cement spacer in relation to reimplantation cultures and subsequent failure.

METHODS

We retrospectively evaluated 2-stage exchange procedures between 2000 and 2015. Culture-negative PJIs, cases in which no cultures were obtained during reimplantation, and cases without data on cement spacers were excluded.

RESULTS

Three hundred forty-four cases were included. The rate of positive cultures during reimplantation was 9.5% for cement spacers containing a glycopeptide (27/284) (with or without an aminoglycoside) vs 21.7% for those containing monotherapy with an aminoglycoside (13/60) (P = .008), and was mostly attributed by a reduction in coagulase-negative staphylococci (CoNS) (17% vs 2%, P < .001). The failure rate was >2-fold higher at 40.0% (16/40) in cases with positive cultures at reimplantation compared to 15.8% (48/304) for those with negative cultures (P < .001). Overall, a glycopeptide in the cement spacer was not associated with a lower failure rate (18% vs 23%, P = .3), but was associated with lower failure due to CoNS (2.5% vs 13.3%, P < .001).

CONCLUSIONS

In a 2-stage exchange procedure for PJI, adding a glycopeptide to the cement spacer reduces the rate of positive cultures during reimplantation and is associated with a lower failure rate due to CoNS afterward.

Impact of locking solutions on conditioning biofilm formation in tunnelled haemodialysis catheters and inflammatory response activation

INTRODUCTION

The surface of tunnelled cuffed catheters provides an optimal environment for the development of biofilms, which have recently been described as conditioning films because of the presence of adherent biological materials. These biofilms are associated with infection and thrombosis and potentially increase patients' inflammatory response. These complications could be reduced by the use of locking solutions.

OBJECTIVE

To analyse biofilm formation, using confocal and electron microscopy, in tunnelled cuffed catheters locked with three different solutions and to determine the relationship between these solutions and inflammatory response.

STUDY DESIGN

This prospective study included 35 haemodialysis patients with tunnelled cuffed catheter removal for non-infection-related reasons. The participants were divided into three groups according to the lock solution used: (1) heparin 1: 5000 IU; (2) citrate 4%; and (3) taurolidine 1.35%, citrate 4% and heparin 500 IU (taurolock); in the latter group, 25,000 IU taurolidine-urokinase was used in the last weekly session. All tunnelled cuffed catheters were cultured, and the inner surface was evaluated with confocal and electron microscopy. The inflammatory profile of included patients was determined at tunnelled cuffed catheter removal.

RESULTS

There were no differences in clinical or demographic variables between the three subgroups. Biofilm thickness was lower in the taurolidine group than in the citrate 4% and heparin groups (28.85 ± 6.86 vs 49.99 ± 16.56 vs 56.2 ± 15.67 µm, respectively; p < 0.001), as was biofilm volume (1.01 ±1.18 vs 3.7 ± 2.15 vs 5.55 ±2.44, µm³, respectively; p < 0.001). The mean interleukin-6 value was 39%, which was 50% lower than in the citrate and heparin groups, but without significance differences.

CONCLUSION

Our results show that biofilms were found in all tunnelled cuffed catheters, but the thickness and volume were significantly lower in tunnelled cuffed catheters locked with taurolidine solution. Therefore, the type of locking solution used in tunnelled cuffed catheters should maintain tunnelled cuffed catheter sterility and prevent catheter-related bloodstream infections. No significant difference was observed in the inflammatory profile according to the type of locking solution.

2020 Frank Stinchfield Award: Identifying who will fail following irrigation and debridement for prosthetic joint infection

AIMS

Failure of irrigation and debridement (I&D) for prosthetic joint infection (PJI) is influenced by numerous host, surgical, and pathogen-related factors. We aimed to develop and validate a practical, easy-to-use tool based on machine learning that may accurately predict outcome following I&D surgery taking into account the influence of numerous factors.

METHODS

This was an international, multicentre retrospective study of 1,174 revision total hip (THA) and knee arthroplasties (TKA) undergoing I&D for PJI between January 2005 and December 2017. PJI was defined using the Musculoskeletal Infection Society (MSIS) criteria. A total of 52 variables including demographics, comorbidities, and clinical and laboratory findings were evaluated using random forest machine learning analysis. The algorithm was then verified through cross-validation.

RESULTS

Of the 1,174 patients that were included in the study, 405 patients (34.5%) failed treatment. Using random forest analysis, an algorithm that provides the probability for failure for each specific patient was created. By order of importance, the ten most important variables associated with failure of I&D were serum CRP levels, positive blood cultures, indication for index arthroplasty other than osteoarthritis, not exchanging the modular components, use of immunosuppressive medication, late acute (haematogenous) infections, methicillin-resistant Staphylococcus aureus infection, overlying skin infection, polymicrobial infection, and older age. The algorithm had good discriminatory capability (area under the curve = 0.74). Cross-validation showed similar probabilities comparing predicted and observed failures indicating high accuracy of the model.

CONCLUSION

This is the first study in the orthopaedic literature to use machine learning as a tool for predicting outcomes following I&D surgery. The developed algorithm provides the medical profession with a tool that can be employed in clinical decision-making and improve patient care. Future studies should aid in further validating this tool on additional cohorts. Cite this article: Bone Joint J 2020;102-B(7 Supple B):11-19.

Personalized therapy approach for hospitalized patients with COVID-19

Hospitalized patients with COVID-19 experiencing respiratory symptoms have different complications (inflammatory, co-infection and thrombotic) that are identifiable by analytics patterns. Personalized treatment decisions decreased early mortality (OR 0.144, CI 0.03–0.686; p=0.015). Increasing age (OR 1.06; p=0.038) and therapeutic effort limitation (OR 9.684; p<0.001) were associated with higher mortality.

Usefulness of guideline recommendations for prognosis in patients with candidemia

We aimed to analyze whether the lack of inclusion of specific recommendations for the management of candidemia is an independent risk factor for early and overall mortality. Multicenter study of adult patients with candidemia in 13 hospitals. We assessed the proportion of patients on whom nine specific ESCMID and IDSA guidelines recommendations had been applied, and analyzed its impact on mortality. 455 episodes of candidemia were documented. Patients who died within the first 48 hours were excluded. Sixty-two percent of patients received an appropriate antifungal treatment. Either echinocandin or amphotericin B therapy were administered in 43% of patients presenting septic shock and in 71% of those with neutropenia. Sixty-one percent of patients with breakthrough candidemia underwent a change in antifungal drug class. Venous catheters were removed in 79% of cases. Follow-up blood cultures were performed in 72% of cases. Ophthalmoscopy and echocardiogram were performed in 48% and 50% of patients, respectively. Length of treatment was appropriate in 78% of cases. Early (2-7 days) and overall (2-30 days) mortality were 8% and 27.7%, respectively. Inclusion of less than 50% of the specific recommendations was independently associated with a higher early (HR = 7.02, 95% CI: 2.97-16.57; P < .001) and overall mortality (HR = 3.55, 95% CI: 2.24-5.64; P < .001). In conclusion, ESCMID and IDSA guideline recommendations were not performed on a significant number of patients. Lack of inclusion of these recommendations proved to be an independent risk factor for early and overall mortality.

Smell and Taste Dysfunction in COVID-19 Is Associated With Younger Age in Ambulatory Settings: A Multicenter Cross-Sectional Study

BACKGROUND AND OBJECTIVE

Since the initial anecdotal reports of coronavirus disease 2019 (COVID-19) from China, a growing number of studies have reported on smell and/or taste dysfunction (STD). Objective: The aim of our study was to investigate the frequency and severity of STD in COVID-19 patients and to evaluate the association with demographic characteristics, hospital admission, symptoms, comorbidities, and blood biomarkers.

METHODS

We performed a multicenter cross-sectional study on patients who were positive for SARS-CoV-2 (n=846) and controls (n=143) from 15 Spanish hospitals. Data on STD were collected prospectively using an in-person survey. The severity of STD was categorized using a visual analog scale. We analyzed time to onset, recovery rate, time to recovery, hospital admission, pneumonia, comorbidities, smoking, and symptoms.

RESULTS

STD was at least 2-fold more common in COVID-19-positive patients than in controls. COVID-19-positive hospitalized patients were older, with a lower frequency of STD, and recovered earlier than outpatients. Analysis stratified by severity of STD showed that more than half of COVID-19 patients presented severe loss of smell (53.7%) or taste (52.2%); both senses were impaired in >90%. In the multivariate analysis, older age (>60 years), being hospitalized, and increased C-reactive protein were associated with a better sense of smell and/or taste. COVID-19-positive patients reported improvement in smell (45.6%) and taste (46.1%) at the time of the survey; in 90.6% this was within 2 weeks of infection.

CONCLUSION

STD is a common symptom in COVID-19 and presents mainly in young and nonhospitalized patients. More studies are needed to evaluate follow-up of chemosensory impairment.

Lower Success Rate of Débridement and Implant Retention in Late Acute versus Early Acute Periprosthetic Joint Infection Caused by Staphylococcus spp. Results from a Matched Cohort Study

BACKGROUND

Surgical débridement, antibiotics and implant retention (DAIR) is currently recommended by international guidelines for both early acute (postsurgical) and late acute (hematogenous) periprosthetic joint infections (PJIs). However, due to a different pathogenesis of infection, a different treatment strategy may be needed.

QUESTIONS/PURPOSES

(1) Compared with early acute PJIs, are late acute PJIs associated with a higher risk of DAIR failure? (2) When stratified by microorganism, is the higher risk of failure in late acute PJI associated with Staphylocococcus aureus infection? (3) When analyzing patients with S. aureus infection, what factors are independently associated with DAIR failure?

METHODS

In this multicenter observational study, early acute and late acute PJIs treated with DAIR were retrospectively evaluated and matched according to treating center, year of diagnosis, and infection-causing microorganism. If multiple matches were available, the early acute PJI diagnosed closest to the late acute PJI was selected. A total of 132 pairs were included. Treatment success was defined as a retained implant during follow-up without the need for antibiotic suppressive therapy.

RESULTS

Late acute PJIs had a lower treatment success (46% [60 of 132]) compared with early acute PJIs (76% [100 of 132]), OR 3.9 [95% CI 2.3 to 6.6]; p < 0.001), but the lower treatment success of late acute PJIs was only observed when caused by Staphylococcus spp (S. aureus: 34% versus 75%; p < 0.001; coagulase-negative staphylococci: 46% versus 88%; p = 0.013, respectively). On multivariable analysis, late acute PJI was the only independent factor associated with an unsuccessful DAIR when caused by S. aureus (OR 4.52 [95% CI 1.79 to 11.41]; p < 0.001).

CONCLUSIONS

Although DAIR seems to be a successful therapeutic strategy in the management of early acute PJI, its use in late acute PJI should be reconsidered when caused by Staphylococcus spp. Our results advocate the importance of isolating the causative microorganism before surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Value of multidetector computed tomography for the differentiation of delayed aseptic and septic complications after total hip arthroplasty

OBJECTIVE

The differentiation between delayed aseptic and septic complications of total hip arthroplasty is crucial to allow appropriate surgical planning and timely antimicrobial treatment. The aim of this study was to investigate the utility of multidetector computed tomography (CT) findings to diagnose aseptic mechanical loosening, granulomatous reaction, and periprosthetic joint infection in patients who underwent total hip arthroplasty before revision surgery.

MATERIALS AND METHODS

Ninety-six consecutive patients with a clinical suspicion of periprosthetic complications underwent revision surgery over an 8-year period. All patients had been evaluated preoperatively using multidetector CT without contrast media. Two blinded musculoskeletal radiologists reviewed multidetector CT images, including periprosthetic soft-tissue accumulation, prosthetic acetabular malposition, periprosthetic osteolysis, enlarged iliac lymph nodes, and heterotopic ossification. Risk factors for aseptic and septic loosening were identified using multivariate analysis.

RESULTS

Multidetector CT-related variables independently associated with periprosthetic joint infection were high periprosthetic soft-tissue accumulation, periprosthetic osteolysis without expansile periosteal reaction and enlarged iliac lymph nodes. On the other hand, the absence of the following radiological signs: low or high periprosthetic soft-tissue accumulation, mild or severe periprosthetic osteolysis, and enlarged iliac lymph nodes, were predictors of aseptic mechanical loosening. Low periprosthetic soft-tissue accumulation, severe periprosthetic osteolysis with expansile periosteal reaction, and mild acetabular malposition were significant variables associated with granulomatosis.

CONCLUSION

Multidetector CT findings are useful to differentiate between aseptic and septic complications before revision surgery. The presence of osteolysis with expansile periosteal reaction appeared to be a time-dependent variable.

When antibiotics fail: a clinical and microbiological perspective on antibiotic tolerance and persistence of Staphylococcus aureus

Staphylococcus aureus is a major human pathogen causing a vast array of infections with significant mortality. Its versatile physiology enables it to adapt to various environments. Specific physiological changes are thought to underlie the frequent failure of antimicrobial therapy despite susceptibility in standard microbiological assays. Bacteria capable of surviving high antibiotic concentrations despite having a genetically susceptible background are described as 'antibiotic tolerant'. In this review, we put current knowledge on environmental triggers and molecular mechanisms of increased antibiotic survival of S. aureus into its clinical context. We discuss animal and clinical evidence of its significance and outline strategies to overcome infections with antibiotic-tolerant S. aureus.

Recommendations of the Spanish Antibiogram Committee (COESANT) for selecting antimicrobial agents and concentrations for in vitro susceptibility studies using automated systems

Automated antimicrobial susceptibility testing devices are widely implemented in clinical microbiology laboratories in Spain, mainly using EUCAST (European Committee on Antimicrobial Susceptibility Testing) breakpoints. In 2007, a group of experts published recommendations for including antimicrobial agents and selecting concentrations in these systems. Under the patronage of the Spanish Antibiogram Committee (Comité Español del Antibiograma, COESANT) and the Study Group on Mechanisms of Action and Resistance to Antimicrobial Agents (GEMARA) from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), and aligned with the Spanish National Plan against Antimicrobial Resistance (PRAN), a group of experts have updated this document. The main modifications from the previous version comprise the inclusion of new antimicrobial agents, adaptation of the ranges of concentrations to cover the EUCAST breakpoints and epidemiological cut-off values (ECOFFs), and the inference of new resistance mechanisms. This proposal should be considered by different manufacturers and users when designing new panels or cards. In addition, recommendations for selective reporting are also included. With this approach, the implementation of EUCAST breakpoints will be easier, increasing the quality of antimicrobial susceptibility testing data and their microbiological interpretation. It will also benefit epidemiological surveillance studies as well as the clinical use of antimicrobials aligned with antimicrobial stewardship programs.

Ceftaroline for severe community-acquired pneumonia: A real-world two-centre experience in Italy and Spain

BACKGROUND

Ceftaroline is one of latest additions to the armamentarium for treating community-acquired pneumonia (CAP). This study aimed to describe the outcome of severe CAP (SCAP) in a cohort of hospitalised patients treated with ceftaroline.

METHODS

A retrospective, observational study of patients with SCAP treated with ceftaroline in two hospitals in Spain and Italy. The primary objective was to explore 30-day mortality after diagnosis of SCAP.

RESULTS

During the study period the following were observed: there were 89 cases of SCAP treated with ceftaroline and 53 cases used in combination with other antibiotics (60%). Overall, 30-day mortality and clinical failure were 20% (18 of 89) and 36% (32 of 89), respectively. Independent predictors of 30-day mortality were: increasing age (OR for 1 year increase 1.0, 95% CI 1.0-1.1, P 0.043), presence of solid neoplasm (OR 4.0, 95% CI 1.0-15.1, P 0.044) and concomitant therapy with oseltamivir (OR 8.5, 95% CI 1.2°57.3, P 0.029). The only independent predictor of clinical failure was the time elapsing from SCAP diagnosis to ceftaroline therapy (OR for each passing day 1.5, 95% CI 1.1-1.9, P 0.003). The clinical success rate was 64% (57 of 89). In the subgroups of patients with proven Streptococcus pneumoniae, methicillin-susceptible Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) infection, clinical success was 83% (10 of 12), 75% (three of four) and 56% (five of nine), respectively.

CONCLUSIONS

Considering its spectrum of activity, ceftaroline could represent an important therapeutic option for SCAP. Further studies are needed to identify the precise clinical success rate against MRSA in a larger cohort of patients with SCAP.

Suppressive antibiotic therapy in prosthetic joint infections: a multicentre cohort study

OBJECTIVES

The aim was to describe the effectiveness of suppressive antibiotic treatment (SAT) in routine clinical practice when used in situations in which removal of a prosthetic implant is considered essential for the eradication of an infection, and it cannot be performed.

METHODS

This was a descriptive retrospective and multicentre cohort study of prosthetic joint infection (PJI) cases managed with SAT. SAT was considered to have failed if a fistula appeared or persisted, if debridement was necessary, if the prosthesis was removed due to persistence of the infection or if uncontrolled symptoms were present.

RESULTS

In total, 302 patients were analysed. Two hundred and three of these patients (67.2%) received monotherapy. The most commonly used drugs were tetracyclines (39.7% of patients) (120/302) and cotrimoxazole (35.4% of patients) (107/302). SAT was considered successful in 58.6% (177/302) of the patients (median time administered, 36.5 months; IQR 20.75-59.25). Infection was controlled in 50% of patients at 5 years according to Kaplan-Meier analysis. Resistance development was documented in 15 of 65 (23.1%) of the microbiologically documented cases. SAT failure was associated with age <70 years (sub-hazard ratio (SHR) 1.61, 95% CI 1.1-2.33), aetiology other than Gram-positive cocci (SHR 1.56, 95% CI 1.09-2.27) and location of the prosthesis in the upper limb (SHR 2.4, 95% CI 1.5-3.84). SAT suspension was necessary due to adverse effects in 17 of 302 patients (5.6%).

CONCLUSIONS

SAT offers acceptable results for patients with PJI when surgical treatment is not performed or when it fails to eradicate the infection.

The role of dalbavancin in the treatment of acute bacterial skin and skin structure infections (ABSSSIs)

Introduction: Acute bacterial skin and skin-structure infections (ABSSSI) are a subgroup of skin and soft tissue infections and are a common source of morbidity in both the community and the hospital setting. The most common cause of ABSSSI is Staphylococcus aureus, which also includes methicillin-resistant S. aureus (MRSA), together with beta-hemolytic streptococci, enterococci, and Gram-negative bacteria. Since the emergence of MRSA, the management of ABSSSI has become more challenging. Novel therapies alternative to teicoplanin and vancomycin, intravenous agents commonly used against MRSA and employed in hospitalized patients, and to other antibiotics which are used as standard of care for MRSA infection, with a higher efficacy and safer profile are worth evaluating.Areas covered: This review presents and discusses current evidence on the use of dalbavancin in the treatment of ABSSSI.Expert opinion: Dalbavancin represents a promising therapeutic choice in patients with ABSSSI, thanks to its favorable pharmacokinetic profile, valuable antimicrobial spectrum, and good safety profile.

Prosthetic joint infection by Bordetella holmesii: Case report and a review of the literature

INTRODUCTION

Bordetella holmesii is a Gram-negative coccobacillus involved in different infections mostly described in case reports. Prosthetic joint infections in relation to this pathogen are rare. Here, we present the third case of B. holmesii in a patient without anatomical or functional spleen dysfunction.

CASE REPORT

The patient was a 62-year-old female with a total knee prosthesis implanted in 1997 that required multiple replacements of the femoral component due to aseptic loosening in the past years. The patient was admitted to our hospital for an elective replacement surgery due to new radiological signs of loosening. B. holmesii was isolated from synovial fluid obtained during surgery. The identification was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and confirmed by 16S rRNA gene amplification and sequencing. Antibiotic treatment was started but 14 days after surgery the patient presented pain and joint effusion. An arthrocentesis was performed and synovial fluid culture was positive again for B. holmesii. Surgical debridement including polyethylene replacement was performed and antibiotic treatment was continued for 3 months. After a 2-year follow-up period, the patient remained asymptomatic and physical examination showed normal function of the prosthesis.

CONCLUSION

B. holmesii is an uncommon cause of bone and joint infections. This case indicates that this microorganism is a potential pathogen of prosthetic or native arthritis, and it should be considered when cultures are negative and in cases presenting torpid evolution.