Pre-engraftment bacteremia after allogeneic hematopoietic cell transplantation without primary fluoroquinolone antibacterial prophylaxis.

BACKGROUND: Bacteremia is a common complication in allogeneic hematopoietic cell transplant recipients (alloHCTr), especially during the pre-engraftment period. International guidelines recommend antibacterial prophylaxis (ABP), despite potential selection for multidrug-resistant organisms (MDRO). Limited contemporary data exist on the epidemiology of pre-engraftment bacteremia in alloHCTr, who do not receive ABP. METHODS: We performed a retrospective observational single-center cohort study including all consecutive adult alloHCTr (2015-2021), investigating the incidence, risk factors, and outcomes of bacteremia during the engraftment period. Primary fluoroquinolone (FQ) ABP is not routinely administered in our center. RESULTS: Among 421 patients identified, 124 bacteremia episodes were observed in 121/421 (29%) alloHCTr. The median time to the 1st bacteremia episode was 9 days (IQR 6-11). Most (105/124, 85%) episodes were monomicrobial, while >1 pathogens were identified in 19/124 (15%) episodes. Overall, 152 pathogens were isolated, with a predominance of Gram-positive (118/152, 78%), including coagulase-negative staphylococci (n:47), streptococci (n:46), and enterococci (n:15), followed by Gram-negative bacteria (GNB, 30/152, 20%), and anaerobes (4/152, 3%). There were 2/152 (1%) MDRO (extended-spectrum beta-lactamase producing) GNB. Multivariable analyses identified age >40-year-old (OR 2.4, P = 0.02), male gender (OR 1.8, P = 0.02), and a haploidentical/mismatched unrelated donor (OR 2.5, P < 0.001) as independent risk factors for bacteremia. All cause 30-day mortality among alloHCTr with bacteremia was 0.8% (1/121): one patient died due to an HCT-related complication. CONCLUSION: Despite lack of primary FQ ABP, low rates of bacteremia were observed during the pre-engraftment period, with low MDRO prevalence and mortality. Our findings may allow to revisit the need for primary universal FQ ABP in high-risk neutropenic hematology patients.

RAC2 gain-of-function variants causing inborn error of immunity drive NLRP3 inflammasome activation.

A growing number of patients presenting severe combined immunodeficiencies attributed to monoallelic RAC2 variants have been identified. The expression of the RHO GTPase RAC2 is restricted to the hematopoietic lineage. RAC2 variants have been described to cause immunodeficiencies associated with high frequency of infection, leukopenia, and autoinflammatory features. Here, we show that specific RAC2 activating mutations induce the NLRP3 inflammasome activation leading to the secretion of IL-1ß and IL-18 from macrophages. This activation depends on the activation state of the RAC2 variant and is mediated by the downstream kinase PAK1. Inhibiting the RAC2-PAK1-NLRP3 inflammasome pathway might be considered as a potential treatment for these patients.

What Place Is There for Long-Acting Antibiotics in the Management of Gram-Positive Infections? A Qualitative Cross-Sectional Study.

OBJECTIVES: To identify the current practices with long half-life lipoglycopeptides (LGPs) and potential use/position of oritavancin. RESULTS: Despite their indication being limited to skin and soft tissue infections (SSTIs), long half-life lipoglycopeptides are mainly used off-label to treat bone and joint infections (BJIs) and infective endocarditis. Oritavancin and dalbavancin are both semisynthetic lipoglycopeptide antibiotics with activity against Gram-positive organisms. The game-changing property of these two antibiotics is their one-time dosing. Due to its shorter half-life, oritavancin might have an advantage over dalbavancin for a treatment duration of less than 2 weeks, as it could be used both in prolonged treatments of complicated patients in BJIs or administered as a single-dose treatment for Gram-positive cocci infections usually treated by a 5- to 10-day antibiotic course. These infections include urinary tract infections, bacteremias, catheter-related infections, etc. In addition to the possibility of being used as an end-of-treatment injection, oritavancin could be used as an empiric therapy treatment in the postoperative period in the context of device-associated especially prosthetic joint infections to allow for the early discharge of the patient. METHODS: A qualitative survey was conducted in March 2022 including sixteen infectiologists, one internist, five hospital pharmacists, and one pharmacologist. CONCLUSION: Long half-life lipoglycopeptides contribute to changing the paradigm in the management of acute bacterial infections, as infectiologists now consider a range of indications and patient profiles for one single drug. Oritavancin strengthens the therapeutic arsenal in numerous infections from BJIs to urinary tract infections and could help to manage specific clinical situations, on top of providing potential benefits for the hospital's budget.

Bacterial infections in solid organ transplant recipients.

PURPOSE OF REVIEW: Bacteria are the leading cause of infections in solid organ transplant (SOT) recipients, significantly impacting patient outcome. Recently detailed and comprehensive epidemiological data have been published. RECENT FINDING: This literature review aims to provide an overview of bacterial infections affecting different types of SOT recipients, emphasizing underlying risk factors and pathophysiological mechanisms. SUMMARY: Lung transplantation connects two microbiotas: one derived from the donor's lower respiratory tract with one from the recipient's upper respiratory tract. Similarly, liver transplantation involves a connection to the digestive tract and its microbiota through the bile ducts. For heart transplant recipients, specific factors are related to the management strategies for end-stage heart failure based with different circulatory support tools. Kidney and kidney-pancreas transplant recipients commonly experience asymptomatic bacteriuria, but recent studies have suggested the absence of benefice of routine treatment. Bloodstream infections (BSI) are frequent and affect all SOT recipients. Nonorgan-related risk factors as age, comorbidity index score, and leukopenia contribute to BSI development. Bacterial opportunistic infections have become rare in the presence of efficient prophylaxis. Understanding the epidemiology, risk factors, and pathophysiology of bacterial infections in SOT recipients is crucial for effective management and improved patient outcomes.

Efficacy of an antimicrobial stewardship intervention for early adaptation of antibiotic therapy in high-risk neutropenic patients.

BACKGROUND: The 4th European Conference on Infections in Leukemia recommends early adaptation of empirical antibiotic therapy (EAT) for febrile neutropenia in stable patients. OBJECTIVES: To assess the efficacy of an antimicrobial stewardship (AMS) intervention promoting early de-escalation and discontinuation of EAT in high-risk neutropenic patients. METHODS: This before-after study was conducted in the hematology department of the University Hospital of Nice, France. The AMS intervention included the development of clinical decision support algorithms, a twice-weekly face-to-face review of all antibiotic prescriptions and monthly feedback on the intervention. The primary endpoint was overall antibiotic consumption during hospital stay, expressed as days of therapy (DOT). RESULTS: A total of 113 admissions were included: 56 during the pre-intervention period and 57 during the intervention period. Induction chemotherapy and conditioning for allogeneic stem cell transplantation were the most frequent reasons for admission. In the intervention period, there was a significant decrease in overall antibiotic consumption (median DOT 20 vs. 28 days, p = 0.006), carbapenem consumption (median DOT 5.5 vs. 9 days, p = 0.017) and anti-resistant Gram-positive agents consumption (median DOT 8 vs. 11.5 days, p = 0.017). We found no statistical difference in the rates of intensive care unit admission (9% in each period) and 30-day mortality (5% vs. 0%, p = 0.243). Compliance with de-escalation and discontinuation strategies was significantly higher in the intervention period (77% vs. 8%, p < 0.001). CONCLUSION: A multifaceted AMS intervention led to high compliance with early de-escalation and discontinuation of EAT and lower overall antibiotic consumption, without negatively affecting clinical outcomes.

Hepatitis E Virus Infection Epidemiology in Recipients of Allogeneic Hematopoietic Cell Transplant.

Among 292 recipients of allogeneic hematopoietic cell transplant (2018-2022), 64 (21.9%) tested positive for anti-hepatitis E virus (HEV) immunoglobulin G. Among 208 recipients tested by plasma/serum HEV polymerase chain reaction (2012-2022), 3 (1.4%) primary HEV infections were diagnosed; in 1 patient, plasma HEV polymerase chain reaction relapsed positive for 100 days. HEV infection remains rare albeit associated with persistent viral replication.

Effectiveness and safety of dalbavancin in France: a prospective, multicentre cohort study.

OBJECTIVES: Dalbavancin is a lipoglycopeptide antibiotic approved for the treatment of acute bacterial skin and skin structure infections. However, several studies have suggested that it is used mostly for off-label indications. We aimed to describe the use of dalbavancin in patients who received at least one dose of the antibiotic in France. METHODS: Prospective, observational, multicentre study conducted in France from September 2018 to April 2020. The primary outcome was the clinical response at 30 days after the last dalbavancin dose. RESULTS: A total of 151 patients in 16 centres were included in this study. The main infection sites were bone and joint infections (55.0%), multisite infections (15.9%), and vascular infections (14.6%), and the primary pathogens were coagulase-negative staphylococci (N = 82), Staphylococcus aureus (N = 51), and enterococci (N = 27). Most patients (71.5%) received three previous antibiotic treatments. The number of dalbavancin injections per patient was 1 in 26 patients (17.2%), 2 in 95 patients (62.9%), 3 in 17 patients (11.3%), and more than 3 in 13 patients (8.6%), with a mean cumulative dose of 3089 ± 1461 mg per patient. Among the 129 patients with a complete follow-up, clinical success was achieved in 119 patients (92.2%). At least 1 adverse event was reported in 67 patients (44.4%), including 12 (7.9%) patients with dalbavancin-related adverse events. CONCLUSIONS: The results of the study showed that dalbavancin is used mostly for off-label indications and in heavily pretreated patients in France. The clinical response at 30 days after the last dose was favourable in most patients, with a good safety profile.

Time-to-detection in culture of Mycobacterium tuberculosis: performance for assessing index cases contact-positivity.

OBJECTIVES: Time-to-detection (TTD) in culture on liquid media is inversely correlated to bacillary load and should be a contributing factor for assessing tuberculosis transmission. We wanted to assess if TTD was a better alternative than smear status to estimate transmission risk. METHODS: From October 2015 to June 2022, we retrospectively studied a cohort of index cases (IC) with pulmonary tuberculosis (tuberculosis disease [TD]) from which samples were culture-positive before treatment. We studied the correlation between TTD and contact-positivity (CP) of IC contacts: CP was defined as CP = 1 (CP group) in case of TD or latent tuberculosis infection (LTI) in at least one screened contact of an IC, and CP = 0 otherwise (contact-negativity [CN] group). Univariate and multivariable analyses (logistic regression) were done. RESULTS: Of the 185 IC, 122 were included, generating 846 contact cases of which 705 were assessed. A transmission event (LTI or TD) was identified in 193 contact cases (transmission rate: 27%). At day 9, 66% and 35% of the IC had their sample positive in culture for CP and CN groups, respectively. Age and TTD ≤9 days were independent criteria of CP (odds ratio 0.97, confidence interval [0.95-0.98], P = 0.002 and odds ratio 3.52, confidence interval [1.59-7.83], P = 0.001, respectively). CONCLUSION: TTD was a more discriminating parameter than smear status to evaluate the transmission risk of an IC with pulmonary tuberculosis. Therefore, TTD should be considered in the contact-screening strategy around an IC.

Breakthrough infections due to SARS-CoV-2 Delta variant: relation to humoral and cellular vaccine responses.

Introduction: COVID-19 vaccines are expected to provide effective protection. However, emerging strains can cause breakthrough infection in vaccinated individuals. The immune response of vaccinated individuals who have experienced breakthrough infection is still poorly understood. Methods: Here, we studied the humoral and cellular immune responses of fully vaccinated individuals who subsequently experienced breakthrough infection due to the Delta variant of SARS-CoV-2 and correlated them with the severity of the disease. Results: In this study, an effective humoral response alone was not sufficient to induce effective immune protection against severe breakthrough infection, which also required effective cell-mediated immunity to SARS-CoV-2. Patients who did not require oxygen had significantly higher specific (p=0.021) and nonspecific (p=0.004) cellular responses to SARS-CoV-2 at the onset of infection than those who progressed to a severe form. Discussion: Knowing both humoral and cellular immune response could allow to adapt preventive strategy, by better selecting patients who would benefit from additional vaccine boosters. Trial registration numbers: https://clinicaltrials.gov, identifier NCT04355351; https://clinicaltrials.gov, identifier NCT04429594.

Lesson from the COVID-19 pandemic lockdown: A major change of hospital-diagnosed bacteremia epidemiology.

OBJECTIVES: When the COVID-19 pandemic reached France early in 2020, the enforced nationwide lockdown deeply altered lifestyle as well as hospital processes and modalities of care. The aim of the study was to evaluate the impact during the lockdown of the first epidemic wave on the epidemiology of bacteremia in one French University Hospital. PATIENTS AND METHODS: Retrospective cohort study including adult patients with positive blood culture between 23rd March to 24th May 2020. The clinical-microbiological characteristics were compared with those of the period from 25th March to 26th May 2019. The data were adjusted to the number of hospitalizations (h). RESULTS: In 2020, 189 bacteremia were diagnosed from 1939 vials (9658 hospitalizations, 10911 emergency room consultations) compared to 143 from 1976 vials (14797 hospitalizations, 16493 emergency room consultations) recorded in 2019. The incidence of bacteremia increased up to 19.7 per 1000h in 2020 vs 9.7 in 2019 (p < 0.001). The main differences (2020 vs 2019) were: Staphylococcus aureus bacteremia (2.4 vs 1.0/1000h, p = 0.012), polymicrobial bacteremia (2.2 vs 0.9/1000h p = 0.013) and Gram-negative bacteremia (8.9 vs 4.3/1000h, p < 0.01). Conversely, Streptococcus pneumoniae incidence decreased (0 vs 0.47/1000h, p = 0.047). The standardized incidence ratio calculation confirmed these results. CONCLUSION: The lockdown and the impact of the first wave of the Covid-19 pandemic on the health system resulted in increased hospital-diagnosed bacteremia and decreased pneumococcal bacteremia. Disruption and overload of ICUs, lockdown with preventive control measures, and decrease in human-to-human interaction may have been the main reasons.

MPox virus: an unusual aetiology of peritonitis.

We describe a rare case of severe disseminated monkeypox (MPox) virus infection complicated by peritonitis in a 44-year-old man living with well-controlled HIV. The patient was successfully treated with tecovirimat without requiring surgery. MPox should be considered in the differential diagnosis of non-bacterial peritonitis in patients at risk of infection.

Accurate Detection of SARS-CoV-2 by Next-Generation Sequencing in Low Viral Load Specimens.

As new SARS-CoV-2 variants emerge, there is an urgent need to increase the efficiency and availability of viral genome sequencing, notably to detect the lineage in samples with a low viral load. SARS-CoV-2 genome next-generation sequencing (NGS) was performed retrospectively in a single center on 175 positive samples from individuals. An automated workflow used the Ion AmpliSeq SARS-CoV-2 Insight Research Assay on the Genexus Sequencer. All samples were collected in the metropolitan area of the city of Nice (France) over a period of 32 weeks (from 19 July 2021 to 11 February 2022). In total, 76% of cases were identified with a low viral load (Ct ≥ 32, and ≤200 copies/µL). The NGS analysis was successful in 91% of cases, among which 57% of cases harbored the Delta variant, and 34% the Omicron BA.1.1 variant. Only 9% of cases had unreadable sequences. There was no significant difference in the viral load in patients infected with the Omicron variant compared to the Delta variant (Ct values, p = 0.0507; copy number, p = 0.252). We show that the NGS analysis of the SARS-CoV-2 genome provides reliable detection of the Delta and Omicron SARS-CoV-2 variants in low viral load samples.

Efficacy and safety of anakinra in adults presenting deteriorating respiratory symptoms from COVID-19: A randomized controlled trial.

OBJECTIVE: We aimed to investigate whether anakinra, an interleukin-1receptor inhibitor, could improve outcome in moderate COVID-19 patients. METHODS: In this controlled, open-label trial, we enrolled adults with COVID-19 requiring oxygen. We randomly assigned patients to receive intravenous anakinra plus optimized standard of care (oSOC) vs. oSOC alone. The primary outcome was treatment success at day 14 defined as patient alive and not requiring mechanical ventilation or extracorporeal membrane oxygenation. RESULTS: Between 27th April and 6th October 2020, we enrolled 71 patients (240 patients planned to been enrolled): 37 were assigned to the anakinra group and 34 to oSOC group. The study ended prematurely by recommendation of the data and safety monitoring board due to safety concerns. On day 14, the proportion of treatment success was significantly lower in the anakinra group 70% (n = 26) vs. 91% (n = 31) in the oSOC group: risk difference-21 percentage points (95% CI, -39 to -2), odds ratio 0.23 (95% CI, 0.06 to 0.91), p = 0.027. After a 28-day follow-up, 9 patients in the anakinra group and 3 in the oSOC group had died. Overall survival at day 28 was 75% (95% CI, 62% to 91%) in the anakinra group versus 91% (95% CI, 82% to 100%) (p = 0.06) in the oSOC group. Serious adverse events occurred in 19 (51%) patients in the anakinra group and 18 (53%) in the oSOC group (p = 0·89). CONCLUSION: This trial did not show efficacy of anakinra in patients with COVID-19. Furthermore, contrary to our hypothesis, we found that anakinra was inferior to oSOC in patients with moderate COVID-19 pneumonia.

Clindamycin Efficacy for Cutibacterium acnes Shoulder Device-Related Infections.

Clindamycin is an antibiotic with high bioavailability and appropriate bone diffusion, often proposed as an alternative in guidelines for C. acnes prosthetic joint infections. We aimed to evaluate the efficacy of clindamycin in the treatment of C. acnes shoulder implant joint infections (SIJI). METHODS: A retrospective analysis was conducted at the University Hospital of Nice (France) between 2010 and 2019. We included patients with one shoulder implant surgical procedure and at least one C. acnes positive sample. We selected the C. acnes SIJI according to French and international recommendations. The primary endpoint was favorable outcome of C. acnes SIJI treatment after at least 1-year follow-up in the clindamycin group compared to another therapeutic group. RESULTS: Forty-eight SIJI were identified and 33 were treated with clindamycin, among which 25 were treated with monotherapy. The median duration of clindamycin antibiotherapy was 6 weeks. The average follow-up was 45 months; one patient was lost to follow-up. Twenty-seven patients out of 33 (82%) were cured with clindamycin, compared to 9/12 (75%) with other antibiotics. The rate of favorable outcomes increased to 27/31 (87%) with clindamycin and to 9/10 (90%) for other antibiotics when no septic revision strategies were excluded (P = 1.00). CONCLUSIONS: The therapeutic strategy based on one- or two-stage revision associated with 6 weeks of clindamycin seems to be effective.

Obesity, diabetes, hypertension and severe outcomes among inpatients with coronavirus disease 2019: a nationwide study.

OBJECTIVES: Initial studies of individuals with coronavirus disease 2019 (COVID-19) revealed that obesity, diabetes and hypertension were associated with severe outcomes. Subsequently, some authors showed that the risk could vary according to age, gender, co-morbidities and medical history. In a nationwide retrospective cohort, we studied the association between these co-morbidities and patients' requirement for invasive mechanical ventilation (IMV) or their death. METHODS: All French adult inpatients with COVID-19 admitted during the first epidemic wave (February to September 2020) were included. When patients were diagnosed with obesity, diabetes or hypertension for the first time in 2020, these conditions were considered as incident co-morbidities, otherwise they were considered prevalent. We compared outcomes of IMV and in-hospital death according to obesity, diabetes and hypertension, taking age, gender and Charlson's co-morbidity index score (CCIS) into account. RESULTS: A total of 134 209 adult inpatients with COVID-19 were included, half of them had hypertension (n = 66 613, 49.6%), one in four were diabetic (n = 32 209, 24.0%), and one in four were obese (n = 32 070, 23.9%). Among this cohort, IMV was required for 13 596 inpatients, and 19 969 patients died. IMV and death were more frequent in male patients (adjusted oods ratio (aOR) 2.0, 95% CI 1.9-2.1 and aOR 1.5, 95% CI 1.4-1.5, respectively), IMV in patients with co-morbidities (aOR 2.1, 95% CI 2.0-2.2 for CCIS = 2 and aOR 3.0, 95% CI 2.8-3.1 for CCIS ≥5), and death in patients aged 80 or above (aOR 17.0, 95% CI 15.5-18.6). Adjusted on age, gender and CCIS, death was more frequent among inpatients with obesity (aOR 1.2, 95% CI 1.1-1.2) and diabetes (aOR 1.2, 95% CI 1.1-1.2). IMV was more frequently necessary for inpatients with obesity (aOR 1.9, 95% CI 1.8-2.0), diabetes (aOR 1.4, 95% CI 1.3-1.4) and hypertension (aOR 1.7, 95% CI 1.6-1.8). Comparatively, IMV was more often required for patients with the following incident co-morbidities: obesity (aOR 3.5, 95% CI 3.3-3.7), diabetes (aOR 2.0, 95% CI 1.8-2.1) and hypertension (aOR 2.5, 95% CI 2.4-2.6). CONCLUSIONS: Among 134 209 inpatients with COVID-19, mortality was more frequent among patients with obesity and diabetes. IMV was more frequently necessary for inpatients with obesity, diabetes and hypertension. Patients for whom these were incident co-morbidities were particularly at risk. Specific medical monitoring and vaccination should be priorities for patients with these co-morbidities.

COVID-19 patients age, comorbidity profiles and clinical presentation related to the SARS-CoV-2 UK-variant spread in the Southeast of France.

The variant 20I/501Y.V1, associated to a higher risk of transmissibility, emerged in Nice city (Southeast of France, French Riviera) during January 2021. The pandemic has resumed late December 2020 in this area. A high incidence rate together with a fast turn-over of the main circulating variants, provided us the opportunity to analyze modifications in clinical profile and outcome traits. We performed an observational study in the University hospital of Nice from December 2020 to February 2021. We analyzed data of sequencing of SARS-CoV-2 from the sewage collector and PCR screening from all positive samples at the hospital. Then, we described the characteristics of all COVID-19 patients admitted in the emergency department (ED) (n = 1247) and those hospitalized in the infectious diseases ward or ICU (n = 232). The UK-variant was absent in this area in December, then increasingly spread in January representing 59% of the PCR screening performed mid-February. The rate of patients over 65 years admitted to the ED decreased from 63 to 50% (p = 0.001). The mean age of hospitalized patients in the infectious diseases ward decreased from 70.7 to 59.2 (p < 0.001) while the proportion of patients without comorbidity increased from 16 to 42% (p = 0.007). Spread of the UK-variant in the Southeast of France affects younger and healthier patients.

Management of prosthetic joint infections in France: a national audit to identify key situations requiring innovation and homogenization.

BACKGROUND: Prosthetic joint infections (PJI) are one of the most serious complication of arthroplasty. The management of PJI needs a multidisciplinary collaboration between orthopaedic surgeon, infectious disease specialist and microbiologist. In France, the management of PJI is organized around reference centres (CRIOACs). Our main objective was to perform an audit through a questionnaire survey based on clinical cases, to evaluate how French physicians manage PJI. Eligible participants were all physicians involved in care of patients presenting a PJI. Physicians could answer individually, or collectively during a multidisciplinary team meeting dedicated to PJI. The survey consisted as three questionnaires organized in a total of six clinical cases. RESULTS: Answers from the CRIOACs to the three questionnaires were 92, 77, and 53%. Between 32 and 39% of respondents did not administer antibiotic prophylaxis despite positive S. aureus pre-operative documentation. One-stage exchange strategy was widely preferred in all clinical cases, with no difference between CRIOACs and other centres. Rifampicin was prescribed for S. aureus PJI, in a situation with (90-92%) or without any prosthesis (70%). There was no consensus for the total antibiotic regimen duration, with prescriptions from six to 12 weeks for a majority of respondents. CONCLUSIONS: Surgical strategy for the management of PJI was homogenous with a preference for a one-stage exchange strategy. Medical management was more heterogenous, which reflects the heterogeneity of those infections and difficulties to perform studies with strong conclusions.