An Outpatient Clinic as a Potential Site of Transmission for an Outbreak of New Delhi Metallo-ß-Lactamase-producing Klebsiella pneumoniae Sequence Type 716: A Study Using Whole-genome Sequencing.

BACKGROUND: The incidence of nosocomial infections due to carbapenem-resistant Klebsiella pneumoniae is increasing worldwide. Whole-genome sequencing (WGS) can help elucidate the transmission route of nosocomial pathogens. METHODS: We combined WGS and epidemiological data to analyze an outbreak of New Delhi metallo-ß-lactamase (NDM)-producing K. pneumoniae that occurred in 2 Belgian hospitals situated about 50 miles apart. We characterized 74 NDM-producing K. pneumoniae isolates (9 from hospital A, 24 from hospital B, and 41 contemporary isolates from 15 other Belgian hospitals) using pulsed-field gel electrophoresis and WGS. RESULTS: A K. pneumoniae sequence type 716 clone was identified as being responsible for the outbreak with all 9 strains from hospital A and 20 of 24 from hospital B sharing a unique pulsotype and being clustered together at WGS (compared with 1 of 41 isolates from other Belgian hospitals). We identified the outpatient clinic of hospital B as the probable bridging site between the hospitals after combining epidemiological, phylogenetic, and resistome data. We also identified the patient who probably caused the transmission. In fact, all but 1 strain from hospital A carried a Tn1331-like transposon, whereas none of the hospital B isolates did. The patient from hospital A who did not have the Tn1331-like transposon was treated at the outpatient clinic of hospital B on the same day as the first NDM-producing K. pneumoniae-positive patient from hospital B. CONCLUSIONS: The results from our WGS-guided investigation highlight the importance of implementing adequate infection control measures in outpatient settings, especially when healthcare delivery moves from acute care facilities to outpatient clinics.

Genetic characteristics and antimicrobial resistance of Staphylococcus epidermidis isolates from patients with catheter-related bloodstream infections and from colonized healthcare workers in a Belgian hospital.

BACKGROUND: Staphylococcus epidermidis is a pathogen that is frequently encountered in the hospital environment. Healthcare workers (HCWs) can serve as a reservoir for the transmission of S. epidermidis to patients. METHODS: The aim of this study was to compare and identify differences between S. epidermidis isolated from 20 patients with catheter-related bloodstream infections (CRBSIs) and from the hands of 42 HCWs in the same hospital in terms of antimicrobial resistance, biofilm production, presence of the intercellular adhesion (ica) operon and genetic diversity (pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and staphylococcal cassette chromosome (SCC) mec typing). RESULTS: S. epidermidis isolates that caused CRBSI were resistant to significantly more non-betalactam drugs than were isolates collected from HCWs. Among the 43 mecA positive isolates (26 from HCWs), the most frequent SCCmec type was type IV (44%). The ica operon was significantly more prevalent in CRBSI isolates than in HCWs (P < 0.05). Weak in vitro biofilm production seemed to correlate with the absence of the ica operon regardless of the commensal or pathogenic origin of the isolate. The 62 isolates showed high diversity in their PFGE patterns divided into 37 different types: 19 harbored only by the CRBSI isolates and 6 shared by the clinical and HCW isolates. MLST revealed a total of ten different sequence types (ST). ST2 was limited to CRBSI-specific PFGE types while the "mixed" PFGE types were ST5, ST16, ST88 and ST153. CONCLUSION: One third of CRBSI episodes were due to isolates belonging to PFGE types that were also found on the hands of HCWs, suggesting that HCW serve as a reservoir for oxacillin resistance and transmission to patients. However, S. epidermidis ST2, mecA-positive and icaA-positive isolates, which caused the majority of clinically severe CRBSI, were not recovered from the HCW's hands.

The Acquisition of Multidrug-Resistant Bacteria in Patients Admitted to COVID-19 Intensive Care Units: A Monocentric Retrospective Case Control Study.

Whether the risk of multidrug-resistant bacteria (MDRB) acquisition in the intensive care unit (ICU) is modified by the COVID-19 crisis is unknown. In this single center case control study, we measured the rate of MDRB acquisition in patients admitted in COVID-19 ICU and compared it with patients admitted in the same ICU for subarachnoid hemorrhage (controls) matched 1:1 on length of ICU stay and mechanical ventilation. All patients were systematically and repeatedly screened for MDRB carriage. We compared the rate of MDRB acquisition in COVID-19 patients and in control using a competing risk analysis. Of note, although we tried to match COVID-19 patients with septic shock patients, we were unable due to the longer stay of COVID-19 patients. Among 72 patients admitted to the COVID-19 ICUs, 33% acquired 31 MDRB during ICU stay. The incidence density of MDRB acquisition was 30/1000 patient days. Antimicrobial therapy and exposure time were associated with higher rate of MDRB acquisition. Among the 72 SAH patients, 21% acquired MDRB, with an incidence density was 18/1000 patient days. The septic patients had more comorbidities and a greater number of previous hospitalizations than the COVID-19 patients. The incidence density of MDRB acquisition was 30/1000 patient days. The association between COVID-19 and MDRB acquisition (compared to control) risk did not reach statistical significance in the multivariable competing risk analysis (sHR 1.71 (CI 95% 0.93-3.21)). Thus, we conclude that, despite strong physical isolation, acquisition rate of MDRB in ICU patients was at least similar during the COVID-19 first wave compared to previous period.

Evaluation of the cost and length of hospital stays related to the management of an intestinal Clostridium difficile infection.

INTRODUCTION: Intestinal Clostridium difficile Infection (CDI) treated in hospitals may concern patients whose reason for admission is CDI (primary diagnosis) or who have acquired CDI during their stay (secondary diagnosis). OBJECTIVES: The objective of this study is to evaluate the cost for social security and hospitals and the length of hospital stays related to CDIs as the main reason for admission. METHOD: This study was carried out in 2012 in 13 Belgian hospitals. Cases were selected by using diagnosis recorded in minimum discharge summaries. Pediatric stays are not part of the inclusion criteria (n= 86). RESULTS: The average length of stay (standard deviation) was 13.53 days (11.95). The average cost (standard deviation) covered by social security/hospitals was €5,019.51 / €6,286.39 (9,638.42/ 6,368.45). 7% of patients were admitted to the Intensive Care Unit during hospitalization, for an average duration (standard deviation) of 8.18 days (2.93). The mortality rate was 8.1%. 19.8% of patients used vancomycin during the stay, 43% were treated with metronidazole only, 12.8% used vancomycin and metronidazole and 24.4% do not received vancomycin or metronidazole. No patients received fidaxomycin. CONCLUSION: This study made it possible to approach the cost of CDI as the main reason for admission. Such data should allow contributing to optimally assess both the pharmacoeconomic impact of the implementation of prevention strategies and also therapeutic management making use of more expensive medicinal products but associated with decreased risk of recurrence.

[Study of the prevalence of nosocomial infections and associated factors in the two university hospitals of Lubumbashi, Democratic Republic of Congo]. / Etude de la prévalence des infections nosocomiales et des facteurs associes dans les deux hopitaux universitaires de Lubumbashi, République Démocratique du Congo: cas des Cliniques Universitaires de Lubumbashi et l'Hôpital Janson Sendwe.

INTRODUCTION: To estimate the prevalence "on any given day" of nosocomial infections and to determine their associated factors. Then, to estimate the prevalence of microorganisms responsible for nosocomial infections in Lubumbashi, Democratic Republic of Congo. METHODS: A descriptive cross-sectional study was conducted in two hospitals in Lubumbashi in five inpatient units (Surgery, Gynecology and Obstetrics, Internal Medicine, Pediatrics and Recovery). The sample consisted of 171 hospitalized patients who were questioned using a standardized questionnaire. Patient's medical record allowed us to know the type of antibiotic administered to the patient 48 hours after admission. Our study was conducted in February 2010 as part of the first local prevalence survey on nosocomial infections. RESULTS: Our study collected data on 59 patients with nosocomial infection. The overall prevalence was 34.5% (17.0% with acquired nosocomial infection and 17.5% with imported infection). According to the World Health Organization, nosocomial infection is a hospital-acquired infection which was not present or incubating at the time of patient admission. The following risk factors have been associated with acquired nosocomial infections: duration of hospitalization (long stay hospital patients, hospital length of stay of more than seven days has a higher risk than shorter length of stay, hospital length of stay of less than or equal to seven days (prevalence ratio: RP =3.6 [IC A 95%.1.4-8.9])). Among nosocomial infections, surgical site infections were the most common (27.1%), followed by lung infections (22.0%) and urinary tract infections (17.0%). Microbiological examination highlighted five germs responsible for nosocomial infection in infected patients: Escherichia coli (11.9%), Staphylococcus aureus (6.8%), Pseudomonas aeruginosa (5.1%), Shigella spp (5.1%) and Salmonella typhimurium (1.7%). Microbiological examination was performed in 31.0% (n = 59). Cefotaxime, third-generation cephalosporin was the most prescribed antibiotic (37.9%), followed by amoxicillin (19.6%) and ampicillin (16.3%) for monotherapy. Dual and triple therapy was also prescribed. Parenteral route was the most used for anti-infective administration. There was a significant difference in the prevalence of nosocomial infections between the two university hospitals; the prevalence of acquired nosocomial infection was 22.2% in University Clinics of Lubumbashi and 13.1% in Sendwe hospital. CONCLUSION: In our study, the overall prevalence of nosocomial infections was 34.5%. Surgical site infections were the most common (27,1%). Escherichia coli was the most common germ (11.9%).

Monitoring of cellular responses after vaccination against tetanus toxoid: comparison of the measurement of IFN-gamma production by ELISA, ELISPOT, flow cytometry and real-time PCR.

One of the challenges for immunomonitoring in clinical trials is to detect an antigen specific T cell-mediated immune response. In an attempt to define the most suitable assay, tetanus toxoid was used to compare the capacity of 4 different methods to detect cytokine responses, before and after recall vaccination, in peripheral blood mononuclear cells (PBMC) of 14 healthy volunteers. ELISA, ELISPOT, intracytoplasmic detection and real-time RT-PCR were chosen to measure IFN-gamma production before and after vaccination. As far as the detection of memory T cell status (before vaccination) was concerned, we found that ELISPOT was the most sensitive method to discriminate TT-induced from spontaneous responses. On the other hand, intracytoplasmic cytokine detection was the most efficient method to detect the restimulating effect of TT vaccination.

Immune monitoring in whole blood using real-time PCR.

There is a need for simple and sensitive assays to assess innate and adaptive immune responses to microbial agents and vaccines. Herein, we describe a whole blood method allowing to measure the induction of cytokine synthesis at the mRNA level. The originality of this method consists in the combination of PAXgene tubes containing an mRNA stabilizer for blood collection, the MagNA Pure instrument as an automated system for mRNA extraction and RT-PCR reagent mix preparation, and the real-time PCR methodology on the Lightcycler for accurate and reproducible quantification of transcript levels. We first demonstrated that this method is adequate to measure the induction of interleukin (IL)-1beta and IL-1 receptor antagonist (IL-1 RA) mRNA upon the addition of bacterial lipopolysaccharide (LPS) to whole blood. We then showed that this approach is also suitable to detect the production of mRNA encoding T cell-derived cytokines in whole blood incubated with tetanus toxoid as a model of in vitro immune response to a recall antigen. Finally, we demonstrated that this methodology can be used successfully to assess inflammatory as well as T cell responses in vivo, as it allowed to detect the induction of IL-1beta and IL-1 RA after injection of LPS in healthy volunteers, and also the induction of IL-2 upon recall immunisation with tetanus vaccine.

Human herpesvirus-6 infection after lung and heart-lung transplantation: a prospective longitudinal study.

BACKGROUND: Although human herpesvirus (HHV)-6 is now recognized as a frequent pathogen after transplantation, the real impact of this infection in patients undergoing transplantation remains unclear. METHODS: During 27 months, 30 consecutive heart-lung- and lung-transplant recipients were included on the day of transplantation and prospectively followed during 100 days for HHV-6 infection. RESULTS: HHV-6 infection occurred in 20 (66%) patients after a median delay of 18 days after transplantation. The virus was detected by polymerase chain reaction or culture, or both, in 15.7 % of blood specimens, in 14.5% of bronchoalveolar lavage fluids, and in many organs at postmortem examination; it was found by culture in eight patients. No clinical manifestations could clearly be associated with HHV-6 alone. However, patients with HHV-6 infection had a higher mortality rate than patients without HHV-6 infection (7 of 20 vs. 0 of 10; P=0.04), and all the deceased patients died during periods of HHV-6 infection. We did not observe higher incidence of infectious or graft-rejection episodes in HHV-6-positive patients. However, eight of nine viral or fungal infections occurred during HHV-6 infection and three were directly responsible for death. CONCLUSION: Although frequently detected after transplantation, HHV-6 was not associated with any specific clinical manifestation. The higher mortality rate observed in patients with HHV-6 infection was not related to a higher incidence of bacterial infections or graft rejection but might be associated with more viral and fungal infections.

Infection control in the intensive care unit.

Nosocomial infections are common in many hospital departments, but particularly so on the intensive care unit, where they affect some 20 to 30% of patients. While early diagnosis and appropriate treatment are, of course, important, perhaps the greatest challenge is in the application of techniques to limit the development of such infections. This review will briefly discuss some of the background pathophysiology and epidemiology of nosocomial infection, and then focus on general and infection-specific preventative strategies individually and as part of broader infection-control programs with infection surveillance.

Impact of rapid molecular screening at hospital admission on nosocomial transmission of methicillin-resistant Staphylococcus aureus: cluster randomised trial.

DESIGN: Cluster randomised crossover trial with seven wards randomly allocated to intervention or control arm. SETTING: Medical and surgical wards of a university hospital with active MRSA control programme. PARTICIPANTS: All patients hospitalized >48 h in study wards and screened for MRSA on admission and discharge Intervention: Rapid PCR-based screening test for MRSA compared with control screening test by enrichment culture using chromogenic agar. OBJECTIVE: We determined the benefit of PCR-detection versus culture-based detection of MRSA colonisation upon patient admission on early implementation of isolation precautions and reduction of hospital transmission of MRSA. MAIN OUTCOME: Cumulative rate of MRSA hospital acquisition of in patients screened negative on admission. RANDOMIZATION: The sequential order of inclusion of study wards in each arm was randomised by assigning a number to each ward and using a computer generated list of random numbers. FINDINGS: Of 3704 eligible patients, 67.8% were evaluable for the study. Compared with culture, PCR-screening reduced the median test reporting time from admission from 88 to 11 hours (p<0.001) and the median time from admission to isolation from 96 to 25 hours (p<0.001). MRSA acquisition was detected in 36 patients (3.2%) in the control arm and 34 (3.2%) in the intervention arm. The incidence density rate of hospital acquired MRSA was 2.82 and 2.57/1,000 exposed patient-days in the control and intervention arm, respectively (risk ratio 0.91 (95% confidence interval, 0.60-1.39). Poisson regression model adjusted for colonisation pressure, compliance with hand hygiene and antibiotic use indicated a RR 0.99 (95% CI, 0.69 to 1.44). INTERPRETATION: Universal PCR screening for MRSA on admission to medical and surgical wards in an endemic setting shortened the time to implement isolation precautions but did not reduce nosocomial acquisition of MRSA. TRIAL REGISTRATION: clinicaltrials.gov NCT00846105.

A multicenter quasi-experimental study: impact of a central line infection control program using auditing and performance feedback in five Belgian intensive care units.

BACKGROUND: We analyzed the impact associated with an intervention based on process control and performance feedback to decrease central line-associated bloodstream infection (CLABSI) rates.This study was conducted from March 2011 to September 2012 in five adult intensive care units (ICU) located in two Belgian tertiary hospitals A and B, with a total of 53 beds. METHODS: This study was divided in three phases: P1 (baseline), P2 (intervention) and P3 (post intervention).During P2, external monitoring of five central venous catheters (CVC) care critical processes and monthly reporting (meetings and feedbacks reports posted) of performance indicators (CLABSI rate, CVC utilization ratio, compliance rate with each care process, and insertion site) to ICU workers were performed. The external monitoring of process measures was assessed by the same trained research nurse.A Poisson regression analysis was used to compare CLABSI incidence density rate per phase. Statistical significance was achieved with 2-sided p-value of <0.05. For the analysis, we separated the five ICU in hospital A and B when appropriate. RESULTS: Significantly improved total mean compliance was achieved for hand hygiene, CVC handling and CVC dressing. CLABSI rate declined from 4.00 (95% confidence interval (CI): 1.94-6.06) to 1.81 (0.46-3.17) per 1,000 CVC-days in P2 with an incidence rate ratio (IRR) of 0.49 (0.24-0.98, p = 0.043). A better response was observed in hospital A where the nurse participation at the monthly meeting was significantly higher than in hospital B (p < 0.001) as the percentage of feedbacks reports posted in ICU (p < 0.001). The decline in the CLABSI rate observed during P2 in comparison with P1 was independent of the insertion site (femoral or non-femoral; p = 0.054). The overall CLABSI rate increased to 2.73 (1.17-4.29) per 1,000 CVC-days with IRR of 0.67 (0.36-1.26, p = 0.212) in P3 compared to P1, but a high nursing turnover was observed in both hospitals. CONCLUSIONS: Our intervention focused on external auditing and performance feedback resulted in significant reduction in rates of CLABSI. Investigation continues regarding the most effective way to sustain CLABSI prevention practices and to improve the culture of safety in healthcare.

Variations in catheter-related bloodstream infections rates based on local practices.

BACKGROUND: Catheter-related bloodstream infection (CRBSI) surveillance serves as a quality improvement measure that is often used to assess performance. We reviewed the total number of microbiological samples collected in three Belgian intensive care units (ICU) in 2009-2010, and we described variations in CRBSI rates based on two factors: microbiological documentation rate and CRBSI definition which includes clinical criterion for coagulase-negative Staphylococcus (CNS) episode. FINDINGS: CRBSI rates were 2.95, 1.13 and 1.26 per 1,000 estimated catheter-days in ICUs A, B and C, respectively. ICU B cultured fewer microbiological samples and reported the lowest CRBSI rate. ICU C had the highest documentation rate but was assisted by support available from the laboratory for processing single CNS positive blood cultures. With the exclusion of clinical criterion, CRBSI rates would be reduced by 19%, 45% and 0% in ICUs A, B and C, respectively. CONCLUSION: CRBSI rates may be biased by differences of blood culture sampling and CRBSI definition. These observations suggest that comparisons of CRBSI rates in different ICUs remain difficult to interpret without knowledge of local practices.

Antibiotic policy: a tool for controlling resistance of hospital pathogens.

Multiresistant Gram-negative bacilli, including strains of Klebsiella pneumoniae, Enterobacter spp, Acinetobacter baumannii and Pseudomonas aeruginosa, resistant to broad spectrum beta-lactams, aminoglycosides and fluoroquinolones, are recovered at increasing frequency from patients suffering from nosocomial infections, particularly from those receiving intensive care. The emergence and spread of resistant pathogens to endemic and epidemic levels has frequently been related in time and place to the intensive use of antibiotics to which these microorganisms have developed resistance, notably third generation cephalosporins and fluoroquinolones. Recent investigations have indicated that the prevalence of resistance can be reduced by scheduled changes of empiric treatment regimens, involving discontinuation of intensively prescribed drugs and substitution with newly introduced antibiotics of another class to which the prevalent resistant strains remain susceptible. Among these drugs, penicillins---beta-lactamase inhibitor combinations, 'fourth generation' cephalosporins and, where little used previously, fluoroquinolones, have been introduced successfully in high risk units where ceftazidime-resistant strains of K.pneumoniae, Enterobacter and Citrobacter spp or glycopeptide-resistant enterococci had become highly prevalent. However, these studies do not demonstrate a direct causal relationship between changes in prescribing practices and ecological improvements, because their observational design cannot be controlled. In most studies, several important factors influencing the dynamics of resistance were not monitored and the relative contribution of decreased emergence versus control of cross-transmission to the improved susceptibility rates is not clear. We propose that additional long-term studies are required to better track the ecological impact and to determine the optimal modalities of programmed changes of antibiotic prescribing as an antibiotic resistance prevention or control strategy.

Evaluation of tumor necrosis factor-alpha, interleukin-6 and C-reactive protein plasma levels as predictors of bacteremia in patients presenting signs of sepsis without shock.

OBJECTIVE: To evaluate the sensitivity of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) plasma measurement to detect bacteremia in patients presenting sepsis signs, and to evaluate the potential benefit of such measurement in terms of early antimicrobial therapy initiation. METHODS: Plasma was obtained from 166 hospitalized patients for whom blood cultures were drawn for sepsis. Clinical data and antimicrobial therapies were noted. IL-6, TNF and C-reactive protein (CRP) were measured. The sensitivities of these markers were retrospectively compared with the accuracy of the attending physician in initiating empirical antimicrobial therapy. The setting was an 850-bed university hospital. RESULTS: Thirty-four bacteremias and 69 non-bacteremic infections were noted. In 63 others, no infection was documented. Median (range) IL-6 plasma levels in the three groups of patients were 462 (15--50 850), 189 (<15--38 300) and 91 (<10--13 750) pg/mL, respectively (p<0.01). The corresponding TNF-alpha plasma levels were 37.5 (<15--2400), 15 (<15--240) and 15 (<15--200) pg/mL, respectively (p<0.01). CRP plasma levels were 10.7 (<0.6--30.2), 10.3 (<0.6--34.4) and 7.3 (<0.6--20.9) mg/dL, respectively (p=0.12). With respect to these three parameters, IL-6 and TNF-alpha appear better than CRP for predicting bacteremia. Clinical features resulted in starting empirical antimicrobial therapy in only 62% of the bacteremic patients. On the other hand, 68% of these bacteremic patients had high IL-6 plasma levels (>200 pg/mL). A combination of clinical features and high IL-6 levels would have permitted early treatment for 82% of the bacteremic patients. CONCLUSIONS: IL-6 and TNF-alpha thus appear to be useful and earlier markers of bacteremia in septic patients. By contrast, CRP is neither sensitive nor specific in this setting.

Emergence of vancomycin-intermediate Staphylococcus aureus in a Belgian hospital: microbiological and clinical features.

In 1999, all clinical Staphylococcus aureus isolates from patients admitted to a Belgian University hospital were tested for decreased vancomycin susceptibility. Three vancomycin-intermediate Staphylococcus aureus (VISA) and four hetero-VISA strains were detected among 2145 isolates tested. They emerged from strains that belonged to locally endemic methicillin-resistant S. aureus (MRSA) genotypes in three patients who had received repeated courses of vancomycin therapy. A cystic fibrosis patient with MRSA/VISA-associated broncho-pulmonary exacerbation was successfully treated by continuous vancomycin infusion plus fusidic acid followed by oral minocycline-fusidic acid. Two other patients had VISA recovered from specimens of undetermined clinical significance. Emergence of VISA variants of endemic MRSA strains in Belgium warrants active microbiological surveillance and careful monitoring of vancomycin therapy. Therapy with high-dose vancomycin administered by continuous infusion in combination with other antimicrobials may be a therapeutic option worth investigating for VISA infection.

Vancomycin penetration of uninfected pleural fluid exudate after continuous or intermittent infusion.

Blood and pleural exudate samples were obtained from 16 patients receiving intermittent or continuous infusions of vancomycin after lung surgery. The areas under the concentration-time curves for blood and pleural exudates were identical for both administration schedules, while continuous infusion allowed the concentrations in pleural exudates to be more sustained (mean concentration, 12 mg/liter).