Development and validation of risk prediction model for bacterial infections in acute liver failure patients.

Infections significantly increase mortality in acute liver failure (ALF) patients, and there are no risk prediction models for early diagnosis and treatment of infections in ALF patients. This study aims to develop a risk prediction model for bacterial infections in ALF patients to guide rational antibiotic therapy. The data of ALF patients admitted to the Second Hospital of Hebei Medical University in China from January 2017 to January 2022 were retrospectively analyzed for training and internal validation. Patients were selected according to the updated 2011 American Association for the Study of Liver Diseases position paper on ALF. Serological indicators and model scores were collected within 24 h of admission. New models were developed using the multivariate logistic regression analysis. An optimal model was selected by receiver operating characteristic (ROC) analysis, Hosmer-Lemeshow test, the calibration curve, the Brier score, the bootstrap resampling, and the decision curve analysis. A nomogram was plotted to visualize the results. A total of 125 ALF patients were evaluated and 79 were included in the training set. The neutrophil-to-lymphocyte ratio and sequential organ failure assessment (SOFA) were integrated into the new model as independent predictive factors. The new SOFA-based model outperformed other models with an area under the ROC curve of 0.799 [95% confidence interval (CI): 0.652-0.926], the superior calibration and predictive performance in internal validation. High-risk individuals with a nomogram score ≥26 are recommended for antibiotic therapy. The new SOFA-based model demonstrates high accuracy and clinical utility in guiding antibiotic therapy in ALF patients.

[Optimization of the puncture treatment method for acute bacterial maxillary sinusitis]. / Optimizatsiya metoda punktsionnogo lecheniya ostrogo bakterial'nogo verkhnechelyustnogo sinusita.

OBJECTIVE: Optimization of the method of puncture treatment of acute bacterial maxillary sinusitis (ABMS) through the development of original devices for drainage of the maxillary sinus (MS). MATERIAL AND METHODS: Registration and comparative analysis of the results of puncture methods of treatment of 120 patients with ABMS using developed new original devices for drainage of MS with one channels and with two channels in comparison with the Kulikovsky's needle (KN) was carried out. Based on the results of the analysis, the effectiveness of the original devices was assessed. During the clinical study, patients were divided into two groups: in group I, patients underwent of the MS puncture using KN, in group II, using original devices. Groups I and II, depending on the absence or presence of a block of the natural anastomosis MS, was divided into subgroups A and B, respectively. After puncture of the MS, the pain syndrome was assessed by patients using Visual Analogue Scale (VAS) and by doctors - using Touch Visual Pain (TVP) scale. RESULTS: Our study showed that when puncturing the upper jaw with an original needle with one channels and with two channels, compared with the use of KN, there is a decrease in pain (the average VAS score was 1.5±0.3 and 1.7±0.3 points, respectively; the average TVP scale score was 0.9±0.2 and 1.8±0.3 points, respectively, the difference is significant, p≤0.05). Patients of subgroup IB were manipulated with two KN, patients of subgroup IIB manipulated using the original device with two channels without an additional needle (the average VAS score was 3.0±0.4 and 1.3±0.3 points, respectively; the average TVP scale score was 2.7±0.4 and 1.0±0.2 points, respectively, the difference is significant, p≤0.05). The doctors also assessed the devices used for puncture of the upper jaw. As a result of the study, the high efficiency and safety of using new original devices was established.

Blood calprotectin as a biomarker for infection and sepsis - the prospective CASCADE trial.

BACKGROUND: Early in the host-response to infection, neutrophils release calprotectin, triggering several immune signalling cascades. In acute infection management, identifying infected patients and stratifying these by risk of deterioration into sepsis, are crucial tasks. Recruiting a heterogenous population of patients with suspected infections from the emergency department, early in the care-path, the CASCADE trial aimed to evaluate the accuracy of blood calprotectin for detecting bacterial infections, estimating disease severity, and predicting clinical deterioration. METHODS: In a prospective, observational trial from February 2021 to August 2022, 395 patients (n = 194 clinically suspected infection; n = 201 controls) were enrolled. Blood samples were collected at enrolment. The accuracy of calprotectin to identify bacterial infections, and to predict and identify sepsis and mortality was analysed. These endpoints were determined by a panel of experts. RESULTS: The Area Under the Receiver Operating Characteristic (AUROC) of calprotectin for detecting bacterial infections was 0.90. For sepsis within 72 h, calprotectin's AUROC was 0.83. For 30-day mortality it was 0.78. In patients with diabetes, calprotectin had an AUROC of 0.94 for identifying bacterial infection. CONCLUSIONS: Calprotectin showed notable accuracy for all endpoints. Using calprotectin in the emergency department could improve diagnosis and management of severe infections, in combination with current biomarkers. CLINICAL TRIAL REGISTRATION NUMBER: DRKS00020521.

Development of a multiplex Loop-Mediated Isothermal Amplification (LAMP) for the diagnosis of bacterial periprosthetic joint infection.

BACKGROUND: Periprosthetic joint infection (PJI) is one of the most serious and debilitating complications that can occur after total joint arthroplasty. Therefore, early diagnosis and appropriate treatment are important for a good prognosis. Recently, molecular diagnostic methods have been widely used to detect the causative microorganisms of PJI sensitively and rapidly. The Multiplex Loop-Mediated Isothermal Amplification (LAMP) method eliminates the complex temperature cycling and delays caused by temperature transitions seen in polymerase chain reaction (PCR) methods, making it faster and easier to perform compared to PCR-based assays. Therefore, this study developed a multiplex LAMP assay for diagnosing bacterial PJI using LAMP technology and evaluated its analytical and clinical performance. METHODS: We developed a multiplex LAMP assay for the detection of five bacteria: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Pseudomonas aeruginosa, and Escherichia coli, frequently observed to be the causative agents of PJI. The method of analytical sensitivity and cross-reactivity were determined by spiking standard strains into the joint synovial fluid. The analytical sensitivity of the multiplex LAMP assay was compared with that of a quantitative real-time PCR (qPCR) assay. Clinical performance was evaluated using 20 joint synovial fluid samples collected from patients suspected of having bacterial PJI. RESULTS: The analytical sensitivity of the gram-positive bacterial multiplex LAMP assay and qPCR were 105/104 CFU/mL, 103/103 CFU/mL, and 105/104 CFU/mL against S. agalactiae, S. epidermidis, and S. aureus, respectively. For P. aeruginosa and E. coli, the analytical sensitivity of the multiplex LAMP and qPCR assays were 105/104 and 106/104 CFU/mL, respectively. The multiplex LAMP assay detects target bacteria without cross-reacting with other bacteria, and exhibited 100% sensitivity and specificity in clinical performance evaluation. CONCLUSIONS: This multiplex LAMP assay can rapidly detect five high-prevalence bacterial species causing bacterial PJI, with excellent sensitivity and specificity, in less than 1 h, and it may be useful for the early diagnosis of PJI.

Role of biomarkers in antimicrobial stewardship: physicians' perspectives.

Biomarkers are playing an increasingly important role in antimicrobial stewardship. Their applications have included use in algorithms that evaluate suspected bacterial infections or provide guidance on when to start or stop antibiotic therapy, or when therapy should be repeated over a short period (6-12 h). Diseases in which biomarkers are used as complementary tools to determine the initiation of antibiotics include sepsis, lower respiratory tract infection (LRTI), COVID-19, acute heart failure, infectious endocarditis, acute coronary syndrome, and acute pancreatitis. In addition, cut-off values of biomarkers have been used to inform the decision to discontinue antibiotics for diseases such as sepsis, LRTI, and febrile neutropenia. The biomarkers used in antimicrobial stewardship include procalcitonin (PCT), C-reactive protein (CRP), presepsin, and interleukin (IL)-1ß/IL-8. The cut-off values vary depending on the disease and study, with a range of 0.25-1.0 ng/mL for PCT and 8-50 mg/L for CRP. Biomarkers can complement clinical diagnosis, but further studies of microbiological biomarkers are needed to ensure appropriate antibiotic selection.

Application value of metagenomic next-generation sequencing in hematological patients with high-risk febrile neutropenia.

Background: Metagenomic next-generation sequencing (mNGS) is a novel non-invasive and comprehensive technique for etiological diagnosis of infectious diseases. However, its practical significance has been seldom reported in the context of hematological patients with high-risk febrile neutropenia, a unique patient group characterized by neutropenia and compromised immune responses. Methods: This retrospective study evaluated the results of plasma cfDNA sequencing in 164 hematological patients with high-risk febrile neutropenia. We assessed the diagnostic efficacy and clinical impact of mNGS, comparing it with conventional microbiological tests. Results: mNGS identified 68 different pathogens in 111 patients, whereas conventional methods detected only 17 pathogen types in 36 patients. mNGS exhibited a significantly higher positive detection rate than conventional methods (67.7% vs. 22.0%, P < 0.001). This improvement was consistent across bacterial (30.5% vs. 9.1%), fungal (19.5% vs. 4.3%), and viral (37.2% vs. 9.1%) infections (P < 0.001 for all comparisons). The anti-infective treatment strategies were adjusted for 51.2% (84/164) of the patients based on the mNGS results. Conclusions: mNGS of plasma cfDNA offers substantial promise for the early detection of pathogens and the timely optimization of anti-infective therapies in hematological patients with high-risk febrile neutropenia.

Application of metagenomic next-generation sequencing in optimizing the diagnosis of ascitic infection in patients with liver cirrhosis.

BACKGROUND: Metagenomic next-generation sequencing (mNGS) is an emerging technique for the clinical diagnosis of infectious disease that has rarely been used for the diagnosis of ascites infection in patients with cirrhosis. This study compared mNGS detection with conventional culture methods for the on etiological diagnosis of cirrhotic ascites and evaluated the clinical effect of mNGS. METHODS: A total of 109 patients with ascites due to cirrhosis were included in the study. We compared mNGS with conventional culture detection by analyzing the diagnostic results, pathogen species and clinical effects. The influence of mNGS on the diagnosis and management of ascites infection in patients with cirrhosis was also evaluated. RESULTS: Ascites cases were classified into three types: spontaneous bacterial peritonitis (SBP) (16/109, 14.7%), bacterascites (21/109, 19.3%) and sterile ascites (72/109, 66.1%). In addition, 109 patients were assigned to the ascites mNGS-positive group (80/109, 73.4%) or ascites mNGS-negative group (29/109, 26.6%). The percentage of positive mNGS results was significantly greater than that of traditional methods (73.4% vs. 28.4%, P < 0.001). mNGS detected 43 strains of bacteria, 9 strains of fungi and 8 strains of viruses. Fourteen bacterial strains and 3 fungal strains were detected via culture methods. Mycobacteria, viruses, and pneumocystis were detected only by the mNGS method. The mNGS assay produced a greater polymicrobial infection rate than the culture method (55% vs. 16%). Considering the polymorphonuclear neutrophil (PMN) counts, the overall percentage of pathogens detected by the two methods was comparable, with 87.5% (14/16) in the PMN ≥ 250/mm3 group and 72.0% (67/93) in the PMN < 250/mm3 group (P > 0.05). Based on the ascites PMN counts combined with the mNGS assay, 72 patients (66.1%) were diagnosed with ascitic fluid infection (AFI) (including SBP and bacterascites), whereas based on the ascites PMN counts combined with the culture assay, 37 patients (33.9%) were diagnosed with AFI (P < 0.05). In 60 (55.0%) patients, the mNGS assay produced positive clinical effects; 40 (85.7%) patients had their treatment regimen adjusted, and 48 patients were improved. The coincidence rate of the mNGS results and clinical findings was 75.0% (60/80). CONCLUSIONS: Compared with conventional culture methods, mNGS can improve the detection rate of ascites pathogens, including bacteria, viruses, and fungi, and has significant advantages in the diagnosis of rare pathogens and pathogens that are difficult to culture; moreover, mNGS may be an effective method for improving the diagnosis of ascites infection in patients with cirrhosis, guiding early antibiotic therapy, and for reducing complications related to abdominal infection. In addition, explaining mNGS results will be challenging, especially for guiding the treatment of infectious diseases.

Development and evaluation of an artificial intelligence for bacterial growth monitoring in clinical bacteriology.

In clinical bacteriology laboratories, reading and processing of sterile plates remain a significant part of the routine workload (30%-40% of the plates). Here, an algorithm was developed for bacterial growth detection starting with any type of specimens and using the most common media in bacteriology. The growth prediction performance of the algorithm for automatic processing of sterile plates was evaluated not only at 18-24 h and 48 h but also at earlier timepoints toward the development of an early growth monitoring system. A total of 3,844 plates inoculated with representative clinical specimens were used. The plates were imaged 15 times, and two different microbiologists read the images randomly and independently, creating 99,944 human ground truths. The algorithm was able, at 48 h, to discriminate growth from no growth with a sensitivity of 99.80% (five false-negative [FN] plates out of 3,844) and a specificity of 91.97%. At 24 h, sensitivity and specificity reached 99.08% and 93.37%, respectively. Interestingly, during human truth reading, growth was reported as early as 4 h, while at 6 h, half of the positive plates were already showing some growth. In this context, automated early growth monitoring in case of normally sterile samples is envisioned to provide added value to the microbiologists, enabling them to prioritize reading and to communicate early detection of bacterial growth to the clinicians.

Automatic Microfluidic Harmonized RAA-CRISPR Diagnostic System for Rapid and Accurate Identification of Bacterial Respiratory Tract Infections.

Respiratory tract infections (RTIs) pose a grave threat to human health, with bacterial pathogens being the primary culprits behind severe illness and mortality. In response to the pressing issue, we developed a centrifugal microfluidic chip integrated with a recombinase-aided amplification (RAA)-clustered regularly interspaced short palindromic repeats (CRISPR) system to achieve rapid detection of respiratory pathogens. The limitations of conventional two-step CRISPR-mediated systems were effectively addressed by employing the all-in-one RAA-CRISPR detection method, thereby enhancing the accuracy and sensitivity of bacterial detection. Moreover, the integration of a centrifugal microfluidic chip led to reduced sample consumption and significantly improved the detection throughput, enabling the simultaneous detection of multiple respiratory pathogens. Furthermore, the incorporation of Chelex-100 in the sample pretreatment enabled a sample-to-answer capability. This pivotal addition facilitated the deployment of the system in real clinical sample testing, enabling the accurate detection of 12 common respiratory bacteria within a set of 60 clinical samples. The system offers rapid and reliable results that are crucial for clinical diagnosis, enabling healthcare professionals to administer timely and accurate treatment interventions to patients.

Performance of Febrile Infant Algorithms by Duration of Fever.

OBJECTIVES: To analyze the performance of commonly used blood tests in febrile infants ≤90 days of age to identify patients at low risk for invasive bacterial infection (bacterial pathogen in blood or cerebrospinal fluid) by duration of fever. METHODS: We conducted a secondary analysis of a prospective single-center registry that includes all consecutive infants ≤90 days of age with fever without a source evaluated at 1 pediatric emergency department between 2008 and 2021. We defined 3 groups based on caregiver-reported hours of fever (<2, 2-12, and ≥12) and analyzed the performance of the biomarkers and Pediatric Emergency Care Applied Research Network, American Academy of Pediatrics, and Step-by-Step clinical decision rules. RESULTS: We included 2411 infants; 76 (3.0%) were diagnosed with an invasive bacterial infection. The median duration of fever was 4 (interquartile range, 2-12) hours, with 633 (26.3%) patients with fever of <2 hours. The area under the curve was significantly lower in patients with <2 hours for absolute neutrophil count (0.562 vs 0.609 and 0.728) and C-reactive protein (0.568 vs 0.760 and 0.812), but not for procalcitonin (0.749 vs 0.780 and 0.773). Among well-appearing infants older than 21 days and negative urine dipstick with <2 hours of fever, procalcitonin ≥0.14 ng/mL showed a better sensitivity (100% with specificity 53.8%) than that of the combination of biomarkers of Step-by-Step (50.0% and 82.2%), and of the American Academy of Pediatrics and Pediatric Emergency Care Applied Research Network rules (83.3% and 58.3%), respectively. CONCLUSIONS: The performance of blood biomarkers, except for procalcitonin, in febrile young infants is lower in fever of very short duration, decreasing the accuracy of the clinical decision rules.

Syndromic testing for respiratory pathogens but not National Early Warning Score can be used to identify viral cause in hospitalised adults with lower respiratory tract infections.

BACKGROUND: Community-acquired lower respiratory tract infection (LRTI) is a common reason for hospitalisation. Antibiotics are frequently used while diagnostic microbiological methods are underutilised in the acute setting. OBJECTIVES: We aimed to investigate the relative proportion of viral and bacterial infections in this patient group and explore methods for proper targeting of antimicrobial therapy. METHODS: We collected nasopharyngeal samples prospectively from adults hospitalised with LRTIs during three consecutive winter seasons (2016-2019). Syndromic nasopharyngeal testing was performed using a multiplex PCR panel including 16 viruses and four bacteria. Medical records were reviewed for clinical data. RESULTS: Out of 220 included patients, a viral pathogen was detected in 74 (34%), a bacterial pathogen in 63 (39%), both viral and bacterial pathogens in 49 (22%), while the aetiology remained unknown in 34 (15%) cases. The proportion of infections with an identified pathogen increased from 38% to 85% when syndromic testing was added to standard-of-care testing. Viral infections were associated with a low CRP level and absence of pulmonary infiltrates. A high National Early Warning Score did not predict bacterial infections. CONCLUSIONS: Syndromic testing by a multiplex PCR panel identified a viral infection or viral/bacterial coinfection in a majority of hospitalised adult patients with community-acquired LRTIs.

Serious bacterial infection risk in recently immunized febrile infants in the emergency department.

STUDY OBJECTIVES: Fever following immunizations is a common presenting chiefcomplaint among infants. The 2021 American Academy of Pediatrics (AAP) febrile infant clinical practice guidelines exclude recently immunized (RI) infants. This is a challenge for clinicians in the management of the febrile RI young infant. The objective of this study was to assess the prevalence of SBI in RI febrile young infants between 6 and 12 weeks of age. METHODS: This was a retrospective chart review of infants 6-12 weeks who presented with a fever ≥38 °C to two U.S. military academic Emergency Departments over a four-year period. Infants were considered recently immunized (RI) if they had received immunizations in the preceding 72 h prior to evaluation and not recently immunized (NRI) if they had not received immunizations during this time period. The primary outcome was prevalence of serious bacterial infection (SBI) further delineated into invasive-bacterial infection (IBI) and non-invasive bacterial infection (non-IBI) based on culture and/or radiograph reports. RESULTS: Of the 508 febrile infants identified, 114 had received recent immunizations in the preceding 72 h. The overall prevalence of SBI was 11.4% (95% CI = 8.9-14.6) in our study population. The prevalence of SBI in NRI infants was 13.7% (95% CI = 10.6-17.6) compared to 3.5% (95% CI = 1.1-9.3) in RI infants. The relative risk of SBI in the setting of recent immunizations was 0.3 (95% CI = 0.1-0.7). There were no cases of invasive-bacterial infections (IBI) in the RI group with all but one of the SBI being urinary tract infections (UTI). The single non-UTI was a case of pneumonia in an infant who presented with respiratory symptoms within 24 h of immunizations. CONCLUSION: The risk of IBI (meningitis or bacteremia) in RI infants aged 6 to 12 weeks is low. Non-IBI within the first 24 h following immunization was significantly lower than in febrile NRI infants. UTIs remain a risk in the RI population and investigation with urinalysis and urine culture should be encouraged. Shared decision making with families guide a less invasive approach to the care of these children. Future research utilizing a large prospective multi-center data registry would aid in further defining the risk of both IBI and non-IBI among RI infants.

An evolution of Nanopore next-generation sequencing technology: implications for medical microbiology and public health.

Next-generation sequencing has evolved as a powerful tool, with applications that extend from diagnosis to public health surveillance and outbreak investigations. Short-read sequencing, using primarily Illumina chemistry, has been the prevailing approach. Single-molecule sensing and long-read sequencing using Oxford Nanopore Technologies (ONT) has witnessed a breakthrough in the evolution of the technology, performance, and applications in the past few years. In this issue of the Journal of Clinical Microbiology, Bogaerts et al. (https://doi.org/10.1128/jcm.01576-23) describe the utility of the latest ONT sequencing technology, the R10.4.1, in bacterial outbreak investigations. The authors demonstrate that ONT R10.4.1 technology can be comparable to Illumina sequencing for single-nucleotide polymorphism-based phylogeny. The authors emphasize that the reproducibility between ONT and Illumina technologies could facilitate collaborations among laboratories utilizing different sequencing platforms for outbreak investigations.

Development of an automated amplicon-based next-generation sequencing pipeline for rapid detection of bacteria and fungi directly from clinical specimens.

The timely identification of microbial pathogens is essential to guide targeted antimicrobial therapy and ultimately, successful treatment of an infection. However, the yield of standard microbiology testing (SMT) is directly related to the duration of antecedent antimicrobial therapy as SMT culture methods are dependent on the recovery of viable organisms, the fastidious nature of certain pathogens, and other pre-analytic factors. In the last decade, metagenomic next-generation sequencing (mNGS) has been successfully utilized as a diagnostic tool for various applications within the clinical laboratory. However, mNGS is resource, time, and labor-intensive-requiring extensive laborious preliminary benchwork, followed by complex bioinformatic analysis. We aimed to address these shortcomings by developing a largely Automated targeted Metagenomic next-generation sequencing (tmNGS) PipeLine for rapId inFectIous disEase Diagnosis (AMPLIFIED) to detect bacteria and fungi directly from clinical specimens. Therefore, AMPLIFIED may serve as an adjunctive approach to complement SMT. This tmNGS pipeline requires less than 1 hour of hands-on time before sequencing and less than 2 hours of total processing time, including bioinformatic analysis. We performed tmNGS on 50 clinical specimens with concomitant cultures to assess feasibility and performance in the hospital laboratory. Of the 50 specimens, 34 (68%) were from true clinical infections. Specimens from cases of true infection were more often tmNGS positive compared to those from the non-infected group (82.4% vs 43.8%, respectively, P = 0.0087). Overall, the clinical sensitivity of AMPLIFIED was 54.6% with 85.7% specificity, equating to 70.6% and 75% negative and positive predictive values, respectively. AMPLIFIED represents a rapid supplementary approach to SMT; the typical time from specimen receipt to identification of potential pathogens by AMPLIFIED is roughly 24 hours which is markedly faster than the days, weeks, and months required to recover bacterial, fungal, and mycobacterial pathogens by culture, respectively. IMPORTANCE: To our knowledge, this represents the first application of an automated sequencing and bioinformatics pipeline in an exclusively pediatric population. Next-generation sequencing is time-consuming, labor-intensive, and requires experienced personnel; perhaps contributing to hesitancy among clinical laboratories to adopt such a test. Here, we report a strong case for use by removing these barriers through near-total automation of our sequencing pipeline.

Simple, sensitive, and visual detection of 12 respiratory pathogens with one-pot-RPA-CRISPR/Cas12a assay.

Respiratory infections pose a serious threat to global public health, underscoring the urgent need for rapid, accurate, and large-scale diagnostic tools. In recent years, the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system, combined with isothermal amplification methods, has seen widespread application in nucleic acid testing (NAT). However, achieving a single-tube reaction system containing all necessary components is challenging due to the competitive effects between recombinase polymerase amplification (RPA) and CRISPR/Cas reagents. Furthermore, to enable precision medicine, distinguishing between bacterial and viral infections is essential. Here, we have developed a novel NAT method, termed one-pot-RPA-CRISPR/Cas12a, which combines RPA with CRISPR molecular diagnostic technology, enabling simultaneous detection of 12 common respiratory pathogens, including six bacteria and six viruses. RPA and CRISPR/Cas12a reactions are separated by paraffin, providing an independent platform for RPA reactions to generate sufficient target products before being mixed with the CRISPR/Cas12a system. Results can be visually observed under LED blue light. The sensitivity of the one-pot-RPA-CRISPR/Cas12a method is 2.5 × 100 copies/µL plasmids, with no cross-reaction with other bacteria or viruses. Additionally, the clinical utility was evaluated by testing clinical isolates of bacteria and virus throat swab samples, demonstrating favorable performance. Thus, our one-pot-RPA-CRISPR/Cas12a method shows immense potential for accurate and large-scale detection of 12 common respiratory pathogens in point-of-care testing.

Microbiological diagnosis of pleural infections: a comparative evaluation of a novel syndromic real-time PCR panel.

Current microbial diagnostics for pleural infections are insufficient. Studies using 16S targeted next-generation sequencing report that only 10%-16% of bacteria present are cultured and that 50%-78% of pleural fluids containing relevant microbial DNA remain culture negative. As a rapid diagnostic alternative suitable for clinical laboratories, we wanted to explore a PCR-based approach. Based on the identification of key pathogens, we developed a syndromic PCR panel for community-acquired pleural infections (CAPIs). This was a pragmatic PCR panel, meaning that it was not designed for detecting all possibly involved bacterial species but for confirming the diagnosis of CAPI, and for detecting bacteria that might influence choice of antimicrobial treatment. We evaluated the PCR panel on 109 confirmed CAPIs previously characterized using culture and 16S targeted next-generation sequencing. The PCR secured the diagnosis of CAPI in 107/109 (98.2%) and detected all present pathogens in 69/109 (63.3%). Culture secured the diagnosis in 54/109 (49.5%) and detected all pathogens in 31/109 (28.4%). Corresponding results for 16S targeted next-generation sequencing were 109/109 (100%) and 98/109 (89.9%). For bacterial species included in the PCR panel, PCR had a sensitivity of 99.5% (184/185), culture of 21.6% (40/185), and 16S targeted next-generation sequencing of 92.4% (171/185). None of the bacterial species present not covered by the PCR panel were judged to impact antimicrobial therapy. A syndromic PCR panel represents a rapid and sensitive alternative to current diagnostic approaches for the microbiological diagnosis of CAPI.IMPORTANCEPleural empyema is a severe infection with high mortality and increasing incidence. Long hospital admissions and long courses of antimicrobial treatment drive healthcare and ecological costs. Current methods for microbiological diagnostics of pleural infections are inadequate. Recent studies using 16S targeted next-generation sequencing as a reference standard find culture to recover only 10%-16% of bacteria present and that 50%-78% of samples containing relevant bacterial DNA remain culture negative. To confirm the diagnosis of pleural infection and define optimal antimicrobial therapy while limiting unnecessary use of broad-spectrum antibiotics, there is a need for rapid and sensitive diagnostic approaches. PCR is a rapid method well suited for clinical laboratories. In this paper we show that a novel syndromic PCR panel can secure the diagnosis of pleural infection and detect all bacteria relevant for choice of antimicrobial treatment with a high sensitivity.

Diagnostic test accuracy of procalcitonin and C-reactive protein for predicting invasive and serious bacterial infections in young febrile infants: a systematic review and meta-analysis.

BACKGROUND: Febrile infants presenting in the first 90 days of life are at higher risk of invasive and serious bacterial infections than older children. Modern clinical practice guidelines, mostly using procalcitonin as a diagnostic biomarker, can identify infants who are at low risk and therefore suitable for tailored management. C-reactive protein, by comparison, is widely available, but whether C-reactive protein and procalcitonin have similar diagnostic accuracy is unclear. We aimed to compare the test accuracy of procalcitonin and C-reactive protein in the prediction of invasive or serious bacterial infections in febrile infants. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, EMBASE, Web of Science, and The Cochrane Library for diagnostic test accuracy studies up to June 19, 2023, using MeSH terms "procalcitonin", and "bacterial infection" or "fever" and keywords "invasive bacterial infection*" and "serious bacterial infection*", without language or date restrictions. Studies were selected by independent authors against eligibility criteria. Eligible studies included participants aged 90 days or younger presenting to hospital with a fever (≥38°C) or history of fever within the preceding 48 h. The primary index test was procalcitonin, and the secondary index test was C-reactive protein. Test kits had to be commercially available, and test samples had to be collected upon presentation to hospital. Invasive bacterial infection was defined as the presence of a bacterial pathogen in blood or cerebrospinal fluid, as detected by culture or quantitative PCR; authors' definitions of serious bacterial infection were used. Data were extracted from selected studies, and the detection of invasive or serious bacterial infections was analysed with two models for each biomarker. Diagnostic accuracy was determined against internationally recognised cutoff values (0·5 ng/mL for procalcitonin, 20 mg/L for C-reactive protein) and pooled to calculate partial area under the curve (pAUC) values for each biomarker. Optimum cutoff values were identified for each biomarker. This study is registered with PROSPERO, CRD42022293284. FINDINGS: Of 734 studies derived from the literature search, 14 studies (n=7755) were included in the meta-analysis. For the detection of invasive bacterial infections, pAUC values were greater for procalcitonin (0·72, 95% CI 0·56-0·79) than C-reactive protein (0·28, 0·17-0·61; p=0·016). Optimal cutoffs for detecting invasive bacterial infections were 0·49 ng/mL for procalcitonin and 13·12 mg/L for C-reactive protein. For the detection of serious bacterial infections, procalcitonin and C-reactive protein had similar pAUC values (0·55, 0·44-0·69 vs 0·54, 0·40-0·61; p=0·92). For serious bacterial infections, the optimal cutoffs for procalcitonin and C-reactive protein were 0·17 ng/mL and 16·18 mg/L, respectively. Heterogeneity was low for studies investigating the test accuracy of procalcitonin in detecting invasive bacterial infection (I2=23·5%), high for studies investigating procalcitonin for serious bacterial infection (I2=75·5%), and moderate for studies investigating C-reactive protein for invasive bacterial infection (I2=49·5%) and serious bacterial infection (I2=28·3%). The absence of a single definition of serious bacterial infection across studies was the greatest source of interstudy variability and potential bias. INTERPRETATION: Within a large cohort of febrile infants, a procalcitonin cutoff of 0·5 ng/mL had a superior pAUC value to a C-reactive protein cutoff of 20 mg/L for identifying invasive bacterial infections. In settings without access to procalcitonin, C-reactive protein should therefore be used cautiously for the identification of invasive bacterial infections, and a cutoff value below 20 mg/L should be considered. C-reactive protein and procalcitonin showed similar test accuracy for the identification of serious bacterial infection with internationally recognised cutoff values. This might reflect the challenges involved in confirming serious bacterial infection and the absence of a universally accepted definition of serious bacterial infection. FUNDING: None.

Protocol for the diagnostic performance of C reactive protein, procalcitonin and interleukin-6 for serious bacterial infections among children ≤36 months old presenting with fever without source: a systematic review and meta-analysis.

INTRODUCTION: The management of fever without source in children ≤36 months old remains a diagnostic challenge as the underlying aetiologies can vary from self-limiting viral infections to serious bacterial infections (SBIs). Biomarkers such as C reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6) have varying thresholds in the prediction of SBIs due to differences in SBI definitions, SBI prevalence, patient characteristics and timing of presentation. This protocol describes a systematic review and meta-analysis that aims to determine the thresholds at which CRP, PCT and IL-6 can perform optimally in distinguishing the presence of SBIs in children ≤36 months old, as well as to determine their performances in early detection of bacterial infections within 48 hours of fever onset. METHODS AND ANALYSIS: We will systematically search electronic databases including MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane CENTRAL, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and Science Citation Index from 1 July 2023 to 31 July 2023. We will include studies that report the diagnostic accuracy of CRP, PCT and IL-6 in detecting SBIs in children aged ≤36 months presenting with fever without apparent source. Randomised controlled trials (RCTs) and non-randomised studies including non-RCTs and controlled before-and-after studies will be included. A meta-analysis will be performed and diagnostic performances of these biomarkers will be reported. ETHICS AND DISSEMINATION: The results of this study will provide guidance on clinical decision-making in young children presenting with fever without source. Ethics approval will not be required for this study. The authors aim to publish the findings in a peer-reviewed journal as well as present at international conferences. PROSPERO REGISTRATION NUMBER: CRD42023439093.

Expert consensus on the diagnosis and treatment of end-stage liver disease complicated by infections.

End-stage liver disease (ESLD) is a life-threatening clinical syndrome and when complicated with infection the mortality is markedly increased. In patients with ESLD, bacterial or fungal infection can induce or aggravate the occurrence or progression of liver decompensation. Consequently, infections are among the most common complications of disease deterioration. There is an overwhelming need for standardized protocols for early diagnosis and appropriate management for patients with ESLD complicated by infections. Asia Pacific region has the largest number of ESLD patients, due to hepatitis B and the growing population of alcohol and NAFLD. Concomitant infections not only add to organ failure and high mortality but also to financial and healthcare burdens. This consensus document assembled up-to-date knowledge and experience from colleagues across the Asia-Pacific region, providing data on the principles as well as evidence-based current working protocols and practices for the diagnosis and treatment of patients with ESLD complicated by infections.