Clinical Microbiology Newsletter最新文献

The human and organizational burdens of sepsis can be reduced by early recognition, diagnosis, therapy, and systems that support more effective management. The World Health Organization's (WHO's) 2020 Global Report on the Epidemiology and Burden of Sepsis will add importance to the clinical laboratory's role of monitoring blood culture metrics. The report details strategies for future efforts to characterize the global impact of sepsis more accurately, to improve the characterization of and differences in epidemiology, and to make estimates of disease burden more accurate. As the WHO is working toward improved global sepsis monitoring, re-assessment of the way clinical laboratories can contribute to this effort are long overdue at the local, national, and global levels.

Clinical laboratory dogma describes the importance of blood cultures (BCs) and optimization of BC processes, with documented impact on patient care. The BC is considered a first-line investigation for the microbiological diagnosis of sepsis, bacteremia, and fungemia and can detect a wide variety of microorganisms at a relatively low cost. Once microbes are detected in BC broth, subcultures yield microbial colonies for subsequent identification and antimicrobial susceptibility testing, and information is incorporated into the final BC result. However, the impact of BCs and the speed at which BCs are collected, incubated, and reported are minimized in the “surviving sepsis” literature, except for BC collection prior to the administration of antibiotics. Most hospital quality efforts focus on compliance with the 1-, 3-, and 6-h sepsis bundles with limited focus on the contribution of microbiology's role in rapid incubation, pathogen reporting, and other diagnostics that drive antimicrobial de-escalation and escalation protocols.

Clinical microbiology and laboratory medicine bear responsibility to ensure that BCs are collected properly and in a timely manner; that they are rapidly transported to the laboratory and incubated quickly; and that results are achieved and reported in a timely, reproducible, and accurate fashion. The quality metrics we discuss are not all required by inspection agencies; however, considering the initiatives to reduce the human cost of sepsis, attention to best practices is useful to optimize BC performance and BC yield. Examples of blood culture quality monitors and metrics are listed for laboratory consideration. Each laboratory may have unique situations in which one or more of the monitors may prove to be useful.

In the fight to eradicate hepatitis C virus (HCV), recent advances have provided both challenges and opportunities in our current laboratory approach for screening, diagnosis, and therapeutic response monitoring. Highly sensitive molecular assays have replaced serological confirmatory assays, while direct-acting antivirals have replaced interferon-based approaches, providing new weapons in the battle against chronic HCV infection. Aligned with these developments, the Centers for Disease Control and Prevention, U.S. Preventive Services Task Force, and American Association for the Study of Liver Diseases have recently updated guidance on the populations that should be offered testing and the methods and strategies to effectively do so. This review describes the details of these opportunities and the impacts of new guidance on laboratory evaluation in both routine and unique populations at risk for or infected with HCV.

Over the last few years, there have been numerous discussions on the American Society for Microbiology’s clinical listservs (DivC, and ClinMicroNet) regarding sterility testing of cell and gene therapy products and environmental monitoring and gloved fingertip testing for hospital pharmacies. Clinical microbiology laboratories have often been asked to assist with testing due to the on-site proximity of laboratory equipment and microbiological expertise within the hospital environment. The role of the clinical microbiology laboratory in this setting, however, is questionable due to major differences in test requirements and regulatory oversight. Here, we provide a side-by-side comparison of clinical versus current good manufacturing practices microbiology laboratories to provide guidance to those that are currently assisting with or have been asked to assist with sterility testing of manufactured biopharmaceutical products that have become common frontline treatments in modern medicine.

Leptospirosis is a globally widespread spirochetal infection spread from animals to humans. Infections are common in settings of endemicity, primarily in tropical regions of the world. Leptospirosis is typically a self-limited febrile illness but may progress to potentially fatal multiorgan system failure. Patients often present with a nonspecific acute febrile illness that is clinically difficult to distinguish from other similarly presenting infections endemic to tropical regions, including dengue fever, influenza, and malaria. A high index of suspicion is essential to early identification of patients who may benefit from antimicrobial therapy. Diagnostic testing is key to both recognition of early infection and outbreak investigation, typically in the setting of water exposure after heavy rainfall and flooding. This review focuses on the epidemiology, clinical manifestations, and laboratory diagnosis of leptospirosis, including nucleic acid amplification tests, culture, direct detection, and serological approaches.

Automated antimicrobial susceptibility testing (AST) is the standard clinical diagnostic for antibiotic resistance. The polymerase chain reaction and genome sequencing offer alternative molecular AST approaches. This review compares practical advantages, disadvantages, and advances across the three AST methods for clinical diagnosis of antibiotic resistance with an eye toward coordinated hybrid approaches leveraging adaptive artificial intelligence that responds to patient demographics, vital signs, and diagnostic test results against a backdrop of evolving epidemiology and local outbreaks monitored through coordinated public health surveillance.

Viral infections are a major cause of morbidity and mortality in patients undergoing solid organ or hematopoietic stem cell transplantation. Due to their immunocompromised status, transplant recipients are at a higher risk for community-acquired and reactivated viral infections. Serologic screening prior to transplantation can assist with risk stratification of patients and guide decisions regarding the use of pre-emptive antiviral therapy. Following transplantation, molecular testing has become the most common method to detect viral infections, with histopathology of infected tissue often being required to confirm a diagnosis. Quantitative nucleic acid amplification tests have been the standard to detect and monitor viral infections in transplant patients; however, important challenges remain, including lack of standardization across many testing laboratories, limited availability of FDA-approved viral load assays, and the absence of universal viral load thresholds that can be used to diagnose disease and guide management decisions.