Hata, D. Jane

SUMMARY Bloodstream infections (BSIs) are a significant cause of mortality and morbidity. Rapid identification of pathogens and detection of a few resistance markers from positive blood cultures are now possible through the increased availability of commercial rapid diagnostic tests, including nucleic acid amplification tests and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. This document describes the clinical utility of rapid diagnostics performed on positive blood cultures and provides evidence-based laboratory medicine guidelines for using rapid tests to diagnose BSIs in hospitalized adult and pediatric patients. This guideline was developed for use by medical (a.k.a. clinical) microbiologists, medical laboratory professionals, infectious disease clinicians, pharmacists, hospital administrators, healthcare providers, and other stakeholders associated with BSIs. A panel of experts, including medical microbiologists and experts in systematic literature review, was assembled to formulate the Population–Intervention–Comparison–Outcome (PICO) question, review the literature, and provide recommendations for using rapid tests to diagnose BSI and improve patient outcomes. A comprehensive literature search of four electronic bibliographic databases (MEDLINE, Embase, CINAHL, and Cochrane) was conducted to identify studies with measurable outcomes. The panel followed a systematic process, which included a standardized methodology for rating the certainty of the evidence and strength of recommendations using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. The panel evaluated the literature to answer the question: Does using rapid diagnostic tests improve clinical outcomes in adult and pediatric patients hospitalized with a BSI? Peer-reviewed literature was available to address three outcomes, including time to targeted therapy, mortality, and length of hospital stay. In general, the quality of the evidence was low to moderate due to the paucity of controlled, randomized clinical trial studies. However, eight recommendations were made based on evidence derived from the systematic review of the published literature. To answer the PICO question, the expert committee recommended using rapid diagnostic tests combined with active communication to decrease the time to targeted therapy and length of stay (strong recommendation). While the strength of the evidence for the impact on mortality is low, the panel supports using rapid tests to impact these outcomes. A summary of the recommendations is listed in the Executive Summary, which includes a detailed description of the background, methods, evidence summary, and rationale that supports each recommendation in the full text.

Abstract Background Many molecular gastrointestinal pathogen panels (GIPs) are Food and Drug Administration (FDA) cleared but it is still unclear how to best utilize these new diagnostic tools. GIPs are highly sensitive and specific, simultaneously detect multiple pathogens in one reaction, and can shorten the overall time of diagnosis for infectious gastroenteritis but are also expensive with relatively poor insurance reimbursement. Content In this review, we take a comprehensive approach to discuss issues with utilization of GIPs from a physician perspective, and implementation from a laboratory perspective. The information presented is to assist physicians in deciding on appropriate use of GIPs in diagnostic algorithms for their patients, and to provide information to laboratories that may be considering the addition of these powerful diagnostic assays to their test menu. Some of the important topics discussed are inpatient vs outpatient use, the appropriate panel size and organisms to include, interpretation of results, laboratory validation, and reimbursement. Summary The information in this review provides clear guidance to both clinicians and laboratories in deciding the best use of GIPs for a specific patient population. While this technology provides many benefits over traditional methods, it can also complicate result interpretation and comes with a high cost, which necessitates the need for use recommendations.

Abstract Objective Using a US Food and Drug Administration (FDA) emergency use authorization (EUA) reverse transcription polymerase chain reaction (RT-PCR) method, we examined the analytic performance accuracy of saliva specimens as compared to nasopharyngeal (NP) specimens in symptomatic patients. Correlation between test results and symptoms was also evaluated. Methods Over a 5-week period in 2020, 89 matched saliva and nasopharyngeal swabs were collected from individuals exhibiting symptoms consistent with SARS-CoV-2. Specimens were tested with an FDA EUA-approved RT-PCR method, and performance characteristics were compared. Results The concordance rate between saliva and nasopharyngeal testing was 93.26%. The mean cycle threshold value of saliva when compared to the NP specimen was 3.56 cycles higher. As compared to NP swab, saliva testing demonstrates acceptable agreement but lower sensitivity. Conclusion When compared to a reference method using NP swabs, the use of saliva testing proved to be a reliable method. Self-collected saliva testing for SARS-CoV-2 allows for a viable option when trained staff or collection materials are in short supply.

AbstractSolid organ transplant recipients are at increased risk of acquiring devastating infections with unusual pathogens. Nocardia are aerobic actinomycetes that affect the lungs, brain, skin and soft tissue. Cladophialophora species are dematiaceous fungi that overwhelmingly cause infections in the brain. Both organisms carry a high mortality rate. We present the first reported renal transplant case with Cladophialophora bantiana involving the renal allograft with concurrent invasive nocardiosis involving the lungs and brain.

Context.— Candida auris is an emerging yeast species that was first described in 2009. This ascomycetous yeast is notable for resistance to azole antifungal agents, for environmental persistence, and for its ability to contaminate health care environments, resulting in patient colonization and nosocomial infections. Objective.— To review the state of current knowledge addressing challenges in the accurate identification of C auris in the diagnostic microbiology laboratory, including application of phenotypic, proteomic, and genomic methodologies; characteristics that may predispose the human host to acquiring C auris; transmission; clinical presentations; treatment modalities; environmental decontamination; and infection prevention in health care settings. Data Sources.— The PubMed search engine was used to access peer-reviewed literature published from 2009 to 2019. Conclusions.— The rapid emergence of C auris has presented unique challenges for the areas of laboratory diagnostics and infection prevention and in options for antifungal treatment, which are limited. The current lack of established antifungal susceptibility test breakpoints complicates therapeutic decision making. Enhanced awareness of this pathogen is essential to monitor outbreaks and to reduce the risk of spread within health care environments.

ABSTRACT Since the emergence and dissemination of Zika virus (ZIKV) in late 2015, our understanding of the biology, transmission, clinical disease, and potential sequelae associated with infection has markedly expanded. Over the past 2 years, the number of diagnostic assays for ZIKV has increased from none in 2015 to 5 serological assays and 14 molecular assays in 2017, all with emergency use authorization granted through the U.S. Food and Drug Administration. Here we provide an update on ZIKV, addressing what we have collectively learned since the outbreak began, including a summary of currently available diagnostic assays for this virus.

We describe a case of human infection with Gongylonema pulchrum acquired in southeast Georgia. The patient presented with intermittent yet persistent nausea and vomiting for months. This case describes the need for extraction of worms on two occasions each followed by courses of albendazole treatment. Gongylonema pulchrum infections with high worm burden may relapse after extraction of the worm and a 3-day short course of albendazole therapy. Longer courses of albendazole may be indicated in selected circumstances.

We present a 49-year-old female with one year of intermittent fevers, chills, night sweats, and significant weight loss. Liver and lung biopsy showed evidence of a granulomatous process. Blood and liver biopsy cultures yielded growth of presumedMycobacterium interjectum, thought to be related to a disseminated long-term central venous catheter infection. She successfully received one year of combined antimicrobial therapy after catheter removal without recurrence of disease.M. interjectumhas been previously described as a cause of lymphadenitis in healthy children and associated with pulmonary disease in adults, although other localized infections have been reported. This is the first case described of a disseminatedM. interjectuminfection with bacteremia, hepatic and pulmonary involvement associated with a long-term catheter infection.